Haber P, Niederberger M, Kummer F, Ferlitsch A
Schweiz Med Wochenschr. 1978 Apr 29;108(17):652-4.
Maximal work endurance of heart and circulation measured by submaximal work load on an ergometer can be estimated with reasonable accuracy by means of the physical working capacity 170 (PWC 170) only in healthy individuals aged 30 years or below. Limitation of exercise by pulmonary factors does not appear to bias the results essentially. In healthy people aged 40 or over, the risk of miscalculating maximal working ability based on PWC 170 increases considerably despite maintenance of high statistical correlation to maximal work load. In patients with coronary heart disease, there is no statistical correlation between PWC 170 and maximal work load; therefore, symptom-limited ergometry is required in these patients. For the assessment of quality in follow-up tests, the watt-pulse at submaximal work load appears to be the most adequate parameter. It is recommended that submaximal tests be also carried out in a rectangular-triangular manner, for the purpose of comparison with symptom-limited tests and for evaluation of changes in the dynamics of pulse and blood pressure regulation.
