I never cease to be amazed at how really simple questions can become almost impossible to answer when it comes to exercise physiology. I'm just an IT spod who has a passion for training and riding my bike. But, having bonked really badly on Etape 07 (or possibly underestimated the effect of altitude) I am determined to get it right for La Marmotte this year. The chart above is intended to show the percentage of fuel that is derived from muscle glycogen versus fatty acids (etc) at differing exercise intensities. Basically, at higher intensities the energy derived from glycogen becomes greater and will need to be replaced on the go. By contrast, the energy derived from fatty acids will not. Tipping Points and Sailing Close to the wind Based upon the assumption that (a) I will carbo load before La Marmotte and will have approximately 1000 cals worth of glycogen sitting in my legs and (b) I will take on 400cals of glycogen per hour then the following table tells me how many hours I can...
Follow the exploits of a fifty-something trying to beat father time by setting ambitious goals and striving to achieve them ...