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 (VO2) 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) degrees C in AV and was higher in NAV [36.7 (0.2) degrees 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 VO2 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.
Van Schuylenbergh
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R
Exercise Physiology and Biomechanics Laboratory, Department of Kinesiology, Faculty of Physical Education and Physiotherapy, K.U. Leuven, Tervuursevest 101, 3001, Leuven, Belgium.
Vanden Eynde
B
B
Hespel
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P
D000222:Adaptation, Physiological / Q000502:physiology; D000293:Adolescent; D000328:Adult; D000392:Air Movements; D001833:Body Temperature Regulation / Q000502:physiology; D004735:Energy Transfer / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test / Q000379:methods*; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D010101:Oxygen Consumption / Q000502:physiology; D005082:Physical Exertion / Q000502:physiology*; D013647:Task Performance and Analysis; D014691:Ventilation / Q000379:methods*
D019344:Lactic Acid