Second ventilatory threshold from heart-rate variability: valid when the upper body is involved?
To determine the most accurate method based on spectral analysis of heart-rate variability (SA-HRV) during an incremental and continuous maximal test involving the upper body, the authors tested 4 different methods to obtain the heart rate (HR) at the second ventilatory threshold (VT(2)). Sixteen ski mountaineers (mean ± SD; age 25 ± 3 y, height 177 ± 8 cm, mass 69 ± 10 kg) performed a roller-ski test on a treadmill. Respiratory variables and HR were continuously recorded, and the 4 SA-HRV methods were compared with the gas-exchange method through Bland and Altman analyses. The best method was the one based on a time-varying spectral analysis with high frequency ranging from 0.15 Hz to a cutoff point relative to the individual's respiratory sinus arrhythmia. The HR values were significantly correlated (r(2) = .903), with a mean HR difference with the respiratory method of 0.1 ± 3.0 beats/min and low limits of agreements (around -6 /+6 beats/min). The 3 other methods led to larger errors and lower agreements (up to 5 beats/min and around -23/+20 beats/min). It is possible to accurately determine VT(2) with an HR monitor during an incremental test involving the upper body if the appropriate HRV method is used.
Culture Sport Health Society and Exercise Performance and Health, Innovation Platform, University of Franche-Comté, Besançon, France.
Laurent
L
Mourot
Nicolas
N
Fabre
Aldo
A
Savoldelli
Federico
F
Schena
D000328:Adult; D015308:Anaerobic Threshold; D001944:Breath Tests; D005080:Exercise Test; D006339:Heart Rate; D006801:Humans; D008124:Locomotion; D008168:Lung / Q000502:physiology*; D008297:Male; D009051:Mountaineering; D009119:Muscle Contraction; D018763:Muscle Fatigue; D018482:Muscle, Skeletal / Q000502:physiology*; D010101:Oxygen Consumption; D011237:Predictive Value of Tests; D011659:Pulmonary Gas Exchange; D012123:Pulmonary Ventilation; D015203:Reproducibility of Results; D012865:Skiing; D013997:Time Factors; D060726:Torso; D034941:Upper Extremity; D055815:Young Adult