Fig. 4. Correlations between measures of maximum power output at 6 Hz and fatigue-resistance of the peroneus muscle at 2 Hz for 18 juvenile Xenopus laevis. There was a significant negative correlation between maximum instantaneous power output and fatigue-resistance of force (% of maximum force at cycle 30) (A). `Cycles to 5% of maximum power' is the number of cycles taken to reduce net power to 5% of the initial value at cycle 1. NS, non-significant Pearson's product moment correlation.