PURPOSE: Maximum oxygen uptake (VO₂max) and ventilatory thresholds (VT) obtained from an exercise test are indicators of functional capacity. Additionally, they can be employed to prescribe exercise and to evaluate the evolution of an exercise program. For upper-body exercise, the arm-crank exercise test is considered the gold standard to estimate VO₂max. Recently, boxing training has been employed as an upper-body physical activity modality in cardiovascular disease populations to improve health outcomes, such as cardiorespiratory fitness. However, according to the specificity principle of exercise training, changes on physical fitness are better reflected if the same modality of exercise is being used during its assessment. Therefore, the purpose of this study was to compare VO₂max and VT estimations between boxing and arm-crank exercise test.
METHODS: Twelve subjects (8 males, 4 females) performed a boxing exercise test by repeatedly executing the boxing combination of right hook and left hook. A metronome set a tempo for participants to follow throughout the exercise protocol; for males, the metronome started at 140 Beats Per Minute (BPM) and increased by 30 BPM after every stage until exhaustion; for females, the tempo was set to 125 BPM and increased 30 BPM after every 2-minute stage until exhaustion. When performing the arm-crank exercise test, participants pedaled at a range of 50 to 60 revolutions per minute. Male subjects start pedaling at 50 Watts (W) resistance and would increase 15 W at the end of each 2-min stage until exhaustion. Female subjects pedaled at 40 W resistance and would increase by 10 W at the end of each stage until exhaustion. Throughout both exercise tests, VO₂ was constantly recorded. Statistical analysis included Bland-Altman analysis for agreement and Pearson correlation for strength of association.
RESULTS: Although VO₂max and ventilatory threshold showed statistical agreement between both exercise modalities (VO₂max 95% CI [−7.6 to 6.7], VT 95% CI [−29.1 to 21,4]), clinical agreement was not obtained. Additionally, there was a strong association for VO₂max (r: 0.7, p <0.05) and a weak correlation for VT (r: 0.2, p<0.05)
CONCLUSIONS: Exercise tests should be specific for the exercise modality that is being used for training.