Running speed is limited by a mechanical interaction between the stance and swing phases of the stride. Here, we tested whether stance phase limitations are imposed by ground force maximums or foot-ground contact time minimums. We selected one-legged hopping and backward running as experimental contrasts to forward running and had seven athletic subjects complete progressive discontinuous tread...

Selective breeding for high wheel-running activity has generated four lines of laboratory house mice (S lines) that run about 170% more than their control counterparts (C lines) on a daily basis, mostly because they run faster. We tested whether maximum aerobic metabolic rates (V(O2max)) have evolved in concert with wheel-running, using 48 females from generation 35. Voluntary activity and meta...

Abatraet-Five species of cockroach were tested on a miniature tr~dmill at three velocities as Or consumption (PO>) was measured: Gromphadorhina ~hop~rd~, Blaberus d~cojd~~is, ~ubluber~ posricus, Byrsotria fimugata and Peripluneta americana. All cockroaches showed a classical aerobic response to running: ljol increased rapidly from a resting rate to a steady-state (PO;,,): lliZ on-response varie...

Six adult white Pekin ducks were trained to run on a treadmill for 10 min at a speed of 1 -43 km h". O2 consumption, CO2 production, breathing rate, blood gas tension and pH, sciatic and carotid blood flows and colonic and skin temperatures were measured in the experiments. A 2*6 times increase in oxygen consumption was observed when going from resting on the treadmill to exercise. The increase...