Maximal heart rates and plasma lactate concentrations observed in middle-aged men and women during a maximal cycle ergometer test.

The purpose of this study was to investigate criteria for maximal effort in middle-aged men and women undertaking a maximal exercise test until they were exhausted if no measurements of oxygen uptake are made. A large group of 2164 men and 975 women, all active in sports and aged between 40 and 65 years, volunteered for a medical examination including a progressive exercise test to exhaustion on a cycle ergometer. In the 3rd min of recovery a venous blood sample was taken to determine the plasma lactate concentration ([la-]p,3 min). Lactate concentration and maximal heart rate (fc,max) were lower in the women than in the men (P < 0.001). Multiple regression analyses were performed to assess the contribution of sex to [la-]p,3 min, independent of age and fc,max. It was found that [la-]p,3 min was about 2.5 mmol.l-1 lower in women than in men of the same age and fc,max. In our population 88% of the men and 85% of the women met a combination of the following fc,max and [la-]p,3 min criteria: fc,max equal to or greater than 220 minus age beats.min-1 and/or [la-]p,3 min equal to or greater than 8 mmol.l-1 in the men and fc,max equal to or greater than 220 minus age beats.min-1 and/or [la-]p,3 min equal to or greater than 5.5 mmol.l-1 in the women.