Continuous (A, B) versus intermittent (C) training in CantonS flies. Performance index (PI) includes 30-sec pretest (black bars), training (densely hatched bars, 2 min each), intermittent test phases (only in C, empty bars, each 1 min), and final test (broadly hatched bars, 3 min). Error bars are SEMs; n indicates number of flies; *P < 0.05, **P < 0.01, ***P < 0.001, as in all subsequent figures.