Effects of air ventilation during stationary exercise testing

The impact of air ventilation on performance and physiological responses during stationary exercise in the laboratory was studied. Fourteen well-trained cyclists performed three exercise tests on a cycle ergometer, each separated by a 1-week interval. The first test was a graded test to determine the power output corresponding with the 4-mmol l−1 lactate level. Tests 2 and 3 were 30-min constant-load tests at a power output corresponding with this 4-mmol l−1 lactate threshold. One constant-load test was performed in the absence (NAV), whilst the other was performed in the presence (AV) of air ventilation (3 m s−1). During the constant-load tests, heart rate, tympanic temperature, blood lactate concentration and oxygen uptake (V̇O2) were measured at 10-min intervals and at the end of the test. Differences between the two test conditions were evaluated using paired t-tests. During NAV, 12 subjects interrupted the test due to premature exhaustion (exercise duration <30 min), versus only seven in AV (P<0.05). At the end of the test tympanic temperature was 35.9 (0.2)°C in AV and was higher in NAV [36.7 (0.2)°C, P<0.05]. Exercise heart rate increased at a faster rate during NAV [+2.2 (0.3) beats min−1] than during AV [+1.5 (0.2) beats min−1, P<0.05]. Blood lactate concentration and V̇O2 were similar between conditions. Air ventilation is essential to prevent an upward shift in the lactate:heart rate as well as the power output:heart rate relationship during laboratory exercise testing and indoor exercise training.