Validity of the heart rate deflection point as a predictor of lactate threshold concepts during cycling.
This paper examines the validity of the heart rate deflection point (HRDP) obtained with the "updated" Conconi test. Eleven male road cyclists performed 2 progressive incremental cycling tests and a 30-minute prolonged exercise test (PET). From the data obtained, comparisons were made and correlation coefficients were calculated between HRDP, the lactate threshold (LT), and the 3 mmol.L(-1) threshold (AT3). The PET at HRDP demonstrated whether or not a steady state in blood lactate concentration (BLaSS) could be maintained. Significantly lower values for power output (p < 0.01) and heart rate (HR) (p < 0.01) were found at LT compared with HRDP. No differences were found between HRDP and AT3. Only a moderate correlation for power output between HRDP and AT3 (rs = 0.69; p < 0.05) could be observed. During the PET, only 6 out of 11 cyclists reached the target time of 30 minutes, and only 4 cyclists maintained a BLaSS. We conclude that the updated Conconi test is not a valid method for assessing LT or AT3. Therefore, this method seems not suitable to evaluate endurance performance and prescribe exercise intensities in road cycling.
Bourgois
Jan
J
Centre of Sports Medicine, Ghent University Hospital, Belgium. jan.bourgois@UGent.be
Coorevits
Pascal
P
Danneels
Lieven
L
Witvrouw
Erik
E
Cambier
Dirk
D
Vrijens
Jacques
J
D000328:Adult; D015308:Anaerobic Threshold / Q000502:physiology*; D001642:Bicycling / Q000502:physiology*; D015444:Exercise / Q000502:physiology; D005080:Exercise Test / Q000379:methods*; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D019344:Lactic Acid / Q000097:blood*; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology; D015203:Reproducibility of Results
D019344:Lactic Acid