Sport Nutrition second half

Question 1

Define micro-nutrients

Answer 1

Essential nutrients (can’t synth all that we need), required in small amounts for health

Question 2

Difference between vitamins and minerals

Answer 2

Organic micronutrients essential for a specific organism
Cannot be synth so must be obtained from the diet
Minerals
Essential inorganic micronutrients

Question 3

Which vitmains can be synthesised by the body?

Answer 3

D can be synth in skin from cholesterol with exposure to UV

Vitamin K synthesised by some gut bacteria

Question 4

Water soluble vitamins?

Answer 4

B complex (12 different vitmaines
		C

Question 5

Fat soluble vitmamins?

Answer 5

A (found in lliver, known as retinoids)

E,D,K

Question 6

Functions of vitamins

Answer 6

Energy metab

		B complex - lots of citric acid cycle components, part of NAD and B5 CoA?

	Antioxidants

		A,C,E

	Synthesis of body components

			Collagen Vit C
			Hormones Vit C (norepinephrine)
			Bone Vit D, A
			Blood clotting factors Vit K
			Visual pigment Vit A

Question 7

How many minerals, classification?

Answer 7

15 inorganic elements
	Minerals - required in amounts >100mg.day
		Ca, P, Mg, K, Fe, Na, Zn, Cl
	Trace Elements - required in <20mg.day
(others)

Question 8

Function of minerals?

Answer 8

Structure
Bone and teeth
Most abundant - Ca, P, Mg
Function
Soluble salts responsible for body fluid osmolality and determination of ICF and ECF volume
Na, K (more ICF), Cl, Mg, Ca
Maintain normal heart rhythm, muscle contractibility, neural conductivity
Regulation
Components of proteins (hormones and enzymes)
I and thryroxine
Fe, Cu, Zn components of enzymes/ cofactors

Question 9

What do antioxidants do?

Answer 9

Prevent of limit damaging effects of free radicals in the body (intra and intercellularly)
Atoms or molecules with 1 or more unpaired electron
Most common are reactive oxygen species (ROS)

Question 10

How are ROS formed?

Answer 10

Aerobic resp - intermediates in normal reactions
	WBCs-ROS for invading pathogens
	Hypoxia e.g. HIIT
	Radiation and pollution
	Smoking
	UV 
Inflammation

Question 11

Describe enzyme control of radicals e.g. O2-

Answer 11

SOD (o2 -> H2O2)
Catalase (h2O2 = H2O and O2)
Gluathione peroxidase

Question 12

Describe non-enzyme control of radicals

Answer 12

Non enzyme
Vit E - major lipid soluble antioxidant
Protects membranes from oxidative damage
Vit C
Aqueous components of body
Flavonoids and carotenoids

Question 13

Role of antioxidants in skeletal muscle fatigue?

Answer 13

Antioxidants in skeletal muscle fatigue
=Inability of muscle to generate force
Radical production may play a role
ROS increases in contracting skeletal muscle
Excessive ROS induces oxidative damage to muscle proteins and reduces force production
Mostly from animal studies - antioxidants protect skeletal muscle from damage and delay fatigue during prolonged submax exercise
No effect on high intensity

Question 14

Study that an antioxidant can prolong fatigue?

Answer 14

Exercise can be prolonged with N-acetylcysteine infusion (NAC) - antioxidant
70% VO2 max at 45 min then fatigue at 92% VO2max - time increases by miunutes
Little evidence that dietary antioxidants could make a difference e,g, E, C, betacarotene

Question 15

Arguments for Vitamin C/E supplementation?

Answer 15

Most common are not toxic so no harm
Radicals promote fatigue in skeletal msucel
NAX attenuates
Inadequate dietary intake e.g. Restriction, poor diet, increased training

Question 16

Arguments against vitamin supplementation?

Answer 16

Exercise oxidative stress -no evidence it harms health
Exercise increases antiocidants (both kinds) in skeletal muscle)
If dietary intake sufficient, supplementation likely not needed
Might impair adaptation of muscle to exercise
ROS signal to promote expression of skeletal muscle proteins
Antioxidant enzymes, mitochondiral proteins and heat shock proteins

Question 17

Explain the Golman dilemma

Answer 17

198 US olympic athletes asked 2 questions
Would they take performance enhancing drugs if,
Guarenteed to win every comp for 5 years
Guaranteed notto get caught
98% yes
Would they take performance enhancing frugs if:
Same
But guarenteed death from side effects
52% said yes
1992

Question 18

Findings from the Gooldman dilema revisited?

Answer 18

Athletes more concerned about legality than death

Question 19

What is Maughan’s rule for supplements

Answer 19

If it works, its banned
If it doesnt work, its not banned
Few exceptions

Question 20

Why do athletes supplement?

Answer 20

Aid recovery
	Health
	Improve performance
	Prevent. Treat illness.
	Compensate poor diet
Most high level take 80-90% track and field

Question 21

Why may an athlete have a poor diet and need supplements?

