Physiologic Responses to Treadmill and Water Running.

In brief: The physiologic responses to running on a treadmill and to running in water while wearing a buoyant vest were compared in seven uninjured runners. Ventilation, oxygen uptake, and respiratory quotient were significantly higher during treadmill running, whereas heart rate and perceived exertion were not significantly different for the two forms of exercise. Water running elicited a 36% lower metabolic cost than treadmill running despite the athletes' efforts to maintain a similar level of exertion. The results suggest that water running may help lessen the rate of deconditioning of injured athletes who must suspend their regular forms of exercise, but they fail to show that the metabolic cost of water running is significantly greater than that of treadmill running.