Sports nutrition and metabolism Flashcards

Question

What does adipose tissue store?

Answer 1

Triglycerides

Answer 2

80-100g of glycogen but can break this down into glucose and transport in to the blood This is down by glucose - 6 -phosphatase

Answer 3

4-5mmol/l (20g) Can be transported into muscle

Answer 4

Muscle has 300-400g of glycogen, in athletes can go up to 900 g

Answer 5

yes It also depletes quicker with more intense exercise Same with liver glycogen Therefore muscle glycogen is essential for short duration exercise, gets used up so not utilised in longer bouts of exercise

Answer 6

Week before a race you would do one hard bout of training, followed by no training at all and 3 days of low CHO intake, then 3 days of high CHO intake before race day Problems: Hypoglycaemia in low CHO = low blood blood sugar Difficult to find food with no carbs GI distress Poor recovery Poor mental state from no training

Answer 7

Slowly decrease training, whilst slowly increasing CHO intake No difference compared to the classical after 60 minutes of exercise

Answer 8

Diet high in CHO resulted in Increased CHO oxidation Maintains higher blood glucose Improves physical performance

Answer 9

Yes for: Repeated sprints Intermittent sports lasting greater than an hour Exercise lasting more than 90 minutes No for: Short and explosive Kess apparent if ingesting CHO during exercise

Answer 10

Start exercise with sufficient muscle glycogen, don't need way more Eating CHO rich for 2 days prior to a race decrease training EE reduced so not just ear more A carbohydrate intake of 5-7 g/kg per day seems to be sufficient in the majority of cases (with low EE) GI athletes need to be careful

Answer 11

Maximise glycogen in liver and muscle Improves performance CHO are most important 1-4g/kgBM - lower if very close to the event Avoid low GI and avoid fat, need to get all food out of stomach before running to avoid runners trots Practice the routine

Answer 12

Transient fall in plamsa glucose at exercise onset Increased CHO oxidation and accelerated glycogen breakdown Blunting of Fatty acid mobilisation and fat oxidation - good for short exercise as want to prioritise carbs Important if cannot take CHO in during exercise

Answer 13

Causes large rise in plasma glucose and insulin Which may then lead to hypoglycaemia during exercise This is due to large rise in plasma glucose and insulin, which can then lead to reactive/rebound hypoglycaemia during exercise Can manipulate of ingested CHO to help tis (lower are better), also low GI food and just don't eat This is hypothetical and performance should be fine

Answer 14

Prevention of the depletion of blood glucose, and muscle and liver glycogen Maintain hydration Duration of event? How much CHO? (duration, intensity, GI ability) Type and form of CHO? (gel /solid/ monosachharide

Answer 15

Yes will find out why in a few videos time

Answer 16

Higher levels of oxidation of glucose than oxidation

Answer 17

It doesn't keep on getting bigger the more carbs you eat, maxes out round 1g/min can't digest it quick enough, or absorb it ``` Rapidly oxidised: (up to 1g/min) - Glucose Sucrose Maltose Maltodextrins Amylopectin ``` Oxidised at lower rates (up to 0.5g/min) ``` Fructose (liver) Galactose (liver) AMyose Isomalutose Trehalose ```

Answer 18

Combined ingestion - means that different transporters are utilised

Answer 19

Glucose and fructose (>60g/h glucose) Maltodextrin and fructose (>60g/h maltodextrin) Glucose, sucrose and fructose (>60g/h glucose and sucrose) If you can tolerate higher levels of carbs (120g/h) then during hard exercise can reduce exercise induced muscle damage markers such as creatine kinase, lactate dehydrogenase, GOT Also performance is enhanced by using combinations

Answer 20

Glucose activates parts of the brain which improves performance LAB REPORT IMPORTANT Glucose increases power and TT time when cycling, works better when you are in a fasted state

