|dc.description.abstract||Objectives: This study determined peak physiological responses, and explored their relationship during graded asynchronous arm trunk powered (ATP) arm crank ergometry (ACE) and synchronous arm powered (AP) handcycling (HC).
Methods: Eighteen men (age 21 (2); yr, stature 1.80 (0.06) m; body mass 80.5 (8.4) kg) volunteered and provided written informed consent once the study had gained institutional ethical approval. Following familiarisation all participants completed the tests in a counterbalanced order; both tests started at 50 W with subsequent increments of 20 W every 2-min. Respiratory exchange data and heart rate (HR) were recorded continuously, the peak power output (Wpeak) was calculated from the average power maintained during the final minute of test. Blood lactate concentration (B[La]; mmol.l-1) was measured at the end of exercise, as well as after 5-min of a period of active recovery. The first ventilatory threshold (VT1) was calculated by plotting VO2 (ml.min-1) against VCO2 (ml.min-1), a procedure referred to as the V-slope method. Average values of VCO2 and VE calculated during consecutive 30-s intervals throughout each test were used to determine the work rate associated with the second ventilatory threshold (VT2) know as the respiratory compensation point. The work rate associated with VT2 was expressed in both absolute (W) and relative (%Wpeak) terms. The respective magnitudes of all parameters were compared using separate paired T-tests, and the relationships between them were explored by calculating correlation coefficients.
Results: Wpeak was higher (p<0.05) during ACE [152 (23) W] compared to HC [122 (22) W]. No difference existed between end B[La] during ACE [10.9 (2.4) mmol.l-1] and HC [11.3 (1.6) mmol.l-1], but HRpeak [184 (10) vs. 175 (10) b.min-1], and all other peak respiratory responses were higher (P<0.05) during ACE compared to HC. Difference (P<0.05) were observed for VO2peak [3.05 (0.55) vs. 2.60 (0.41) l.min-1], VCO2peak [3.53 (0.66) vs. 3.21 (0.47) l.min-1] and VEpeak [137.2 (32.4) vs. 125.9 (27.5) l.min-1], respectively. The absolute work rates associated with both VT1 and VT2 were significantly higher (P<0.05) during ACE than HC, [VT1 ACE 48 (19.7) versus HC 99 (16) W] and VT2 ACE [116 (15) HC 99 (16) W]. Relative work rates were however similar at both ventilatory thresholds VT1 [48 (8) vs. 49 (9) %Wpeak], and VT2 [77 (10) vs. 79 (13) %Wpeak] for ACE and HC respectively. Significant (P<0.05) correlation coefficients were observed for all physiological data Wpeak (r = 0.85), absolute VO2peak (r = 0.86), relative VO2peak (r = 0.88), VEpeak (r = 0.77), and HRpeak (r = 0.77), the relative work rate associated with VT2 (r = 0.78) and end B[La] (r = 0.81). There was no difference (P<0.05) in delta efficiency (which considers changes in power output, work done and associated aerobic energy expenditure) between ACE 15 (3)% and HC 16 (2)%. Conclusions: Asychronous ATP ACE generally elicited higher peak physiological responses in comparison to synchronous AP HC. It is likely this is due to the more functional upright body position where the feet are in contact with the floor in a closed kinetic chain and thus able to recruit a greater muscle mass and thus produce more power than the open kinetic chain HC. The results of this study confirm that either test could be employed to provide an estimation of a participant’s peak physiological responses and functional capacity for individuals unable to conduct a standard whole body exercise test and for athletes participating in upper body sports. A strong relationship existed between many of the objective parameters, and further research is warranted in this emerging area using able bodied and physically disabled participants who can be considered as being upper body trained.||en_US