How the Pros Do It
These results of Dr. Gibala’s study should not be taken as an indication that you should perform carb-fasted workouts every day. Like most exercise science studies, this one has limited relevance to the real world. First of all, the subjects were nonathletes who had a low level of initial fitness. Other research suggests that well-trained endurance athletes do not benefit as much from carb-fasted workouts. Additionally, with its lack of variation and progression and its heavy emphasis on intervals, the training protocol used in this study was very different from the way most triathletes train.
There are also physiological reasons not to get too carried away with carb-fasted workouts. Research by David Nieman at Appalachian State University has shown that