Answer 21

``` Mix and match of: Water CHO drinks Gels Bars FOod ``` Low in fat and fibre Protein if over 4 hours long Absolute amount not per bodyweight - it's about how quickly you can get it in 200ml every 20 min = better than 50ml every 5 min, makes a balance between stomach too full and just right Practice is most important

Answer 22

CHO can improve endurance capacity over 2 hours, but also high intensity exercise lasting around 75 min CHO ingested during exercise will spare liver glycogen and can completely block hepatic glucose output Exogenous CHO oxidation rates of a single CHO peaks at 1-1.1 g.min^-1 Ingestion of multiple transportable CHO can increase exogenous carbohydrate oxidation rates by 20-50%

Answer 23

Major storage from of fats in the body 3 fatty acids react with one glycerol molecule to produce a triglyceride molecule This is done via a condensation reaction = esterification (water is removed)

Answer 24

Fatty acids vary in (carbon chain) length and can be classified as short (4 or less) (SCFA), medium (6-12) (MCFA) or long (>14) (LCFA) The longer the chain length, the more solid and less liquid a fatty acid becomes at room temperature More we eat is long chain fatty acids

Answer 25

saturated = all hydrogen bonds Unsaturated = missing hydrogen bonds (has double carb bonds)

Answer 26

In nature they are cis Trans form due to processing e.g. heat and light

Answer 27

Essential = can't be made in the body so has to be obtained by the diet Non-essential = can synthesis in the body from specific precursors Omega end = the end away from the Carboxyl complex Omega number = number of carbons away from the omega end in which the closest double bond occurs

Answer 28

The ratio of n-3/n-6 PUFA in cell membranes leads to different set of intracellular mediators produced Higher n-3 leads to less inflammatory mediators produced Studies in illness, disease in human and animal confirm this effect, which is modulated by dietary intake

Answer 29

Provides a basically infinite store of energy during exercise

Answer 30

Fat has to be transported in aqueous solution (blood) Done via chylomicrons You have very low, low and high density lipoproteins

Answer 31

NO Fat must go through complex set of regulatory reactions to get into the mitochondria, then can enter the TCA cycle to produce ATP So its slower than producing energy from carbs

Answer 32

Fatty acid translocase/CD36 and fatty acid binding protein take the long chain fatty acids from circulation into the cytosol Join a pool from the intramuscular triglyceride store as well The long chain fatty acids are very inert so become activated by Co enzyme A (CoASH), forming Acyl-CoA This can now enter the mitochondria through the carnitine shuttle, achieved through the CPT1, CACT, and CPT2 enzymes Ready to undergo beta oxidation to make ATP This is why fat can't sustain contractions at 75% VO2 max, it is too sluggish

Answer 33

As we exercise we reduce the amount of adipose tissue we have Oxidative capacity and insulin sensitivity are markers of good metabolic health as we exercised more, restricted calories, are metabolic health increases, and if we are inactive, obese and on high fat diets it would decrease The more fat we get the more is stored as intra myocellular lipids as expected at one end of the scale As you get leaner the intra myocellular lipids levels drops, but when you keep on training on the scale of athlete they increase above what someone who is obese or type 2 diabetic

Answer 34

In athletes stored directly proximal to the mitochondria Also in athlete normally in smaller droplets = larger SA to volume ratio so can be used quicker Therefore most readily available fat store in the body Obese individual harder to access the fat and use it effectively

Answer 35

Plasma fatty acid - 0.004kg, 16KJ Plasma triacylglycerol, 0.004kg, 160 KJ Adipose tissue - 12kg, 40,400KJ Intramuscular triacylglycerol - 0.3kg, 10,800 KJ

Answer 36

Before that use carbs and fats equally After that fats drops massively and carbs is increased

Answer 37

Want fatty acids that can be transported to the muscle for fuel These are made from lipoprotein lipase breaking triglycerides, or Adrenaline released by exercise causing lipolysis through hormone sensitive lipase causing triglycerides to turn into fatty acids Increase in insulin (released after a meal) causes lipogenesis, fatty acids turned into triglycerides Problem is actually that fewer fats actually being able to get into the muscle cell - even though the supply of fats is enough The ability of the cell to take them up is not actually impaired, so the decline must be intracellular Co enzyme A exists in small amounts in the cytosol and mitochondria to form Acyl-CoA, but it is also needed for beta oxidation of Acyl-CoA to Acetyl-CoA Co enzyme A also needed in the carbohydrate pathway, when this increases so does this demand Same problem with Carnitine which takes Acyl-CoA across the mitochondrial membrane, it is also required on the carbohydrate side to form acetlycarnitine

Answer 38

yes. it enhances fat oxidation

Answer 39

Where fat oxidation peaks Around 50-65% achten et al 2002

Answer 40

Increase endogenous fat availability, increasing fat oxidation and spare carbohydrate - good for performance Can we increase this in the diet and should we?

Answer 41

Increases fat oxidation, and spares muscle glycogen use Without heparin does not help, as only triglyceride levels have increased as not being converted quickly to fatty free acids Overall pre exercise fat feeding does not help exercise performance

Answer 42

It's not easy to increase fatty acid availability When increased you do increase fatty acid oxidation This doesn't help with exercise performance Regardless of the length of chain of fat feeding Why doesn't it help? and if supplementing is not possible can chronic feeding be used as a practical strategy

Answer 43

Favourable changes in substrate use with high fat diet They have adapted to be able to utilise fat more effectively

Answer 44

No, need a set amount in the diet to maintain IMTG stores, and too much and impair glycogen storage

Answer 45

High carb by far.

Answer 46

If too low: There is progressive depletion of IMTG Minimum fat intake is required to maintain IMTG stores ( a key energy source for endurance performance) If too high: Results in greater fat oxidation Also results in lower muscle glycogen storage This reduces performance, particularly during higher intensity events which rely on carbohydrate oxidation This could also be due to a decrease in the efficiency of CHO use during more intense exercise

Answer 47

Have people of high fat diet in weeks leading up to performance so adapt to be able to perform more fat oxidation Then before performance have a high CHO diet to replenish glycogen stores Because: Potentially elevated ketones are shown that they increase RPE High fat diet make it difficult to reach a 'top gear', as their ability to move carbohydrate through the rate limiting step of pyruvate dehydrogenase is reduced The high fat diet has deprimed the carbohydrate adaptations the body has

Answer 48

High carb is better, good endurance exercise is also normally performed higher than 75% VO2 max as this is strongly CHO dependant So under most conditions Fat adaptation is not useful for exercise performance

Answer 49

Blood: Increased free fatty acids, means less carbohydrate stores used Muscle: Altered {K+} Blood lactate concentration Increasing Ca handling = increasing the power of muscle contractions Brain: Increased motor unit recruitment Adenosone antagonism = decreased rpe and pain Increases reaction time, alertness and mood = anti fatigue effects

Answer 50

Phosphocreatine supply Low muscle pH - acidosis Extracellular potassium accumulation - altered excitability Central fatigue

Answer 51

Our body weight If very active can double;e or triple

Answer 52

The integration of fuel metabolism is crucial to generating large amounts of ATP Important in the current day

Answer 53

At any time point the energy required by the cells of our body (metabolic rate) is almost always provided by both fat and CHO utilisation Different circumstances can require different amounts of energy At any given energy expenditure there can be a different contribution of dat and CHO to this energy expenditure

Answer 54

Skeletal muscle is 40-50@ of body mass Responsible for 20-30% of resting oxygen consumption Mediates over 75% of all insulin mediated glucose disposal under normal physiological conditions Primary depot for this disposal of nutrients

Answer 55

Fat is boss in the integration of fuel metabolism - under most conditions it's what regulates metabolism over carbohydrates Fatty-acid pathway can inhibit the glucose pathway The acceleration of fat metabolism happens over carbs when we are fasting End product inhibition, fatty acid cycle produces Acetyl-CoA, which is also the end product of glucose metabolism, so if the glucose pathway isn't even working hard there is an imbalance between pyruvate which should be converted into the abundant acetyl-CoA which has now been made harder Acetyl-CoA also enters the TCA cycle and one of the products it produces is Citrate, which in excess diffuses across the mitochondrial membrane into the cytosol, where it inhibits phospofructokinsase, and essential enzyme is glycolysis This results in a build up of glucose-6-phosphate, which inhibits hexokinase which is required to activate the glucose molecule Empirical data supports all of this

Answer 56

Increasing plasma FFA (via lipid and heparin infusion): (Odland et al, 1998, 2000). • Suggests regulation at PFK. 33% ↓ thigh glucose uptake during moderate intensity knee extensor exercise (Hargreaves et al, 1991). • Suggests regulation at GLUT4. ↑ fat oxidation by 15% and ↓glycogenolysis by 50% at >80% VO2max. ↔ PDC activity and muscle contents of acetyl-CoA, citrate, and G-6-P. ↓ free ADP and AMP. (Dyck et al, 1993, 1996; Romijn et al, 1995). • Suggests regulation at Glycogen phosphorylase.

Answer 57

Eat carbs meal Carbs digested and absorbed as glucose which is distributed in circulation As glucose passes by the pancreas, pancreatic beta cells release insulin Glucose is impermeable so needs an active transporter (insulin) More simple carbs = quick insulin peak (easier to breakdown) More complex carbs = more prolonged peak (harder to breakdown) Insulin attached to insulin receptor on cell membrane Phosphorylation and therefore activation of IRS-1 IRS-1 stimulates PI3kinase, this stimulates GLUT4 (a muscle specific transporter) to go from vesicles within the cell into the cell membrane PI3kinase also stimulates the protein AKt, which stimulates GLUT4 as well GLUT4 makes the cell membrane essentially permeable to glucose Akt also directly regulates the pyruvatedehydrogenase complex

Answer 58

Aerobically converted from pyruvate into acetyl-CoA Anaerobically converted from Pyruvate into lactate Stored as glycogen

Answer 59

Yes, it helps to reverse the randle cycle But it only impairs oxidation of long chain fatty acids, not medium chain This switch is controlled by CPT1

Answer 60

Rise in glucose results in an increase Acetyl-CoA Produced in excess to what the TCA cycle can handle So it is converted by the ACC enzyme into Malonyl-CoA which inhibits CPT1

Answer 61

>2fold ↑ in fat oxidation (due to depleted pre-exercise muscle glycogen content) during exercise at 65% VO2,peak. ↔ muscle malonyl-CoA compared to control. (Roepstorff et al, 2005) No association between muscle malonyl-CoA content and fat oxidation rates during prolonged moderate-intensity exercise or graded-intensity exercise. (Odland et al, 1996, 1998; Dean et al, 2000) so doesn't work in humans

Answer 62

Acetyl-CoA converted into acetylcarnitine and moved into the cytosol by CAT and CACT reacting acetyl-CoA and Carnitine Acetyl-CoA can act as a metabolic sink CoA is also produced which can be used by the mitochondria This overall causes a decrease in free Carnitine, so can't act as a cofactor for CPT1 to shuttle fatty acids (acetyl-CoA) into the mitochondria -this is the limiting step everyone believes right now

Answer 63

Broad et al. (2005) found no effect of oral L-carnitine supplementation for 4 weeks (3g/day) on carbohydrate and fat metabolism or on exercise performance Vukovich et al. (1994) reported no significant effects on fat or carbohydrate metabolism during exercise at 70% VO2max after 14 days (6g/day) supplementation of L-carnitine. Wächter et al. (2002) also concluded that oral L-carnitine supplementation for 3 months (4g/day) did not affect exercise performance. Importantly, Wächter et al. (2002) and Vukovich et al. (1994) reported that L- carnitine supplementation did not alter muscle carnitine content. Does not work from these studies, it works basically only in the muscle, so when you digest it there is an unfavourable concentration to get more in the muscle So you need molecules that bring the carnitine into the muscle, can use carbohydrates to do this Ben wall and colleagues shows it can work when it is up taken, can alter fat and carb oxidation, and can increase exercise performance by saving glycogen stores through driving fat oxidation (only lower intensities), but at higher % of Vo2 max where carnitine is a limiting factor for fat oxidation, it didn't actually help, what it did was reduce lactate accumulation What carnitine did was change its role from being used in CPT1 translation to the mitochondria, or it's role as a acetyl buffer depending on glycolytic flux So higher glycolytic flux (higher work intensity) drove carnitine to help form a metabolic sink for acetyl coA, more of it means it can be done in larger quantities, reducing pyruvate quantities and therefore lactate accumulation

Answer 64

The reduced responsiveness of skeletal muscle glucose uptake to normal circulating levels of insulin Can also be viewed as... Impaired ability of insulin to stimulate glucose oxidation (via PDC) Impaired ability of insulin to stimulate microvascular perfusion Impaired ability of insulin to stimulate amino acid uptake into muscle cells Impaired ability of insulin to inhibit muscle protein breakdown. Makes it harder to get glucose into the cell, therefore results in it being harder to use it to generate energy

Answer 65

Single blood sample Ratio of insulin to glucose in your blood using an equation Healthy in fasted = low in both Diabetes type 2 = high insulin and high glucose as it just isn't enough to get the glucose in the cell Or high glucose low insulin, as the pancreas has been stimulated so much it can't release much anymore One technique is looking at glucose disposal rate Gold standard is hyperinsulianemic clamp technique

Answer 66

Induce artificial high levels of insulin pumped into the body Glucose chased away into peripheral cells, so you inject glucose as well and look at the rate in which it gets put into cells Athlete will have fast rate Obese will have slow rate

Answer 67

Insulin resistance is usually brought about by increased energy intake, physical inactivity and/or the development of being overweight and/or obese. Insulin resistance is the direct precursor to frank type 2 diabetes. Type 2 diabetes is defined as resulting from a defect in both insulin sensitivity and 80% of type 2 diabetics are obese 2.75 million people in the UK now have diabetes, 2 million of which have type 2 diabetes. The total is forecast to climb to four million by 2025. Diabetes accounts for approximately a tenth of NHS budget each year, a total exceeding £9 billion. The complications of diabetes are numerous and include amputation, heart disease, kidney failure and blindness.

Answer 68

Obese people suffer from it From fasting to insulin stimulated they can't oxidise the glucose they have digested Can't switch between fat and carb oxidation

Answer 69

Big lipid droplets form in muscle Broken down to acyl-CoA Athlete can turn these over Obese can't, resulting in an accumulation of fatty acid intermediates, such as Ceramide and Diacylglycerol These stimulate the JNK pathway which can directly inhibit the IRS-1 which is needed for to pathway of insulin creating an effect within the muscle cell The IkKB and PKC pathways do the same to IRS-1 Overall this exacerbates the cycle build up of lipids

Answer 70

Excess lipid and adipose tissue release Il-6 and TNF-a cytokines can interfere with insulin signalling Interacts with JNK pathway as well

Answer 71

Muscle and plasma triglyceride Can do endogenous carbohydrate and plasma FFA

Answer 72

yes, so it is contraction stimulated glucose uptake Contraction increases concentration of Ca2+ and turns ATP broken down into AMP and ADP, this changes the charge of the cell, this ratio tells AMPK what to do AMP accumulates, AMPK tells the cell to breakdown Glycogen to provide ATP AMPK also tells GLUT4 to go to the membrane, and stimulates CPT1 to shuttle fats into the mitochondria Ca2+ increase stimulates PDC increase activity, as well as the enzyme CaMK which increases GLUT4 translocation the cell membrane

Answer 73

Secretagogoues: Sulphonylureas Meglinitinides Exogenous insulin Sensitisers: Biguanides Thiazoliddinediones AICAR Peptide analogous/agonists Exenatide These work at the metabolic level to increase metabolism

Answer 74

Chain (polymer) of amino acids Arranged into primary, secondary and tertiary (and quaternary) structures Contain Nitrogen

Answer 75

Transcription Translation (initiation, elongation, termination) Post translational modification

Answer 76