Answer 21

If eliminated food group e.g. Vegan
If put into energy deficit - may need supplements
Need extra valories/ carbs

Question 22

Why is taking lots of supps potentially detrimental?

Answer 22

Risk of contamination increases

Potential detriment to performance

Question 23

describe types of nutritional supplements

Answer 23

Ergogenic
	Ergo=work
	Genic=making
		Creatine - from meat, veges better
		Beta-alanine/carnosine - only is turkey (eat lots for sufficient amount)
		Biocarbonate
		Caffeine? - some from foods
		Nitrate? - some foods e.g. beetroot
Sports food
	Protein
Carb - tablets, drinks

Question 24

which group may benefit from creatine supps the most?

Answer 24

Females

Question 25

In 2008 how many sipplements contained WADA banned steroids or prohormones?

Answer 25

14.8%

Question 26

How do banned supps get into legal supps?

Answer 26

Often raw materials cross contaminated at source Manufacturing process cross contamination of line Outsorced manufacturer Inadequate cleaning of machinery Not because they want their product to better

Question 27

How sesnitive are anti doping tests in 2009?

Answer 27

0.00005% can detect 2.5ug 25% would fail 5ug 50% would fail -level has been found

Question 28

How can a practicitioner know if a supp is clean? drawbacks?

Answer 28

informed-sport.com logo Means batch has been tested Often on site but not always on product

Question 29

How much and why for muscle biopsy

Answer 29

.1g | Used for glycogen, protein synthesis

Question 30

3 questions to ask when considering supplements?

Answer 30

Is there an underpinning biological rationale? If i was to provide this, does it reach desired location? Does it change plasma conc? If it reaches muscle, is it taken up and does it change anything?

Question 31

Difference between rates of ATP turnover and physiological mechanism for this

Answer 31

In cells with low rate of ATP turnover e.g. Skin cell and plant cell ATP produced in mito, travells to muscle, used to fuel muscle contraction/ biological process In cells with high rate of ATP turnover e.g. Muscle and brain ATP synesised, dephosphorylates and phosphate transferead to Cr (creatine) Creating phosphate suttles across to site of biological process/ muscle, Forms ATP. Acts as a shuttle.

Question 32

Describe the biological roles of creatine

Answer 32

Plays a role in resynthesis of ATP from ADP 1) Directly rephosphorylate ADP to form ATP 2) Shuttle phosphates from site where nutriets are synthesised e.g. Mito to muscle (H+ role)

Question 33

describe variation in creatine loading

Answer 33

Different starting points for total creatinine Start from a lower level, see a bigger increase (ceiling effect) Some people with higher levels don't really change Vegetarians maybe have lower creatine

Question 34

Normal loading dose and maintainence of cretine

Answer 34

5x4/day one week | followed by 2g/day

Question 35

Hultman et al 1996 methods

Answer 35

Active males 4 groups 1- 20 for 6, muscle biopsies at day 0,7,21 and 35 2- 20 for 6 then 2 for 28, 0,7,21,35 3- 3 for 28days, days 0,15,29 4- 20g of placebo for 5 days, 24h urine sample multiple times until (day 25 after). Same subjects then injgested placebo and Cr for 5 days (same as 6). (24 hr).

Question 36

Hultman et al 1996 key findings

Answer 36

Muscle total creatine conc increased by 20% after 6 days of supp at a rate of 20g/day Maintain if supp continued at 2g/day for a further 30 days Without, total creatine gradually decline over next 30 days until there there was no diff to presupp value Correspondingly urine increased with increased creatine up to day 5, decline afterwards compared woth placebo More gradual increas if 3g/day supp over 28 days Conc 20g a day for 6 days= rapid creatine load 3g a day, same effect in long term

Question 37

Hultman et al 1996 main aim

Answer 37

The effect of dietary creatine supplementation on skeletal muscle creatine accumulation and subsequent degradation and on urinary creatinine

Question 38

Sale et al 2009 main aim

Answer 38

to compare the effect of two creatine monohydrate supplementation regimes (4x5 g day and 20 x1 g day for 5 days) on urinary creatine and methylamine excretion. (methylamine = potential toxic compound)

Question 39

Sale et al 2009 methods

Answer 39

9 males each completing 2 trials separated by 9 weeks 1- 4x5xday for 5 days 2-20x1xday for 5 days Collected 24h urine days 1-2 (baseline) and day 5 and 2 post supp days (days 8-9) Urine assayed for creatine and methylamine

Question 40

Sale et al 2009 key findings

Answer 40

Less creatine and methylamine excreted following the 20x1gxday regime Suggests a greater retention in body and likely in the muscle. Lower and more frequent doses of creatine monohydrate attenuate formation of methylamine

Question 41

Green et al 1996 aim

Answer 41

The effect of carb ingestion on skeletal muscle Cr accumulation during Cr supplementation in human

Question 42

Green et al 1996 method

Answer 42

Muscle biopsy, urine, plasma from males before and after ingestion of: 1) 5g Cr 2) 5g CR, followed by CHO30 mins later 4x a day for 5 days

Question 43

Green et al 1996 key findings

Answer 43

Supplementation resulted in an increase in muscle PCr,Cr and TCr in both groups. 60% greater TCr in group B. Corresponding decrease in urinary Cr excretion in group B Cr had no effect on insulin conc but Cr and CHO did. Suggests Cr accumulation may be insulin mediated.

