Physiological Responses to Standardised Arm Work

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.