``` Provide structure Hormones Antibodies Transporters Enzymes Movement ```

Answer 77

The creation of new proteins from amino acids (as a result of initial transcription of the DNA)

Answer 78

The degradation of whole proteins back to constituent amino acids

Answer 79

The net result of muscle protein synthesis and muscle protein breakdown (synthesis -breakdown)

Answer 80

The breakdown of intracellular amino acids for energy production If oxidised not available for protein synthesis

Answer 81

The rate of transport of amino acids from one pool (eg. the plasma) to antlers (e.g. the muscle cell)

Answer 82

The amount of dietary amino acids (obtained from dietary protein) that is used by the tissue and organs of the body for the above processes

Answer 83

DNA to RNA = transcription RNA to Protein = Translation Results in a trait

Answer 84

``` Valine Isoleucine Leucine Lysine Methionine Phenylalanine Threonine Tryptophan Histidine ```

Answer 85

``` Glycine Arginine Glutamine Proline Cysteine Tyrosine Serine Asparagine ```

Answer 86

Glutamic acid Alanine Selenocysteine Aspartic acid

Answer 87

Primary = polypeptide chain order of amino acids, held together by peptide bonds that are made during the process of protein biosynthesis Secondary = B pleated sheet or alpha helix, hydrogen bonds Tertiary = The tertiary structure of a protein refers to the overall three-dimensional arrangement of its polypeptide chain in space. It is generally stabilized by outside polar hydrophilic hydrogen and ionic bond interactions, and internal hydrophobic interactions between nonpolar amino acid side chains quaternary = The quaternary structure of a protein is the association of several protein chains or subunits into a closely packed arrangement

