Fig. 2. A sample recording of uncorrected (A) and corrected (B) P_O2 (solid line) plotted against time. The dotted lines are linear regressions applied to the decline in P_O2 before and during stimulation (B). The cumulative work (open circles) plotted against time for a rainbow trout ventricular preparation is also shown in B. This muscle was subjected to 300 work loops (5 min) at 1.0 Hz. Starting length (L₀) was 95 % L_max, where L_max is the length for maximum isometric force production, strain was ±8 % L₀ (16 % peak-to-peak) and phase of stimulation (circles on work loops) was 30°. Representative work loops from cycles 10, 50, 100, 200 and 300 are also illustrated (C). The loops are counterclockwise, with their area representing net work. Arrows indicate the direction of travel and the stimulus timing is indicated by a filled circle.