The influence of dynamic exercise on fatiguing isometric exercise and the assessment of changing levels of "isometric component."
Lind-AR; Rochelle-RH; Petrofsky-JS; Rinehart-JS; Burse-RL
NIOSH 1975 Jun; :1-55
Three men trained in exercise on a bicycle ergometer and a leg dynamometer were tested to determine the magnitude of the static component in a work task and to assess quantitatively the effectiveness of dynamic exercise in the elimination or reduction of fatigue due to static effort. During cycling at 50 revolutions per minute, the longest duration of fatiguing isometric exercise at 40 percent maximal voluntary contraction occurred just after cycling at 20 percent maximum oxygen uptake; these contractions were slightly longer than those in the resting subject. The duration of test contraction increased with the increase in the severity of cycling, but fatigue induced by heavier cycling levels was reduced or dissipated by a brief bout of light cycling. For any level of mechanical work done, cycling at 30 revolutions per minute had a deleterious effect on the duration of subsequent isometric exercise, a finding which demonstrates the existence of a higher level of static component at slow speeds of work which are accompanied by a higher muscular tension.
NIOSH-Contract; Contract-099-71-0021; Physical-exercise; Cardiovascular-function; Respiratory-functions; Metabolic-rate; Test-methods; Energy-expenditure; Muscle-function; Muscle-contraction; Physiology; Endurance
NTIS Accession No.
(NIOSH) 75-177; Contract-099-71-0021
National Institute for Occupational Safety and Health