9.25.13 Kin 110 class notes- Glycogen comes from muscle and from the blood glucose that comes from the glycogen in the livero Glucose pyruvate lactate & 2 ATPo or carbon dioxide and water and 36 ATP- How much CHO do athletes/people need?- Americans eat 50% of energy as CHO.o Eat 2400 kcal/day = 1200 kcal CHO CHO = 300 go Major health organizations: 50-55%- What about athletes?o Most sports nutritionists suggest that 60% of daily calories come from CHOo Carbs should be 60% of diet – sugars and starches- What do you need it for?o Brain/nerve cells need 75 g/dayo Other use= 125- 150 g/dayo Total = about 200 – 225 grams- Exercise CHO use:o 30 min easy walking = 25 g CHOo 45 min moderate running = 75o 60 min hard running = 125-150- If 60% is good, is more beter?o Does eating more CHO increase muscle glycogen?o If you increase glycogen, does better performance- Most common study of CHO and glycogeno Cross country runnerso One group 40% CHO – moderate CHO dieto Other group 70% CHO calories – high CHO diet- Muscle glycogen (mmol/kg ww) vs. timeo 8 muscle biopsies –twice a day for 4 dayso moderate in yellowo high in redo both start at the same place go for a run and both end at same placeo next days, the high carb diet is more successful in recovering/replacing glycogeno lower carb diet has low glycogen by the end of the 3 ½ days- 40% group could not replenish their glycogen between runso runners with low glycogen still completed every run – managed to run every day- Question of the Dayo Assuming that… 1. Cho is main source of energy 2. Cho is stored as muscle glycogen 3. higher levels of glycogen lead to better performance- All other things being equalo If you takeo Same person, training, task, conditionso They should perform better with more glycogen- Research in 1970’so Endurance performance improved if you started with more glycogeno Called glycogen super compensation “loading”- Depletion/repletiono A. 7 days before competition: Deplete glycogeno B. 3 day of very low CHO dieto C. In last 4 days, reduce training by 50% Really high CHO diet (>70% of kcals)- Muscle glycogen stores can be increased by 300-450 g- Modified dieto Skip depletiono 7 days before comp. cut back on trainingo while increasing CHO in diet (70% or more)o rise in glycogen not as dramatic but 15-20%, 308 grams -350 grams- big increase in glycogen should lead to better performance…o side effects… storing glycogen leads to water storage some athletes feel tightness, spongy. Weight gain- downside to increasing glycogeno use of glycogen partly depends on how much you have- so increasing glycogen stores comes with a coseo improvement in performance depends on increasing storage and how much you raise rate of useo if you store 20% more but use it 20% faster, no
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