Heart Rate, Arterial Lactate Concentration and Oxygen Uptake During Exercise in Old Men Compared with Young Men

Abstract In 121 healthy men aged 30–83 years heart rate, oxygen uptake, arterial lactate and pyruvate concentrations were studied during stepwise increased work loads on a bicycle ergometer. The relationship between heart rate and work load was not affected by age but the final heart rate and work load decreased with age. In the younger ages the most usual reason for breaking off the test was fatigue in the legs, in the higher ages dyspnoea. The regression line for log lactate on heart rate during exercise was on a higher level in old men than in young. Blood lactate during exercise was correlated both to the degree of circulatory steady state, the heart rate, and the final work load irrespective of age. The relationship between lactate and excess lactate during exercise was similar in old and young men, excess lactate being equivalent to lactate reduced by 2 mM/1. In 20 men aged 60–83 years there was at 600 kpm/min a negative correlation between mechanical efficiency and heart rate and a positive between oxygen uptake and weight or heart rate. No correlation was found between oxygen uptake or mechanical efficiency and age, degree of circulatory steady state or blood lactate concentration.