Ventilatory Thresholds in Arm and Leg Exercises with Spontaneously Chosen Crank and Pedal Rates

The present study assessed whether the first and the second ventilatory thresholds (VT₁ and VT₂) were dependent on the muscle groups solicited when spontaneously chosen crank and pedal rates are used. 20 physical education male students (22 ± 2.2 yr.) performed two maximal incremental tests randomly assigned using an increment of 15 and 30 W every minute for arm and leg exercises, respectively. These tests were used to measure the maximal oxygen uptake (VO₂ max) and to identify VT₁ and VT₂. The absolute oxygen uptake (VO₂) values measured at VT₁, VT₂, and at maximal workload were significantly (p<.05) lower during arm and leg exercises. However, VT₁ and VT₂ expressed in percent of VO₂ max were not significantly different between arm and leg exercises (54.1 ± 8.2 vs 57.2 ± 11.4%; and 82.5 ± 6.4 vs 84.6 ± 5.1% at VT₁ and VT₂, respectively). In addition, at the two thresholds, none of the variables measured during arm and leg exercises were significantly correlated with the exception of spontaneously chosen crank and pedal rates (p<.01; r=.75 and r=.69 for VT₁ and VT₂, respectively). Probably due to the different training status and skill level, no extrapolation can be made to specify the arm thresholds from the leg. These results underline the need to specify the ventilatory thresholds from specific arm ergometer measures obtained from tests performed with spontaneously chosen crank and pedal rates and, thus, close to sport and recreational activities, when they are used for training and rehabilitation programs.