Physiological Responses to Standardised Arm Work

Abstract

The physiological responses of 8 healthy male subjects were studied during one- and two-arm cranking exercise performed on a suitably modified bicycle ergometer under carefully standardised conditions utilising a shoulder restraining board and harness designed to restrict trunk movement.

'Apparent ’ mechanical efficiency (E—defined as the ratio of work performed to aerobic energy expended) was found to be similar at low levels of exercise to that previously found for leg work, namely 0.25; although there was a fall in E at levels in excess of ∼40% [Vdot]_{o 2}, max- [Vdot]_E was higher in arm work than in leg work for a given [Vdot]_{o 2} or [Vdot]_{co 2},: [Qdot], however remained the same for a given [Vdot]_{o 2},, although stroke volume was reduced and cardiac frequency increased in arm work when compared with leg work.

The maximum aerobic power of the arms was found to be i that of the logs, but for a given limb volume (muscle plus bone—measured after the method of Jones and Pearson (1909)) was ∼ 13% higher in arm than in leg work: the reasons for this difference are discussed.