Answer 88

Carbon skeleton Top of skeleton = COOH On the right = NH2 On the left = H On the bottom = R chain, this characterises it

Answer 89

It's removed by urea synthesis in the liver, then excreted as urine So the amino acid can actually be oxidised

Answer 90

The enzyme KIC via transamination and decarboxylation turns Leucine into isovaleryl - CoA with the byproducts glutamate and Co2 This then turns into Acetyl CoA or Acetoacetate

Answer 91

Intake protein through diet (50-100g a day) which forms plasma amino acid pool via digestion and absorption These amino acids are uptake by cells forming an intracellular amino acid pool This is when protein synthesis now occurs, (350g/day) Protein breakdown is also occurring going into the intracellular amino acid pool

Answer 92

Amino acids and ammonia go from the GI tract to the liver Amino acids go from the GI tract to skeletal muscle, breakdown of proteins here produces alanine which turns into glutamine and goes to the kidneys where glujconeogeneis occurs and glucose is formed which goes to the liver Liver excretes urea, glucose, triglycerides, and proteins

Answer 93

Nitrogen balance: Nitrogen excretion = nitrogen intake Need to know exactly what's being eaten, and what is being excreted (Sweat, urine, faecaes) You don't know what tissues storage is occurring in or what time Stables isotopes: Label a specific amino acid can trace where it is in the body eg. 13C-Leucine Can see how much is uptake from plasma amino acid pool into the intracellular amino acid pool Can see how much undergoes oxidation Can see how much incorporated into muscle protein through synthesis Can also see how much of this protein is then broke down

Answer 94

``` Habitual diet Protein intake Energy intake Hormones - insulin, steroids such as testosterone Exercise ```

Answer 95

``` Muscle hypertrophy Muscle strength Immune function Central fatigue Glycogen re-synthesis Additional energy during exercise Specific function of individual amino acids Effects on muscle damage Oxidative damage Increasing the synthesis of specific proteins? Mitochondrial/oxidative proteins? ```

Answer 96

1-2% per day (300g-600g muscle tissue)

Answer 97

During exercise amino acid metabolism increases (still low compared to carb and fat metabolism, it's 1-10%) to produce energy, it's lower pre and post exercise Therefore whole body protein synthesis is higher pre and post exercise When we begin endurance exercise the priority of the tissue is to produce energy = catabolic state Same showed on a training day in which nitrogen balance goes negative

Answer 98

8 physically active overnight fasted young men 2 trials one with and one without protein (both have carbs) 2h rest, 3h exercise at 60% VO2 max, 3h recovery Leg phenylalanine kinetics, fractional synthetic rate looked at No decline seen in protein synthesis as both were fed with carbs, but protein showed far larger protein synthesis. Exercise makes protein synthesis increase when having protein, but the breakdown from exercise is still too much that it's still net negative Protein breakdown was the same on all conditions

Answer 99

Not necessarily, have to look at breakdown as well

Answer 100

Adaptation to the mitochondria within the muscle = improved oxidative capacity More mitochondria/ better functioning mitochondria Oxidative enzymes in higher concentrations in endurance athletes compared to resistance trained

Answer 101

Training one leg to do endurance work compared to the other which is doing resistance will increase the endurance one endurance capacity and not the other sa as much

Answer 102

Endurance = increase in mitochondria Resistance = increase in myofibrillar proteins

Answer 103

Was found that protein increases myofibrillar but not mitochondrial protein synthesis - so not as good for the endurance athlete This evidence is not that researched however, seems still essential to not spend days in negative protein balance, Overall the findings in meta analysis are conflicting

Answer 104

Theory on how protein improves endurance exercise performance Its that fatigue may be associated with inadequate central nervous system drive to the working muscle Main theory is Serotonin Central Fatigue Hypothesis: Increased brain 5-hydroxytryptamine (5-HT) (Serotonin) concentration causes a deterioration in performance Serotonin synthesised in the brain from the amino acid tryptophan

Answer 105

Serotonin interferes neural drive - causing impaired CNS function, reducing exercise performance Serotonin is directly affected by Tryptophan (it's amino acid pre cursor) that arrives at the brain through the blood Brain barrier using a selective transporter This selective transporter is not very specific, and also allows other amino acid chains to cross the barrier, therefore there is competitive inhibition So less free tryptophan will get across the blood brain barrier if there are branch chain amino acids present Tryptophan circulates the body bound to Albumin and free fatty acids BCAA concentration depends on dietary protein intake and exercise Exercise causes more FFA to be released from the adipose tissue which binds onto Albumin increases the ratio in favour of tryptophan We are using the BCAA for exercise, so that makes the ratio worse BCAA's again

Answer 106

Blomstand et al 1991 Looked runners, only improved slower runners performance, but these slower runs all had lower rates of CHO ingestion as well

Answer 107

That placebo, tryptophan, and BCAA supplementation all had the same to time to exhaustion during cycling

Answer 108

Only if you have insufficient energy from food, and carbohydrate is better and easy to supplement with during exercise

Answer 109

In control body mass, fat mass, and leanness all decreased With increased protein, body mass reduced less, fat mass reduced the same, and lean mass decreased far less

Answer 110

You can be in calorie deficit and gain muscle 4 weeks of 40% hypolcaloric diet to induce weight loss 1.2 g protein per kg bw vs 2.4g protein per kg bw Resistance and HIIT training 6 days pre week In both Fat mass and Body mass dropped Protein high diet increased lean mass, the normal protein maintained lean mass

Answer 111

Meredith et al, 1989 Looked at 0.6, 0.9, or 1.2g protein/kg/d in endurance trained athletes Only when you got to 1.2g per day they were really in a nitrogen positive balance, showing could be making the adaptations Most endurance athletes surpass this from their diet anyways, so it's not normally a concern ``` So RDI = 1.2-2.0 g/kg Dependent on: Mode/intensity/duration of training Protein quality Likely that adequate energy in the diet = adequate protein, without supplementation ``` Timing relative to exercise is important: Protein ingestion in close proximity to exercise may facilitate muscle reconditioning Protein feeding during exercise does not appear to enhance exercise performance assuming adequate CHO is consumed To lose weight without losing muscle should have higher protein diets

Answer 112

1.76/g/kg/d for optimal adaptations

Answer 113

Amino acids Eating high protein meal will increase protein synthesis for up to 5 hours

Answer 114

You eat a meal Muscle protein synthesis goes up Insulin released which inhibits muscle protein breakdown Over time this will drop and your fed gains reduces This goes up and down resulting in a balance that is stable overall in a normal individual (oscillation) So there is mild anabolism and catabolism

Answer 115

Normal = 1-2% per day = 300-600g muscle tissue Following resistance training = 2-3% per day (600g-900g) But nutrition allows a positive balance and this net muscle protein accretion (hypertrophy)

Answer 116

Decreases during exercise Then after exercise increases above basal Exercise also increases breakdown levels over the next few days (adaptations taking place)

Answer 117

Cant ever be in a positive protein balance no matter how hard you train

Answer 118

If you only train one arm, there will still be positive muscle protein synthesis in your other arm

Answer 119

no More of what protein you eat after exercise will always become more muscle than normal

Answer 120

Yes it does, small but significant

Answer 121

Amount? Type? Other macronutrients? Food? Timing?

