5 februari 2013 kl 23:19
När det gäller mängden glykogen och "tidsfönstret" efter träningen som man har nytta av kolhydrattillförsel så har jag letat lite siffror och brytpunkter. Det är ju förstås som så att längden på pass samt energiuttaget utgör en faktor även här och tidsfönstret verkar kunna vara mycket längre (än vad jag själv trott). En av anledningarna till att få i sig det "snabbt" är dels att bryta den katabola fasen och frigöra hormonerna som styr inlagringen av glykogen men själva processen tar mycket längre tid i anspråk.
Ett litet klipp:
"Though most of the evidence presented on glycogen is related to prolonged aerobic exercise, there is evidence that exercise mode may play a role in glycogen replenishment, with eccentric exercise exhibiting significantly longer recovery periods, up to four days post-exercise. Muscle fiber type is another factor implicated in the replenishment of glycogen in athletes, due to the enzymatic capacity of the muscle fiber, with red fiber appearing to be subjected to a greater depletion, but also undergoing repletion at a significantly grater rate.
Though early literature appeared to indicate that the time course of glycogen replenishment after exercise-induced depletion was 48 hours or more, more recent data have controverted this thought. One study reported that a carbohydrate intake totaling up to 550-625 grams per day was found to restore muscle glycogen stores to pre-exercise levels within the 22 hours between exercise sessions. The findings of this study were supported by second study in which a carbohydrate intake of 3100 kcal resulted in complete resynthesis of glycogen within 24 hours.
There also appears to be a two-hour optimal window immediately after the cessation of exercise for the administration of carbohydrates. Simple carbohydrates appear to be the preferred replacement during this replenishment period.
Normally, 2% of glycogen is resynthesized per hour after the initial 2 hours immediately after exercise. With administration of 50 grams of carbohydrate every 2 hours, the rate rose to 5% per hour, but did not rise when additional carbohydrate was administered. Administration of .7grams per kg body weight every two hours is another strategy that appears to maximize the rate of glycogen resynthesis. There is also some evidence that even smaller loads (28 grams every 15 minutes) may induce even greater repletion rates.
Therefore, at least 20 hours are required to recover muscle glycogen stores, even when the diet is optimal. So, athletes working out two times per day should complete one workout at a diminished workload to relieve the reliance on glycogen reserves.
The principle of glycogen resynthesis and supercompensation has great practical implications, not only in athletics, but also within industry for workers who consistently undergo depletion of glycogen stores due to prolonged bouts of exertion, or extended lifting tasks which would be glycolytic in nature; due to the duration, and also the myofibrillar ischemia induced by static contractions."
Enligt samma källa så verkar det som att just glykogen inlagrat i levern spelar en större roll i glykogenutmattningssammanhanget än glykogenet lagrat i musklerna och att träna "för hårt" med många pass i veckan utan att fylla på glykogenet i levern slår hårt på den fysiska arbetsförmågan.
