The effect of continuous and intermittent exercise on blood and sweat lactate concentrations

The purpose of this study was to determine if a relationship exists between sweat lactate concentrations and blood lactate concentrations during exercise. Eight males served as subjects for the experimental testing protocol.

All subjects performed continuous exercise on a bicycle ergometer at 60% VO₂ max and intermittent exercise at 100% VO₂ max to create variable blood lactate concentrations. The exercise bouts were 60 minutes in duration and were separated by approximately one week. Measurements of blood lactate were taken at 20, 40, and 60 minutes of exercise and sweat lactate was measured via whole body washdown.

There was no significant difference in sweat lactate concentrations (P = 0.49) between continuous (92.4 +- 34.9 mg/dl) and intermittent exercise (80.9 +- 23.2). Blood lactate concentrations for intermittent exercise (50.0 +- 4.8) was significantly higher (P = 0.0082) than those for the continuous exercise (25.6 +- 3.6). Regression line analysis showed no significant relationship between sweat and blood lactate conentrations (r = .30).

These results indicate that a significant correlation does not exist between sweat lactate concentrations and blood lactate concentrations.

Key Words: Lactate, Continuous, Intermittent, Sweat, Blood, Exertion