Answer 122

Around 20g, going up to 40g only increases it a little bit more, this 40g will become more needed when doing a whole body workout Therefore its more about the muscle you activate, rather than the amount of muscle you have

Answer 123

Insulin release, increases perfusion to the muscle (amino acid amount getting delivery to the cell and into the cell), Depends if they are rate dependent steps However in reality they don't help, the already modest insulin response from protein is enough to stimulate maximal muscle protein synthesis

Answer 124

No, it just slows down the digestion and absorption of amino acids

Answer 125

Postprandial insulin response (carbs isn't need to make it valid) Bioavailability Digestion and absorption kinetics Amino acid composition

Answer 126

Casein (80%) Whey (20%) Whey quickly absorbed Casein very slow absorbed Hydrolysed casein = meaning its been pre digested, it's still not as fast as whey so something else is happening This difference is due to the peak (richness) of essential amino acids, especially Leucine

Answer 127

yes, tends to have a better response in protein synthesis rates and adaptation over a longer period

Answer 128

In rested and exercise fasted milk was slightly better In rested fed and exercise fed mycoprotein was better (higher protein synthesis rate) So whole food is most likely more anabolic than isolated proteins

Answer 129

Strength and hypertrophy changes are very similar if not in favour on the vegan diet But needs more data

Answer 130

Looked at 12h recovery from resistance exercise 80g fed to all volunteers as 1) 8 x 10g every 1.5h (pulse) 2) 4 x 20g every 3h (intermediate) 3) 2 x 40g every 6 (bolus) Intermediate resulted in most protein synthesis

Answer 131

yes, also helps before sleep

Answer 132

Maximal anabolic response with 25-30g protein 5-6 meals per day 1.6-2.2g per kg body mass / day

Answer 133

Exercise sensitises the muscle tissue to the anabolic properties of nutrition during each and every meal for at least a 24h period 20-30g per post exercise meal will induce an optimal anabolic response We can look at the types of protein that would be most effective, select optimal sources or fortify those sub optimal sources Ideally each protein meal would be rapidly digestible, rich in essential amino acids, and leucine in particular (2.5-3 g of leucine) Protein is the only fundamentally anabolic nutrient, as such additional energy from other macronutrients from an anabolism perspective, but clearly being part of real food has benefits Protein meals should be adequately spaced apart to gain the most anabolism from each meal Presleep protein ingestion offers a unique timing opportunity to improve overnight muscle protein accretion

Answer 134

Firmicutes and Bacteridetes There are also fungi, archaea, viruses and parasites within the gut

Answer 135

Protection against pathogens Synthesis of vitamins Immune system Promotion of intestinal angiogenesis Adipocyte function Short Chain Fatty Acid production by fermentation of dietary fibre Modulation of central nervous system

Answer 136

Increase in diversity and SCFAs+, and decrease in gut permeability If these are all reversed bad things happen: Dysbiosis - reduction in protection against autoimmunity Increased cytokine production eg. IFN-y, meaning a reduction in Tree cell production Increase in inflammation

Answer 137

Immune function Appetite regulation Mood Metabolism Vascular function

Answer 138

Birthing process - c section or not Infant feeding method Stress (exercise, metabolic, psychological) Diet Pharmaceuticals geography Lifecycle stages

Answer 139

Increased microbial diversity and increased SCFA

Answer 140

Fecal samples Then: DNA-Based approaches = metagenomics RNA-based approaches = metetranscriptomics Protein based approaches = metaproteomics Metabolite based approaches = metabolomics

Answer 141

Exercise performance results in: Higher microbial resistance Higher abundance of beneficial Akkermansia, Veillonelaa, Prevotella Selection advantage for lactate utilising bacteria Benefits of a good microbiota for the athlete: Production of bioactive metabolites (SCFA and neurotransmitters) Maintenance of intestinal barrier function Modulation of immune system Improved energy harvest and utilisation Regulation of muscle metabolism

Answer 142

GI distress, as there is a reduction of blood flow to the gut

Answer 143

Food for bacterial growth Can only be metabolised by the gut bacteria and not the human host

Answer 144

Live bacterial cultures

Answer 145

Mixture between pre and pro biotics

Answer 146

The various strains help to relegate the levels of other bacteria in the gut Modulate immune responses to invading pathogens Prevent humour formation Produce vitamins

Answer 147

Several type inhabit the human gut Involved in the production of vitamin K2 (essential for blood clotting) and help to keep bad bacteria in check Some strains can lead to illness

Answer 148

Beneficial varieties produce vitamins nutrients, boost immunity and protect against carcinogens

Answer 149

C Jejuni and C coli are the strains most commonly associated with human disease. Infection usually occurs through the ingestion of contaminated food

Answer 150

Common cause of post surgical infection

Answer 151

Most harmful following a course of antibiotics when it is able to proliferate

Answer 152

Stimulate the central nervous system with a marked effect on: Mental function and behaviour Producing excitement and euphoria Reduced sensation of fatigue Increase in motor activity

Answer 153

1,3,7 - trimethlyxanthine Takes an hour to have maximal ergogenic effect Half life of 5 hours Metabolism affected by: Hepatic dysfunction Habituation Removed from banned list in 2004

Answer 154

Central effects - stimulant: Binds to adenosine receptors in the brain, displacing adenosine which has a stimulant effect ``` Increased lipolysis (sympathetic activation): Increased availability of fatty acids through the sympathetic system being activated, so more carb sparing so improved performance: ``` Reduced extracellular potassium Sarcoplasmic Reticulum Ca2+ release: Improving calcium handling (binds to troponin, allowing myosin to be bound and cross bridge cycling can occur - release and uptake of calcium into the sarcoplasmic reticulum, improving contractility, faster time to peak force Caffeine preserves the resting membrane potential of the nerve impulse in the muscle, meaning even after being stimulated a lot from exercise can still generate action potentials

Answer 155

Transcranial magnetic simtulation, causes a contraction in a specific area of the motor cortex, which makes a specific muscle contract Used to look at how caffeine affects muscle

Answer 156

Stimulate it and it causes the knee reflex action so stimulates muscle so stimulates the knee extensor muscles so can look at their function with caffeine or not

Answer 157

There is room for a stimulant to increase this max voluntary contraction Can also link at the time for the contraction to occur

Answer 158

Received 6 mg caffeine . kg^-1 or placebo 1 hour prior to performing exercise 5 bouts of single leg knee extensor exercises to fatigue Time to fatigue was recorded and they had 5 mins each time to recover Caffeine made exercise capacity far better, but you also see an increase in blood lactate (from doing more work) Muscle metabolites: Sets 2-5 is Per conc is far lower in caffeine condition, Muscle pH goes more acidic in caffeine condition, showing they are doing more work Overall benefit was from an increased voluntary activation ``` This is from: Increased contractility Increased relaxation rate Increased excitability Increased wave amplitude ``` ``` Conclusions: Increases in exercise capacity Delays fatigue Inceazed contractility? Increased voluntary activation Helpful where central fatigue is a key cause of poor performance ```

