Effect of ramp rate and reliability of peak physiological responses during arm crank ergometry

Abstract

Introduction: Asynchronous arm crank ergometry (ACE) is a viable mode of exercise testing for specific groups (e.g. wheelchair-bound individuals, kayakers) and is employed within clinical settings for the purpose of rehabilitation. This study aimed to; (1) investigate peak physiological responses to three ACE tests varied with respect to ramp rate, (2) from these to identify an optimal test based upon the attainment of vo2 peak. and (3) to assess the extent of test-retest reliability for each selected parameter. This was achieved by way of requiring individuals to repeat their optimal test. Methods: Eighteen healthy men performed three exercise tests, differentiated in ramp rate, in a random order. These consisted of a standard 4 min warm-up after which time the workload increased by 6 (T1), 10 (T2) or 12 W.min-1 (T3). An imposed crank rate of 80 rev.min-1 was maintained throughout all tests. The optimal test (Topt) for each subject was defined as that which elicited the highest value of oxygen consumption ( V02 peak). In order to assess test-retest reliability Topt was repeated. Systematic bias for all parameters between T1, T2 and T3 was assessed using separate one-way ANOVA tests with repeated measures. Reliability of the parameters was assessed using a number of conventional statistical procedures. Results: Peak power output (PPO) was significantly higher (P<0.05) with the 12 W·min-1 ramp test. Peak lactate (Hlapeak), peak respiratory exchange ratio (RERpeak) and PPO were significantly lower (P<0.05) in T1. There was no systematic change between test-retest (P>0.05) and all measures were within 10% variation as determined by 95% confidence intervals (95%CI). Conclusions: T2 and T3 are both equally appropriate for eliciting peak physiological responses in ACE while T3 is most appropriate for peak functional capacity. Traditional reliability measures suggested an appropriate level of test-retest reproducibility.