Fig. 3.

Metabolic modes in subjects on exercise bike. a The oxygen expenditure, oxygen consumed (VO2) in ml per min per watt produced (W), is higher at high work rates for subjects (N = 21) on an exercise bike, as calculated from published data⁴⁰. b This was reproduced for the n = 5 subjects studied in this work. c The VO2 when the derivate increases for each subject was consistently calculate to ~40% of the maximum O₂ flux. Statistics were calculated using two-sided Mann–Whitney U test. The box plot indicates data between the 25th and 75th percentiles, the central mark indicates the median and whiskers extend to the most extreme data point within 1.5 × interquartile range