Assessment Of Exercise Capacity Using Arm Crank Ergometer Among Healthy Adults

Assessments of exercise capacity in recovery periods after injury, as well as rehabilitation programs aiming to maintain exercise capacity, are critical for athletes to return early to training and competition activities. When an athlete got injured lower limbs, exercise testing with lower limb exercise might be substituted by that with upper limb exercise in the assessment of exercise capacity. However, exercise test protocol with upper limb exercise has not been established, and only few exercises testing with upper limb exercise has been reported. PURPOSE: The present study aimed to evaluate the validity of exercise testing with upper limb exercise in the assessment of exercise capacity. METHODS: Seven healthy participants (26.7 ± 10.6 years, 5 males) with habitual exercise underwent an incremental exercise testing using arm crank ergometer (ACE; + 12.5 watt / 3 min) or cycle ergometer (CE; + 25 watt / 3 min) on two separate days. Heart rate (HR), oxygen uptake (VO2) and rating of perceived exertion (RPE) were monitored throughout the tests. Linear Mixed Effect (LME) regression model in which VO2 was set as a dependent variable and HR, exercise modalities (EM) and an interaction between HR and EM as independent variables was used to evaluate whether the correlation between HR and VO2 during the exercise testing is modified by the EM, that is, ACE and CE. RESULTS: LME regression model showed that the correlation between HR and VO2 was significantly different between the exercise testing with ACE and that with CE (p < 0.001). HR-VO2 regression equations in each EM of each participant were calculated to estimate maximal oxygen uptake (VO2max) from age-predicted maximal HR (HR = 220 - age). Estimated VO2max in ACE were significantly lower than those in CE in all participants (36.3 ± 12.7 vs. 52.8 ± 16.7 mL/kg/min, p = 0.002). These results suggested the possibility that exercise capacity was underestimated by using results obtained from exercise testing with ACE. CONCLUSION: The possibility of underestimating exercise capacity needs to be kept in mind when estimating exercise capacity from exercise testing with ACE. Further research is needed to elucidate factors affecting the correlation between HR and VO2 in assessing exercise capacity with ACE.