Burt H, Koehler B, Sudimack G, Bouillon C, Van Zant S; Physical Therapy Research Lab, University of Findlay, Findlay, OH. vanzant@findlay.edu.

PURPOSE: The purpose of the study was to determine the inter- and intra-reliability of submaximal exercise on the strength cycle ergometer. BACKGROUND: The strength cycle is a new type of ergometer that permits both an engaged (E) mode typical of standard cycling, as well as a disengaged (DE) mode in which each pedal works independently (essentially concurrent single leg cycling). Resistance is produced by a spring-loaded friction pad applied to the flywheel at various "undefined" settings lacking any method of calibration. No data is available regarding the inter- or intra-reliability of exercise using this ergometer. SUBJECTS: Eight healthy recreationally active subjects (5 males, 3 females; 24 ± 5.6 yr; 12.8 ± 6.4% fat; 4.0 ± 1.3 l^.min^-1 VO_2peak) gave their informed consent to participate in this study. METHODS: Subjects were randomized into 6 exercise trials (3 for bike 1 and 3 for bike 2) in a double-blinded fashion. Subjects pedaled at 60 rpm through progressive 3 min stages (resistance settings) to an end point of 85% HRmax. Each stage consisted of 90 sec in both the E and DE cycling modes. VO₂, HR, and RPE were measured every 90 sec of each continuous exercise trial. ANALYSIS: Pearson correlations were performed using SPSS 9.0 for both inter- and intra-reliability. RESULTS: No significant differences were found between the cycles for VO₂, HR, or RPE, (p<0.05) for stages 1-5 in both E and DE modes. Significant intra-reliability relationships were found in both E & DE modes for VO₂ and RPE at stages 1, 2 and 3 throughout the 3 trials (r²=0.82-0.96, p<0.05). In nearly every stage, there were significant correlations for bike 1 and bike 2 in E &DE modes for HR throughout the 3 trials (r²=0.84-0.90, p<0.05). CONCLUSIONS: This study showed that there appears to be no differences between the 2 strength cycles during submaximal exercise. Moreover, the resistance settings for both Reebok strength cycles elicited similar VO₂ and RPE responses at the initial stages, and at all stages for HR during multiple trials. FUNDING SOURCE: None.

Reprint Information
Requests for reprints should be directed to the corresponding author of the article. Students and other academic customers may receive permission to reprint copyrighted material from Physical Therapy by contacting the Copyright Clearance Center Inc, 222 Rosewood Dr, Danvers, MA 01923. