GhostRider62

You might have rode over the word, "Subcutaneous"


The study I linked was showing how different substrates and sources of those substrates are called upon as power and energy levels over time increase


At 50% VO2 max, fat is still being burned at a high percentage, which varies of course from individual to individual. Between 25-50%, more of the fatty acids were from intramuscular triacylglycerides. (I always wondered why top ultraendurance cyclists have less of striated muscle look to their legs and kind of a chubby look....LOL). The lipids of concern in weight loss are the subcutaneous ones.


The challenge for weight loss is being able to doe "it" day after day after week and month. In my experience, low intensity and lower carb, higher fat, and higher protein diet is sustainable although this is not something to do if racing or even trying to build. At best, it would be an off season or early season strategy, especially in the cold.


The crossover from fat to CHO listed in that study is kind of high at 65%, this transition is trainable. Some would say that is a low power because they are thinking percentage of FTP. Lets say a rider has a VO2 max of 400 watts and an FTP of 300 watts, 65% of VO2 max is 270 watts or 90% of FTP. At a more extreme level of utilization, 340w FTP (85% of VO2 max is pretty high) gives just about 80% of FTP. 80-90% of FTP is Tempo. Of course 25% at only 100 watts gives 360 calories per hour but nearly all of that would be subcutaneous fat and if we are touring or hiking, it would be a pound of fat. In one day. I have done that for weeks. That was basically the gist of my point.