(a) The mean rate of ATP (mmol min−1) production from NEFA oxidation (ATPNEFA) during 60 min of exercise following administration of Gx or P at 0 min. The upper inset panel shows the mean (−s.d.) within-subject difference owing to treatment at each of the time points. Values recorded at 5 and 15 min have been omitted for reasons of clarity. The difference between treatments at 20 and 50 min was significant (P<0.05). (b) The mean total ATPNEFA (mol) produced by the end of each period of exercise. The mean difference (−s.d.) between treatments in total ATPNEFA is shown in the lower inset panel. The effect of treatment was just outside significance from 30 min onwards (0.06<P 0.08). Values at 5 and 15 min are again not shown, although the rates at these times were used when calculating the total produced by the end of 10 and 20 min, respectively.