ENTRAINED BREATHING AND OXYGEN-CONSUMPTION DURING TREADMILL WALKING

Entrainment of the breathing rhythm to that of the rhythm of limb move ment during exercise has been shown to decrease oxygen consumption for cycling at a moderate workload. This study examined the effect of ent rainment on oxygen consumption during treadmill walking at two workloa ds. For each workload, 8 subjects performed two exercise protocols con sisting of walking on a treadmill for 8 min. For the first protocol th ey received no instructions, but for the second protocol they were ins tructed to coordinate one breath per auditory cue which was provided d uring the last 4 min of exercise. The auditory cue was transmitted as a click via headphones. It was derived from afoot switch and was desig ned to synchronize breathing to the walking pace al a respiratory freq uency close to that observed in the first protocol. Entrainment and ox ygen consumption were compared between the protocols for the last 4-mi n segments for each workload. These comparisons showed that the presen ce of the auditory cue significantly increased entrainment from 29 to 74%, but oxygen consumption was not significantly changed.