Answer 159

10 healthy untrained subjects Caffeine (6 mg.kg^-1) vs placebo Complete1h at 70% VO2max, 1h after ingestion of supplement Arterial fatty acid conc higher in caffeine, especially at the beginning of exercise Increased adrenaline due to caffeine Reduced extracellular potassium Sarcoplasmic Reticulum Ca2+ release: RER is the same, so no difference in fat and carbo oxidation Conclusions: Caffeine stimulates lipolysis at rest Appears to stimulate sympathetic nervous system activity No metabolic effects Lowers plasma potassium

Answer 160

10 subjects 3 trials 105 min @ 60%VO2max + time trial (calculated what work would have been done at 70% VO2max over 45 mins, then had to complete it as fast as possible) Placebo Cho (0.7g/min) Cho + caff (5mg/kg) No carb sparing shown, as affects of caffeine overwhelmed by carb dosing Caffeine + CHO = better performance (4.6% better performance)

Answer 161

Caffeine only prior to exercise (2.3% increase in performance) Caffeine ingestion before and during exercise (4.3% increase in performance)

Answer 162

3% increase in performance Magnitude of effects not influenced by Sex, age, VO2max, event, or timing prior to competition Performance benefits are greater for longer duration events Not effective for 800m performance and impaired subsequent sleep quality (Ramos-Campo et al, 2019.). (one study)

Answer 163

10 male amateur team sport players Repeated cyclic sprints to mimic team sports 2 x 36min halves - 18 x 4 sprints 5 mg.kg^-1 caffeine or placebo Caffeine showed increased world done and power output Faster reaction time

Answer 164

Increased small benefit to repeated and single jumping Same in single and repeated sprint Bit larger improvement to agility Improved running distance All these factors are cumulative

Answer 165

Improved muscular endurance, MVC strength, 1RM strength, isokinetic strength

Answer 166

Endurance trained participants: 11 female on oral contraception 16 male Randomised, double blind, placebo-controlled crossover trial Incremental test, 2 x familiarisation, 2 x performance trials (test were how fast can you do your 75% vo2max distance for an hour ) 3mg.kg^-1 90 min per exercise No sex differences found

Answer 167

13 well trained eumenorrheic triathletes no on oral contraception Randomised, double blind, crossover trial Placebo and caffeine (3mg.kg^-1) trials in: Early follicular Pre-ovulation Mid-luteal Found to have no effect

Answer 168

Improved cycling performance - more details on slides Peaks faster than a pill as well (peaks at 10 mins) 5 mins chewing gets 80% of caffeine out

Answer 169

that it gets less effective the more you take over a period of time so you would need a higher dose

Answer 170

over 12mg per kg body weight

Answer 171

yes at rest, not doing exercise, females more susceptible But caffeine does cause poor sleep quality

Answer 172

Reactive oxygen species (Radical and non radicals) Reactive Nitrogen species (Radicals and non radicals)

Answer 173

``` Environmental: Ultraviolet radiation Pollution Smoking Burnt food ``` Cellular processes: Oxidase enzymes Mitochdonrial respiration

Answer 174

``` Cell communication: SR Ca2+ release Glut 4 translocation Increased protein synthesis Metabolic regulation ``` Vasodilation Immune function

Answer 175

Oxidative damage: Damaging lipids: Peroxidation Cells membranes damaged - dysfunctional cells Reduced NO bioavailability - impaired blood vessel function Damage to body proteins: Oxidative modification - carbonisation, nitrosylation Altered function - aging DNA damage: Aging Cancer Triggers inflammation

Answer 176

Enzymes Non-enzymatic Nutritional: Vitmains Minerals Polyphenols

Answer 177

``` Flavonoids: Anthocyanidins = cyadnidin, peargonidin, peoonidin, delphinidin, perunidin, malvidin Falvonols Flavonones Isoflavones Flavanols ``` Lignans Other polyphenols Phenolic acids Stilbenes

Answer 178

Radical scavengers Only about 5-10% of dietary polyphenols go into circulation, rest are digested by microbiome which then can be used Due to his poor bioavailability, they are converted to prooxidants such as Semiquinones and quinones These then trigger increased synthesis of endogenous antioxidants by cells Also the actual antioxidants can inhibit ROS production

Answer 179

NADPH oxidase creates O2- radicals which with the product of the mitochondria produced H2O2 intracellularly Extracellularly NADPH oxidase and XO form O2- radicals which forms H2O2 When exercise occurs both their concentrations increase

Answer 180

``` Markets of oxidative damage (indirect): Protein carbonyl and nitrotyrosine F2 - isopostanes TBARS - thionbabituric acid reactive substances MDA- malondialehyde ``` Electron paramagnetic spin resonance (direct) Spin traps for specific radicals

