Lecture 8 - Supplementation Flashcards
(32 cards)
list some reasons as to why athletes believe that supplements are needed?
- their diets are subpar and this can fix it
- supplements are more effective than diet
- their diet is unbalanced anyways so they need to compensate
- athletes need to use supplements to get an advantage
- i.e. maintain health, promote tissue growth and repair/injury management, improve recovery and sleep
what are some major things that we should consider before taking supplements
- the use of supplements will not compensate for poor food choices and an inadequate diet
- athletes contemplating using should consider their efficacy and risk to health and performance (positive dopnig test, over supp can have health risks, supplements aren’t regulated
are nutrition supplements regulated
NO
- there is no strict regulation in testing, advertising, and promoting nutritional supplements
define a dietary supplement
vitamins, minerals, herbs, and botanicals, AAs and other dietary substances intended to supplement the diet by increasing the total dietary intake… or as any concentrate, metabolite, constituent, or combination of these ingredients
why must be critically evaluate/analyze supplement studies
with the lack of regulation, we have to see if studies actually work
- animal vs human trials (skewed results)
- were external variables controlled, was the placebo controlled (i.e. does the participant smoke
- were the trials randomized
- peer reviewed
inportant questions to ask about a supplement (specific context with an athlete)
- have several studies supported its use and an ergogenicc aid
- what intensity and mode of exercise was used (does it match with their sport)
- were participants athletes, well trained, untrained?
- what is the effective doese
- what are the side effects
List some supplements that have been proven to “work”
to “work” means that they work under certain conditions (helps do X with resistance training)
- protein (whey, soy, collagen)
- beetroot juice
- beta alanine
- caffeine
- caritine
- creatine
- sodium bicarbonate
- sodium nitrate
THE LIST OF SUPPLEMENTS THAT DON’T WORK IS MUCH LARGER
what is buffering capacity and why is it important for exercise
when maximal exercise occur, anaerobic glycolysis produces lactic acid as a byproduct. This can increase muscle acidity and effect performance in events lasting 1-10 minutes (LA causes fatigue)
- reducing muscle acidity by increasing the buffering (intra or extracellular) are theoretically ways f impriving performance in events where anaerobic glycolysis is an important contributor to ATP resynthesis
beetroot juice and sodium nitrate (NaNO3)
- beetroot juice is a good source of dietary nitrate (NO3), which can improve endurance performance in some circumstances
- effective does is 6-8mmol of nitrate or 500mg or 7mg/kg/bw
- however, natural sources of dieaty NO3, such as beetroot juice, are preferred as an ergogenic supplement for endurance athletes and game players as they are at less risk of overdosing
- better to consume in the days previous
Beta-Alanie and Carnosine
- carnosine is an intracellular buffer of H of skeletal muscles, is responsible for ~10% of total buffer capacity
- carnosine is broken down in the GI track so it doesn’t mean that you’re nessesarily absorbing it all through carnosine suppl.
- carnosine is synthesized from it’s precursors L histidine and B alanine in the liver and is taken up by the muscles, is present in the cytoplasm
when should you take B alanine and carnosine
over 4-10 weeks 3-6g a day of BA will result in a 60-80$ inc in mucsle carnosine content
- this is associated with improved perforamnce in exercise where rates of glycolysis are high (80-100% VO2 max in trained and untrained ppl)
* large acute doeses of BA appear to induce mild pseudoallergic skin reactions of paresthesia (mild flushing or tingling sensations) that dissapate within about 2hrs
- for this reason, the daily dose is usually administered as 4-8 small doses, or as a sustained slow release tablet
how can sodium bicarbonate (NaHCO3) improve performance
- NaHCO3 injenstions can improve extra cellular buffering capacity
- in increases plasma bicarbonate conc. and improved H removal from muscle, decreasing acidity and fatigue (consider LA)
daily dose of NaHCO3
- 200mg/kg/bw of sodium bicarbonate ingested 1-2hrs before exercise seems to improve performance in most studies involving HI exercise lasting 1-10mins
- optimal does seems to be 300mg/kg/bw
- at this dose, some athletes experience some GI discomfort (side effects are dose dependant; drinking large amounts of water can help)
sodium citrate
works similarly o NaHCO3, increases buffering capacity of extracellular space in increase the efflux of H ions in the intracellular space
- sodium citrate is effective in limiting the decrease in blood pH and improving endurance exercise performance up to 10mins in duration (strong evidence) or HI exercise performance of 2-4 min duration (weak evidence
typical dose of sodium citrate
300-500mg per kg of BW
what is HMB
beta-hydroxy beta methylbutyrate
- HMB is a metabolite of the essencial AA leucine and in synthesized in the body at a rate of 0.2 to 0.4g/day
- HMB seems to reduce the preakdown of protein throgugh inhibiting proteolytic pathways to stimulate protein synthesis through the stimulation of mTOR
HMB research and dose
- some studies say that it can result in increased lean body mass and muscle strength, but equal amounts of studies say no effect
- some studies indicate 1.5 to 3g of HMB increase muscle mass and strenght more than placebo in response to 3-8 wks of resistance training
- most studies have used 3g where most HMB products have very little amounts in them
- no negative reaction on organ function, emotional perception or GI tolerance
relate caffein ingestion to sport performance
- consuming the same od of caffeine in 2 cups of coffee (300mg) has a similar ergogenic effect to pure cafeine in tablet for
- it is readily absorbed after ingestion
- blood levels rise and peak after approx 60mins and half life is reported to be between 2 and 10hrs (therefore should be ingested ~1hr before exercise
caffeines main mode of action and some of its side effects
- caffeine improves cognitive function when tired,
- its main mode of action is as a CNS stimulant
- side effects include GI distress, headaches, tachycardia and restlessness
describes cafeine’s affect o different intensities and its dose
- 3-9mg/kg/bw has an ergogenic effect in endurance exercise (1-2hrs) and exercise around 100% of VO2max lasting approximately 1-5 mins
- at exercise intensities of about 85%, improvements of 10-20% in time of exhaustion has been found
- in jan 1st, 2024, international olympic committee took caffeine off its list of banned substances
carnitine
synthesized in liver and kidney, which contain 1.6% of the hole body carnitine stores, other 98% is in skeletal and heart muscle
- primary function of L carnitine is to transport long chain fatty acids into the mitochondria, where they are oxidized
- plays an inportant role in maintinging the acetyl CoA: CoA ratio in the cell
- found in large amounts in meat and dairy
carnitine’s effects on athletes
early studies using direct measurements in muslce after 14 days on 4-6mg/day of carnitine failed to show any increases in the muscle carnitine concentration, and did not improve performance
- no adverse side effects have been reported with does of up to 10g per day
creatine monohydrate
- oral creatine supp. of 20mg/day for 5 days increases muscle creatine concentration in men by around 20% (30-40% of the increase is phosphocreatine)
- a subsequent daily does of 2g is enough to mantain this concentration (diet and oralingestion together provides approx 2g per day of creatine)
- this quantitity allows an increase in the amount of work performed during single and repeated bouts of short term, high intensity exercise by may also result in some weight gain from water retention
adverse side effects of creatine monohydrate
- no studies have reported detrimental health effects of creatine
- however, according to many anecdotal reports, creatine supp may cause some GI, cardiovascular, and muscular problems, naseau, vomiting, diarrhea; alterations in kidney and liver function; muscle cramps; elevated BP
- therefore recommended doses should not be exceeded
