10 23 13 kin 110 class notes Alanine and BCAA s enter energy paths o Glycogen glucose alanine pyruvate other BCAA s acetyl coA o Triglyceride Entry of a a can replace some of the pyruvate and acetyl CoA coming from CHO o In most situations contribution from PRO is 3 7 of total energy o What situations increase that Exercise Exercise o Use of PRO goes up o Higher intensity more it increases o Increased use of PRO is closely tied to lower amounts of muscle glycogen Sweat urea nitrogen mg hr vs experimental treatments o Estimate use of PRO from sweat Nitrogen o Race horses when loaded with carbohydrate less nitrogen o Carbohydrate depleted much more nitrogen Oxidation of leucine vs time o When CHO consumed use of PRO for energy goes down Any situation that CHO availability o Exercise esp long duration or high intensity o Fating even 10 12 hours without food Use up 50 of inner glycogen Low energy or low CHO diets o Lower availability of CHO so greater use of protein o Both diets cause rapid weight loss because of loss of protein o Pro 4 kcal g o Fat 9 kcal g How much PRO does anyone need o What do you do first Step 1 measure excretion o Assume what is excreted equals what you need to replace o PRO excretion Human volunteers o 0 protein diet o measure all sources of protein excretion o urine feces sweat dead skin other protein excretion g of PRO kg day vs days o minimal PRO excretion is 6 4 g PRO kg day o 130 lb person 24 g day o 200 lb person 36 g day whats next o Feed 6 4 g PRO kg day and see if it keeps them in balance o Doesn t work o Isn t enough because People adjust to low intake by conserving o Hair stops growing o Recycle amino acids etc Surplus balance deficit o Gram protein kg body weight per day Is this the RDA for PRO o 0 8 g PRO kg day RDA sufficient for athletes in training o Probably NOT PRO needed to increase muscle mass resistance power athletes PRO to balance the increased use when glycogen is low endurance athletes PRO for repair of muscle damage endurance power athletes What are requirements o Endurance and strength athletes 1 2 1 5 g PRO kg day o 130 lb person do athletes need protein supplements o Athletes need to eat more food Sedentary person 70 kg eats 2000 kcal day gets 15 of energy from PRO o 15 of 2000 kcal 300 kcal PRO 4 kcal g 75 grams PRO 1 05 g PRO kg day o athlete who also weighs 70 kg gets 15 OF ENERGY FROM PRO east 3000 kcal day 450 112 g PRO day 1 5 g PRO kg Bw day
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