kale sports nutrition

storage form of carbohydrates

glycogen

sources of carbs during exercise and when are they used

what happens at glycogen depletion?

1. exercise <30mins: muscle glycogen

2. hepatic glycogen

3. blood glucose

glycogen depletion: exercise is at 50% maximal capacity

carbohydrates are _________% of total energy intake

55-70%

t/f: heavy exercise is a glycogen mediated process

true, significant use by 60-120min. light exercise does not rlly deplete glycogen

recommended dietary allowance for protein

0.8g/kg/day

there are higher requirements for protein in illness, elderly, and pregnancy. what is the max recommended dose?

3g/kg/day

what is the primary energy source for prolonged low to moderate intensity exercise

lipids

lipids represent _____ of total caloric intake

10-35%

t/f: individuals at a higher fitness level are more likely to utilize fat over glycogen

true

what macronutrient does the body prefer according to exercise intensity level

low levels-> lipids

high-> glycogen (carbs)

highest-> anaerobic metabolism, creatine phosphate, ATP

describe the relative amount of glycogen that would be depleted in a low intensity long distance run compared to a high intensity run

- long time low intensity is glycogen sparing

- high intensity runs would use up more glycogen (1 hr run typically wouldnt use up all of glycogen)

t/f: dietary supplements are not subject to FDA regulation

true. they only step in AFTER product is available

what did Dietary Supplement Health and Education Act (DHSEA) establish regarding dietary supplements

- manufacturers are responsible before taking a product to market

- FDA is responsible AFTER the product has reached the market (if a problem were to occur)

misbranding

- unlabeled ingredients

- ingredients in quantities other than what is stated

what does USP do

United States Pharmacopeia-> sets standard for drug quality and related practices but don't enforce anything

- supplements can claim USP compliance (optional)

why do most supplements avoid claiming USP compliance

- must abide by USP standards. if they dont then they may be deemed as misbranded

the Academy recommends ______g of carbs per hour of exercise over 60 minutes

30-60g

(ex: gels, drinks, meal bars)

(typical snack is about 15-30g)

what does the Academy recommend for carb intake for an individual on a moderate exercise program

5-7grams/kg/day

moderate exercise= 1hr per day

what does the Academy recommend for carb intake for an individual on a high intensity exercise program

6-10g/kg/day

high exercise= 1-3hrs per day

exercise less than ____ minutes do not require carb refueling

45 minutes

exercise over ______ hour requires carb replenishment

1 hour

what is the max amount of carb replenishment for ultra endurance

90g/hr

if sports drinks have 6-8% of carbs, what does this mean in terms of ml?

6-8% means 6-8g per 100ml

forms of carb replenishments

- sports drinks

- gel packets (higher carb content, needs water)

- energy bars (requires water, good for post exercise)

long chain vs medium chain fats (summary)

long chain (>12C)

absorption: lymph (slow)

effects: slow Gi transit, may cause GI upset [consume 1-2hrs before exercise]

medium chain:

absorption: blood circulation; active within 30mins

effects: reduce glycogen use, found in sports products, more favorable for GI

>______hrs of exercise per week generally requires more protein

10 hours

how much protein is recommended for highly active adults or those increasing body mass

1.2-2.0 grams/kg/day

t/f: there is insufficient evidence to recommend packaged protein products by the Academy

true. eat well balanced meal instead

how much recovery protein (following exercise) does the Academy suggest

50-100 grams during recovery period

what does data suggest about increased intake of protein (>2g/kg) and harm

inconclusive.

may cause GI distress, hypertension, renal or hepatic injury

what is recommened regarding pre-exercise hydration

1. establish normal body water: 5-10ml/kg within 2-4hrs of exercise

2. eat a meal to promote hydration via water retention several hrs before

t/f: sports drinks have been proven to be superior hydrators when compared to a meal + hydration

false.

what can excessive water without electrolytes lead to

hyponatremia (low sodium)

hyponatremia

deficient sodium in the blood

what are the types of sports drinks available and what are their benefits

1. electrolytes + water

- no big benefit, mayyy increase water absorption

2. electrolytes+ carbs + water

- good for exercise over 1hr

- 500-1000ml/hr needed for 30-60g/hr

3. electrolytes + carbs + protein + water

- some benefits in extreme

- Gi intolerance concerns

post-exercise nutrition and recovery goals

rehydrate, restore muscle glycogen, repair muscle damage

-> Academy suggests to consume a balanced meal/snack

ergogenic aids

any nutritional, physical, mechanical, psychological, or pharmacological procedure or aid used to improve athletic performance

-> considered ergogenic if studies show enhancement after weeks/months of use

caffeine mech and effects (pros)

adenosine antagonist promoting calcium release

-> increases alertness, reduces fatigue perception, longer exercise output/intensity

normal dose range for caffeine

3-9mg/kg

caffeine cons

- tremor, anxiety, increased HR

- can be toxic in high doses

- banned if certain levels exceeded

- may lead to dehydration (diuresis)

diuresis

what is it?

what causes it (caffeine)?

increased formation and secretion of urine

-> brought by adenosine blockade and natriuresis (caffeine)

-> phosphodiesterase inhibition (proximal tubule)

-> inhibits sodium reabsorption, increases solute + free water excretion

what is creatine

naturally occurring non-protein amino acid that helps muscle w energy (95% of endogenous is stored in muscle tissue)

- interacts with phosphagens to increase ATP availability

natural sources of creatine

red meat, fish, endogenous synthesis

pros and cons of creatine

pros:

- increased muscle mass

- improve exercise capacity

- greater training adaptation and muscle hypertrophy

cons:

- acute weight gain

- GI discomfort

APPARENTLY EFFECTIVE, GENERALLY SAFE

beta hydroxy beta methylbutyrate (HMB)

5 carbon derivative of leucine (essential amino acid)

- plays a role in protein metabolism and synthesis

- may regenerate damaged tissue

beta hydroxy beta methylbutyrate (HMB) pros and cons

pros:

- increase muscle mass

- increase strength

- decreased catabolic effects

- appears safe in 3-6 grams daily

cons:

no significant adverse effects noted

POSSIBLY EFFECTIVE, GENERALLY SAFE

DHEA (dehydroepiandrosterone)

weakly androgenic compound; converted to potent androgens within tissues (testosterone)

- endogenous production decreases w age

DHEA pros and cons

pros:

- maintain DHA availability (especially if aging)

- maintain/increase testosterone

- reduce body fat accumulation

cons:

- mixed results regarding body comp

- minimal support for weight loss

EFFICACY/SAFETY IS UNDETERMINED