title: Assessment of the anaerobic threshold during exercise in normal man by means of the occlusion pressure as compared to conventional noninvasive techniques.
abstract: 7 healthy men performed on a bicycle a stepwise increasing maximal exercise. During the work test the classical parameters usually used in the detection of the anaerobic threshold (AT) i.e. minute ventilation (VE), CO2 output (VCO2), O2 intake (VO2), gas exchange ratio (R) were recorded by a computerized system every minute. We also recorded the occlusion pressure (Po.1) in order to introduce it as a new parameter to detect the anaerobic threshold. Po.1 evolution showed a clear 'breaking point' at approximatively the same levels as for some of the other parameters (VE, VCO2). This 'breaking point' which is interpreted as the AT was also situated at the same level where VE/VO2 ratio increases without a change in VE/VCO2 ratio. Moreover the 'breaking point' separated the curves in linear and nonlinear increases as for VE and VCO2. By comparing the slope of the evolution of VCO2, VE, and Po.1 before and after the AT, it appeared that the easier visual detection of the AT was made by the Po.1 profile. We conclude that Po.1 is a valid index to detect the AT, and that this technique is a useful parameter in order to improve the visual detection of the AT.
mesh_terms: D000328:Adult; D000693:Anaerobiosis; D002245:Carbon Dioxide / Q000097:blood; D004734:Energy Metabolism; D005080:Exercise Test; D006801:Humans; D008297:Male; D010100:Oxygen / Q000097:blood; D011659:Pulmonary Gas Exchange; D014692:Ventilation-Perfusion Ratio
chemical_list: D002245:Carbon Dioxide; D010100:Oxygen