Assessment Of Exercise Capacity With Submaximal Exerxise Using Arm Crank Ergometer: Comparison With Cycle Ergometer

Exercise capacity assessed by exercise testing with arm crank ergometer (ACE) may be underestimated because the subjects cannot reach the exercise intensity for maximal oxygen uptake (VO2max). VO2max can be estimated using the correlation formula between heart rate (HR) and oxygen uptake (VO2) during submaximal exercise and age-predicted maximal HR. If the VO2max can be estimated by submaximal exercise testing with ACE, ACE can be a useful option, instead of cycle ergometer (CE), to assess exercise capacity. However, it has not been elucidated whether the correlation between HR and VO2 is same during submaximal exercise between with ACE and CE. Furthermore, although there is the possibility that training status of upper limb might influence the correlations between HR and VO2 during exercise with ACE, it is unclear whether or not that is true. PURPOSE: The present study aimed to clarify whether submaximal exercise testing with ACE can substitute for that with CE to assess exercise capacity. METHODS: Nine male collegiate rowers and eight male collegiate cyclists (19.4 ± 0.9 vs. 20.3 ± 1.0 years) underwent an incremental exercise testing with ACE (+ 12.5 watt / 3 min) and CE (+ 25 watt / 3 min) on two separate days. HR and VO2 were monitored during the tests. Segmental muscle mass was measured to assess training status of upper limb. For each subject, regression equations representing the correlation between HR and VO2 in each exercise modality were created, and VO2max was estimated using this equations and age-predicted maximal HR. RESULTS: Muscle mass of brachium, upper limb, and trunk were greater in the rowers than in the cyclists (ps < 0.05). The correlations between HR and VO2 was significantly different depending on exercise modalities in both groups (ps < 0.001). Estimated VO2max was significantly lower in the exercise testing with ACE than in that with CE in the rowers and cyclists (41.7 ± 7.3 vs. 52.6 ± 8.6 mL/kg/min, p = 0.010 and 35.5 ± 14.2 vs. 50.4 ± 13.4 mL/kg/min, p = 0.011, respectively). CONCLUSION: Results suggested that exercise capacity assessed by submaximal exercise testing with ACE is underestimated, regardless of training status of upper limb. Exercise testing with ACE cannot substitute for that with CE, at least for the estimation of VO2max. Practitioners involved in exercise testing need to keep this in mind. Collaborative Research Grant for Cooperative Research from Osaka Metropolitan University: FY2022