Aerobic fitness: one minute of all out effort = 45 min. of moderate effort

Reynolds has written a series of articles describing experiments showing the benefits of high-intensity interval training. She now points to a study by Gillen et al. showing that high intensity effort periods of only 1 minute can have a big effect. Twelve weeks of a regime of 3 cycling sessions per week lasting 10 minutes each, with only one minute of that time being strenuous, caused the same 20% increase in aerobic fitness as sessions of 45 min of cycling at a moderate pace.