z_bumbi
2012-03-01, 19:22
Med Sci Sports Exerc. 2012 Feb 9. [Epub ahead of print]
VO2max May Not Be Reached During Exercise to Exhaustion above Critical Power.
Sawyer BJ, Morton RH, Womack CJ, Gaesser GA.
Source
1Arizona State University, School of Nutrition and Health Promotion, Phoenix, AZ 2Massey University, School of Sport and Exercise, Palmerston North, New Zealand 3James Madison University, Department of Kinesiology, Harrisonburg, VA.
Abstract
PURPOSE:
This study was designed to determine whether VO2 reaches a maximum, equivalent to that attained in an incremental exercise test to exhaustion, during "submaximal" fatigue-inducing constant-power exercise bouts above Critical Power (CP).
METHODS:
Nine males (age: 24.6 ± 3.6 yr.; ht: 182.8 ± 6.9 cm; wt: 77.8 ± 12.1 kg) and 4 females (age: 29.0 ± 7.3 yr.; ht: 170.8 ± 3.2 cm; wt: 61.8 ± 8.2 kg) underwent an incremental VO2max test (IET) on a cycle ergometer, followed by 4 or 5 randomly assigned, constant-power exercise bouts to exhaustion, on separate days. Critical power for each subject was estimated using linear and nonlinear regression.
RESULTS:
IET VO2max averaged 3.55 ± 0.92 l/min (Respiratory exchange ratio = 1.21 ± 0.05; heart rate = 186 ± 10 bpm; 96.1 ± 6.3% age-predicted max). Mean peak VO2 (range 3.32 ± 0.88 to 3.54 ± 0.91 l/min) during the 3 highest constant-power bouts (two of which were 53 to 82 W less than peak power output attained during IET) was not significantly different than IET VO2max. Eleven of 13 subjects exceeded their IET VO2max during at least one of the constant-power exercise bouts. However, peak VO2 (3.11 ± 0.79 l/min) during the lowest constant-power exercise bout, which ranged from 10 W to 36 W above CP estimated with a 2-parameter nonlinear model, was significantly lower than IET VO2max (88.2 ± 9.4% of IET VO2max).
CONCLUSIONS:
At power outputs above CP, VO2 does not necessarily increase to maximum during constant-power exercise to exhaustion. Additionally, the highest VO2 values measured during a traditional VO2 "max" test (i.e., IET) may not reflect the highest attainable VO2 despite VO2max criteria being met.
VO2max May Not Be Reached During Exercise to Exhaustion above Critical Power.
Sawyer BJ, Morton RH, Womack CJ, Gaesser GA.
Source
1Arizona State University, School of Nutrition and Health Promotion, Phoenix, AZ 2Massey University, School of Sport and Exercise, Palmerston North, New Zealand 3James Madison University, Department of Kinesiology, Harrisonburg, VA.
Abstract
PURPOSE:
This study was designed to determine whether VO2 reaches a maximum, equivalent to that attained in an incremental exercise test to exhaustion, during "submaximal" fatigue-inducing constant-power exercise bouts above Critical Power (CP).
METHODS:
Nine males (age: 24.6 ± 3.6 yr.; ht: 182.8 ± 6.9 cm; wt: 77.8 ± 12.1 kg) and 4 females (age: 29.0 ± 7.3 yr.; ht: 170.8 ± 3.2 cm; wt: 61.8 ± 8.2 kg) underwent an incremental VO2max test (IET) on a cycle ergometer, followed by 4 or 5 randomly assigned, constant-power exercise bouts to exhaustion, on separate days. Critical power for each subject was estimated using linear and nonlinear regression.
RESULTS:
IET VO2max averaged 3.55 ± 0.92 l/min (Respiratory exchange ratio = 1.21 ± 0.05; heart rate = 186 ± 10 bpm; 96.1 ± 6.3% age-predicted max). Mean peak VO2 (range 3.32 ± 0.88 to 3.54 ± 0.91 l/min) during the 3 highest constant-power bouts (two of which were 53 to 82 W less than peak power output attained during IET) was not significantly different than IET VO2max. Eleven of 13 subjects exceeded their IET VO2max during at least one of the constant-power exercise bouts. However, peak VO2 (3.11 ± 0.79 l/min) during the lowest constant-power exercise bout, which ranged from 10 W to 36 W above CP estimated with a 2-parameter nonlinear model, was significantly lower than IET VO2max (88.2 ± 9.4% of IET VO2max).
CONCLUSIONS:
At power outputs above CP, VO2 does not necessarily increase to maximum during constant-power exercise to exhaustion. Additionally, the highest VO2 values measured during a traditional VO2 "max" test (i.e., IET) may not reflect the highest attainable VO2 despite VO2max criteria being met.