Intermittent locomotion increases endurance in a gecko

Nocturnal geckos can actively forage at low temperatures. A low minimum cos t of locomotion allows greater sustainable speeds by partially offsetting t he decrease in maximal oxygen consumption (Vo(2max)) associated with low no cturnal temperatures. The nocturnality hypothesis (Autumn et al. 1997) prop oses that the reduced cost of continuous locomotion is a shared, derived ch aracteristic that increases the capacity to sustain locomotion at low tempe ratures. Yet many lizards move intermittently at speeds exceeding those tha t elicit Vo(2max). We exercised the frog-eyed gecko, Teratoscincus przewals kii, continuously and intermittently on a treadmill. At an exercise speed o f 0.90 km h(-1) (270% maximum aerobic speed), lizards alternating a 15-s ex ercise period with a 30-s pause period exhibited a 1.7-fold increase in dis tance capacity (total distance traveled before fatigue) compared with lizar ds exercised continuously at the same average speed (0.30 km h(-1)). The av erage aerobic cost of intermittent exercise was not significantly different from Vo(2max). Locomoting intermittently could augment the increase in end urance resulting from the low minimum cost of continuous locomotion in noct urnal geckos. Intermittent behavior could increase the endurance of lizard movement in general.