Answer 181

In the middle, balance of cellular redox state

Answer 182

``` Ioninc gradients E-C coupling Central drive Substrate depletion By-product accumulation Muscle perfusion ``` ROS and RNS can contribute to these processes, so does antioxidant supplementation improve performance

Answer 183

Increased production of antioxidant enzymes For example ROS and RNS allows Nrf2 to unbind with Keap1, NRF2 then can fit into the cell and cause a antioxidant response element So exercise training increases antioxidant defences So does antioxidant supplementation block training adaptation

Answer 184

ROS and RNS can result in: Damaged cell membranes - leaky- impaired permeability Damaged proteins - altered function - transporters, enzymes, contractile proteins Inflammation - soreness, pain Can lead to injury which worsens inflammation and the immune response, which increases the ROS and RNS concs So can antioxidant supplementation improve recovery

Answer 185

Direct oxidant scavenger Cysteine donor to support glutathione function So acts as a radical scavenger as well as supporting gluthathione function

Answer 186

10 male triathletes Double blind crossover study 1200mg.d^-1 dor 9d (NAC (antioxidant in last flashcard) or placebo) Improved 5s, 10s and 15s sprint performance Conclusions: Favourable effects on oxidant balance Improved cycling sprint performance Better tolerance of increased training intensity Other studies suggest NAC better for endurance rather than sprint performance

Answer 187

Polyphenol Falvonol from the flavonoid family Widespread presence in fruits and vegetables Habitual intake = 5-13mg.d^-1 ``` Purpoted properties: Antiooxidant Anticarcinogenic Cardioprotective Ergogenic ``` 500-1000 mg quercetin per day resulted in 2.8% increase in endurance performance

Answer 188

257mg anthocyanin and 456mg total phenolics Saw higher blood lactate concentration in cherry when exercise was occurring, due to higher tissue saturation (better perfusion) meaning better removal of lactate from the muscle and into the blood 4.6% increase in performance with cherry Might be because of better cognitive function

Answer 189

38 active healthy mean Randomised to 6 week nutritional supplementation, twice per day Placebo or Vit C (400mg) and E (268mg a-tocopherol) 90 min intermittent shuttle running Bloods and muscle function tests Found no significant effects of antioxidant vitamin supplementation, some studies find it, some don't but mostly likely doesn't help recovery. Also they might stop adaptations to training

Answer 190

Found improved functional recovery Reduced amount of protein carbonyls and creatine kinase Mediated via reduced exposure to reactive oxygen species

Answer 191

Enhance functional recovery: Reduced oxidative damae Reduced inflammation Consume 1000mg.d^-1 for 3 days minimum prior to exercise Optimal mix, dose and timing still not known

Answer 192

Acetlycholine released from the axon terminal binds to receptors on the sarcolemma An action potential is generated and travels down the T tubule Ca2+ is released from the sarcoplasmic reticulum in response to the change in voltage Ca2+ binds troponin: cross bridges form between actin and myosin Acetlycholinesterase removes acetylcholine from the synaptic cleft Ca2+ is transported back into the sarcoplasmic reticulum Tropomyosin binds active sites actin causing the criss-bridge to detach

Answer 193

Glycogen depletion (can help with carb loading, but glycogen depletion isn't that important) Phosphocreatine depletion (can creatine load) Muscle acidosis (Can increase buffering capacity loading) - delaying the effect of acidosis (pH below 7, caused by the hydrogen ions associated with lactate)

Answer 194

Produces Hydrogen ions Monocarboylase enzymes can remove H+ and Lactate from the muscle Sodium hydrogen transporter, can take hydrogen out and put sodium into the muscle Sodium bicarbonate takes sodium out, and puts in bicarbonate (alkali) in The bicarbonate binds with hydrogen forming carbonic acid which can dissociate into carbon dioxide and water, which is better for the body to cope with So the alkali is neutralising the hydrogen ions

Answer 195

Potassium is important for membrane potential 2 sodium out, 2 potassium in Accumulate potassium out of cell Change with AP much smaller (now -55mv to 30mv, instead of -70mv to 30mv) Causes an issue with ability to generate force

Answer 196

As extracellular potassium increases, peak force decreases Same as extracellular potassium increases resting membrane potential increases When the membrane increases past -65mv there is a critical drop in the peak power that can be generated

Answer 197

When sodium biacarobonate was given as a supplement Arteries (what's going to the muscle): Hydrogen ions dropped Lactate stayed the same K+ ions decreased Veins (what's leaving the muscle): Lower hydrogen ions Higher lactate concentration (they exercised longer due to the supplement so lactate was allowed to increase further) Lower potassium concentration Exercised 25% longer

Answer 198

Extracellular anion Biocarbonate loading results in increases in blood bicarbonate pools Muscles become buffered Helps in events in which a low pH is a limiting factor (banned in horse racing)

Answer 199

0.4/kgBM, 30min at individual anaerobic threshold Time to exhaustion increased by 10%

Answer 200

5 x 65 sprint No difference in placebo compared to sodium bicarbonate in muscle H+ concentration But post workout increased muscle lactate concentration in sodium bicarbonate compared to placebo (so you have worked longer, so more lactate but your hydrogen ions haven't increased as they have been buffered) Performance improved in sodium bicarbonate condition

Answer 201

Trained already have adaptations that increase monocarboxylase transporters so already have an improved buffering capacity This effect is less in longer duration, quite similar

Answer 202

Placebo, medium 0.3g/kg, high 0/5g/kg Pre workout there was an increase in pH (more alkali), sodium incarnate conc, but no change in potassium conc from supplementation After exercise pH dropped less in supplementation, same with bicarbonate concentration Smaller elevation in potassium concentration in supplementation Greater average power in Wingate in high supplementation

Answer 203

8 week training: Both increased buffering capacity, VO2 peak, Lactate threshold But with sodium bicarbonate there was more of an increase in Lactate threshold and time to fatigue Better trained showed less of an effect

Answer 204

Nausea, vomiting, GI distress Better to take with capsules Have with fluid and light meal, spread dose, specific profiling

Answer 205

0.3-0.5g/kgBM 90-120 min per exercise Exercise where pH is limiting Individual variation

Answer 206

Dipeptide present in animal flesh L-histidie (EAA) Beta alanine (AA) Buffers hydrogen ions, when you exercise there is an increase in lactic acid which dissociates into lactate and hydrogen ions, carnosine prevents this accumulation Carnosine also acts as a antioxidant protecting against oxygen radicals Glycation and carbonisation prevention - stop glucose and protein sticking Carnitine is made in the body, but beta alanine is rate limiting in it's production 15% of our muscle buffering ability comes from carnosine More carnosine in type 2 muscles, this makes sense as explosive contractions are more likely to result in increased lactate concentration Aging decreases carnosine Males have more If you eat more beta alanine, you will have more carnosine

Answer 207

You can't absorb it whole You eat it and splits into L-histidie and beta alanine Dietary carnosine is absorbed into hepatic portal veins and splits into its parts Beta-alanine shares transport with taurine so need to make sure don't have too much in which taurine uptake is decreased Carnosine synthesase puts them back together Supplementation does just with Beta alanine supplementation

Answer 208

A total of 200g of BA must be taken 6 weeks at 4.8d/day, 9 weeks at 3.2g/day or 18 weeks at 1.6g/day

Answer 209

Training was done on weeks 0, 4, and 10. no additional training was done No changes in placebo More work done, and more carnosine in muscle done in beta alanine supplementation

Answer 210

Baseline carnosine correlates to performance Supplementation increased performance

Answer 211

Under 60 secs = no improvement 50-240 secs = biggest impact Over 240 secs = some impact

Answer 212

Placebo and beta alanine Both increased VO2 max at 3 weeks, further increase at 6 weeks in BA Both increased time to exhaustion at 3 weeks, further increase in BA at 6 weeks BA allowed the training to be at a higher intensity

Answer 213

Long washout Stable protein, so 2% per week

Answer 214

Parathesia Double vision Weight gain Hypertension Decrease in performance So can take slow release tablets

Answer 215

Taking beta alanine was the most important, but taken with sodium bicarbonate helped but wasn't significant (only 70% chance it was helping)

Answer 216

Beta alanine was more effective, and with sodium bicarbonate didn't help anymore

Answer 217

It is in the muscle, while sodium biacrobate is extracellular so its in the blood, so has to go into the muscle to work So the beta alanine is in the muscle already so can buffer straight away

Answer 218

Found that sodium bicarbonate group only was the most effective Difference was it was less duration, and was how fast you can do something not for how long

Answer 219

