Lecture 8 - Supplementation Flashcards
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