Laddermill and Ergometry: A Comparative Summary

Abstract

The merits of the laddermill as an ergometer for measuring man's major physiological responses to work are presented, together with a literature-based summary of other commonly used ergometers. The paper shows that the relationships between oxygen uptake, work rate, pulmonary ventilation, and heart rate can be described in simple linear equations. The linear relationship between the oxygen uptake (energy expenditure) and the work rate for ladder-climbing, cycling, cranking, and running are presented and the more complicated relationship of oxygen uptake to walking speed is discussed. In addition, the linear relationships of oxygen uptake to ventilation and to heart rate are given for arms and legs at submaximal and maximal work levels. The work efficiency for each ergometer is analyzed on the basis of the coefficient of regression of the oxygen uptake on the work load. The limitations of the ergometers in achieving maximal aerobic capacity are considered in the light of reported electromyographic evidence. The relatively intensive or extended periods of muscle contractions apparent during cycling and stool-stepping support the view that ischemic muscle contraction might be the cause for the lower maximal value obtained on these ergometers as compared to that obtained on a treadmill.