During exercise muscle glycogen drops During exercise GLUT4 is at membrane to take up glucose thanks to calcium and adrenaline Once exercise stops consume CHO which means the pancreas releases insulin GLUT4 to cell membrane which takes up more glucose, so there is a large amount of GLUT4 at the membrane at this point So there is a rapid rise in glycogen resynthesis (first phase, which slows down after this initial rise (second phase)

Answer 220

Glycogen synthase goes to it's active form when there is increase Insulin, Glucose, and Glucose-6-phosphate which makes Protein phosphatase which activates glycogen synthase However exercise increases the amount of calcium ions, glucagon, and adrenaline which increases protein kinase A, which converts glycogen synthase into it's inactive form

Answer 221

max rate of 1.2g/kg/h results in max muscle glycogen re synthesis rate

Answer 222

Beef = lowest insulin response Just glucose = medium response Both = best response Which increases glycogen synthase and increase glucose uptake which repsults in increased muscle glycogen synthesis

Answer 223

Same as previous study, there was the greatest increase in muscle glycogen storage

Answer 224

Glutamine alone doesn't really increase insulin But greatest rise came from glutamine with glucose polymer Glutamine alone provide the smallest muscle glycogen concentration Glutamine and glucose polymer provided medium response Glucose polymer alone provided largest muscle glycogen concentration Glutamine + glucose also resulted in largest non oxidative CHO disposal, so wasn't being used, but also wasn't being stored in the muscle, but the liver

Answer 225

That with sufficient CHO there is no need to add protein for muscle glycogen resynthesis Most likely protein only helps when Cho is suboptimal (under 1,2g/kg/h)

Answer 226

Adenosine normally binds to and adenosine receptor, and this makes you feel tired Caffeine blocks this and binds to the receptor itself , pituarity gland sees this as an issue and increases adrenaline Adrenaline stimulates hepatic glucose output, and promotes intestinal absorption More glucose in blood More glucose taken up by muscle Greater muscle glycogen synthesis

Answer 227

Carb or Carb + caffeine Not much caffeine ingested as only 71kg so reduced amount (only 1g/kg/bm) Higher glucose seen with caffeine Higher insulin AUC with caffeine So caffeine stimulates glycogen resynthesis But Beelen 2012 showed that adding caffeine or protein only works when carbs are not optimal There are also no differences in the muscle fibre types

Answer 228

Small regular feeding better than few large doses No difference if solid or liquid CHO but liquid might help rehydrate, and easier to consume when appetite is reduce You want glucose/sucrose as fructose increases it in the liver to be able to converted into glucose

Answer 229

Gastric emptying - maximise Depends on volume / energy content / osmolality / temperature / exercise / dehydration Intestinal absorption - electrolyte content Palatability - flavour / temp / electrolyte content

Answer 230

Fluid volume topped up (not too high) enhances gastric emptying Energy content. not too high (6% CHO) - higher will slow gastric emptying Same as above for osmolality Temp - no effect on gastric emptying but tastes better Dehydration - avoid below 2% weight loss - reduced splanchnic blood flow Flavour - tasty - drink more Electrolyte - tasty levels - maintains Na+ conc and thirst

Answer 231

Known that for whatever body weigh you lose from dehydration as to drink 1.5 x that weight in water Lower the urine output, the more water has stayed in the body - 100mml was the best but would have been disgusting - it also showed the best net fluid balance, they were the only ones who remained in the positive state after 6 hours 25 mmol only one you cn drink normally - 100mmol also caused issues with the potassium balance We can try get this salt from food instead

Answer 232

Protein can aid fluid retention But this not effect time to exhaustion trial

Answer 233

Hydration index for larger is slightly lower than water but not significant Beer will not complete restore fluid balance Add some sodium to the beet and its more effective Lower alcohol is better Going over 4% is problematic Claims of micronutrients - caution Not great source of calories - alcohol calories not good for muscle (can't use it)

Answer 234

Following EE there is increased muscle protein synthesis, muscle damage and loss of contractile function Protein increases muscle protein synthesis - inhibiting mTOR delays the recovery of muscle function Protein shown to enhance recovery - but not through increasing muscle protein synthesis (Pavis et al., 2020) in the exam

Answer 235

They attenuate muscle soreness - specifically 48-72hrs after eccentric exercise However no functional effect No change in Creatine kinase or myoglobin in blood Whey protein, had slight functional effect at early time points, had no effect on creatine kinase, no effect on IL6 (inflammation marker), Had an early effect on muscle soreness

Answer 236

Effect of protein with polyphenols after 300 eccentrics Soreness reduced with protein, and function recovered quicker Early on there are hue signalling changes driven by nutritional intervention - perhaps the real rational for protein being effective Don't forget polyphenols and antioxidant lecture and how they effect recovery

Answer 237

Exercise depletes them, eating CHO helps replenish Deplete carb then replenish helps performance

Answer 238

Glucose gets dragged into the cell during exercise to provide ATP After exercise is in the cell to replenish glycogen stores (insulin stimulated glucose uptake)

Answer 239

For performance we want a nutritional intervention if we are going to be performing later that day, ie carbohydrate after an endurance bout to replenish glycogen stores We want homeostasis to result in adaptation Theory on exercising in the low glycogen state to disrupt homeostasis more to result in a larger adaptation Pilegaard et al 2002 showed that there was more activation of PDK4 (means less PDC which means less glucose oxidation = harsher conditions) that result in adaptation in the low glycogen state compared to the normal following exercise, there was also more expression of UCP3 in low muscle glycogen indicating more mitochondrial expression The low glycogen state was achieved by working out only 1 leg, and not providing CHO so glycogen not restored in that leg, but the other is fine as it didn't do the workout Same in LPL, so more efficient utilising lipids Take home message is avoid carbs after training to drive larger adaptation as glycogen is not replenished Different study looked also at PGC-1 which is believed to be main determinant on mitochondria biogenesis, and low carb diet enhances this

Answer 240

In low state (Training twice every second day, so second session is in the glycogen depleted state) had higher muscle glycogen content by the end of the study, compared to training once every day (never in the glycogen depleted state and overall do the same amount of work) Better muscle oxidative capacity seen as well, as well an improvement in exercise performance But under tightly controlled laboratory conditions - not allowing for any alteration in training load dependent on nutritional status) Best nutritionists working with runners, chose specific times of year (off season) to work in low carb state to get maximal adaptation

Answer 241

Compared does having carbs allow you to do more work which outweighs the better adaptations you get from being in the low carb state High group performed better in the maximal hit sessions Low carb training group still had far better adaptations even though they did less work in the maximal hit class However there was no statistical benefit in exercise performance in low carb group Ben Wall says its due to difficulty to find top gear, they are in less of a good position to do it as they aren't use to going max out

Answer 242

Chonric low CHO diet Twice per day training Train after overnight fast Withhold CHO in early recovery Sleep low/ train low Issues: Poor training quality Immunosuppression Muscle protein loss

Answer 243

Synthesised from the amino acids arginine and glycine Synthesised in liver and kidney Muscle concentration < 160mmol.kg^-1, 60% in the phosphorylated state Meeting ATp demand during sprint exercise: PCR (increased by supplementation) + ADP + H+ with creatine kinase goes to ATP + Cr, which then the ATP is used for energy by ATPases resulting ADP + Pi + H+ In resting state = PCr, after exercise is Cr Glycogen + 3ADP + Pi via glycolysis creates 3ATP + 2 lactate + 2H+, the ATP is used by the ATPases

Answer 244

Increased {PCr} Increase capacity to perform high intensity contraction within a bout (anaerobic performance) Increased rate of PCr resyntehsis Increased capacity to perform multiple bouts of high intensity contractions Increased training adaptations as result of training load Glycogen resynthesis Aerobic permanence? H+ buffering Improved diffusion of ATP through the muscle Activation of glycolytic enzymes Main way it works is that it allows you to do more reps

Answer 245

20g or 0.3kg^-1 for 5 days Maintenance dose 2g or 0.03g.kg^-1 CHO coingestion - helps to alleviate non responders issue Good safety - don't need to cycle it Side effects - increase in water weight or body weight

Answer 246

Ibuprofen and paracetamol block MPS following exercise in young men In 2011 did not block hypertrophy in older individuals in older adults

Sports nutrition and metabolism Flashcards

(284 cards)