Question 44

Effect of exercise on creating conc

Answer 44

Increased retention of creatine postex, at 6h and 5day in ex leg compared with non ex leg

Question 45

Effect of creatine on glycogen stores

Answer 45

Slight increase found p=0.06 with exercise

Question 46

Casey et al 1996 aim

Answer 46

to perform a direct investigation of the effects of Cr supplementation on skeletal muscle energy metabolism and performance during repeated bouts of maximal exercise in humans.

Question 47

Casey et al 1996 methods

Answer 47

2x 30s maximal isokinetic cycling separated by 4 mins of passive recovery befor and after ingestion of 20g Cr monohydrate/day for 5 days Muscle biopsies were taken before and after each session of 2 bouts (pre and post Cr) Measured total work production and peak work production

Question 48

Casey et al 1996 key finidngs

Answer 48

Increase in TCr conc in muscle Total work production increased during both bouts Cumulative increases in both peak and total work production over the 2 bouts were correlated with increase in muscle TCr Culumative loss of ATP was less after Cr ingestion despite increased work production Resting PCR increased in type 1&2 fibres, correlated with changes in total work production and PCR breakdown. Suggests an improvement in ATP resynthesis due to increased PCr availability

Question 49

Rawson et al 2011 aim

Answer 49

Examine the effects of 6wk of low-dose creatine supp on body comp, muscle function and body creatine retention

Question 50

Rawson et al 2011 methods

Answer 50

1) Creatine 0.03g/lg/day 2) Placebo 6 week, double blind trial Tested before and after supplementation Included Body composition - electrode bioimpedance analyzer Maximal strength (3-rep max concentric knee extension at 180deg) Muscle fatigue (5 sets of 30 concentric knee ex..) Plasma creatine conc

Question 51

Rawson et al 2011 key findings

Answer 51

No sig diff in body mass, FFM, FM, total body water or maximal strength in either group. Plasma creatine increased in creatine group, no diff in placebo Creatine group more resitent to fatigue during sets 2-5

Question 52

Describe exercise and pH

Answer 52

Everytime ATP is resynthesised | H+ is produced from glycogolysis, either lactate and H+ or CO2 (more from HI)

Question 53

Describe the body's mechanism for H+ buffering

Answer 53

Slows decline in pH Buffer at muscle and in blood stream Physico-chemical buffering in the muscle e.g. Phosphate, bicarbonate, petide/protein bound histidine Dynamic buffering - with sodium bicarbonate in the circulation from diffused H+

Question 54

Describe creatine and buffering

Answer 54

CK reaction results in the breakdown of PCr and the regeneration of ATP H+ is consumed as part of the process PCr breakdown during high-intensity exercise could contribute to intracellular buffering Might have a small effect on muscle buffering capactiy as well as ATP regen

Question 55

How is carnosine normally synthesised?

Answer 55

Increases muscle carnosine Histidine+ B alanine = carnosine Histidine already high, increase B-alanine which may be lmiting step here Consume carnosine in diet, broken down into b alanine and hisitidine

Question 56

Harris et al 2006 aims

Answer 56

x

Question 57

Harris et al 2006 methods

Answer 57

x

Question 58

Harris et al 2006 key findings

Answer 58

x

Question 59

MoA of beta alanine?

Answer 59

Forms more carnosine, acts as pH buffer, delaying fatigue in high intensity exercise

Question 60

Hill et al 2007 aim

Answer 60

Influence of b-alanine supplementation on skeletal muscle carnosine concentrations and high intensity cycling capacity

Question 61

Hill et al 2007 methods

Answer 61

``` 4weeks or 10weeks BA Biopsy of VL at 0,4,10 wks. Cycle capacity test (CCT) to determine (TWD) at 110% of max power Matched subjects receiving placebo Completed CCT at 0,4,8.10 weeks ```

Question 62

Hill et al 2007 key findings

Answer 62

Muscle carnosine increased at both 4 and further increase at 10wks BA supp Carnosine increased equally in type 1,2 over 10 weeks No increase in control BA supp resulted in increase TWD at 4 and further increase at 10 weeks This was associated with increase in muscle carnosine Taurine unchanged in both groups

Question 63

Benefit of BA on exercise lasting <60s? when is optimal?

Answer 63

No benefit on exercise lasting <60s | Beetter for 1-4 mins (more H where buffering is more useful)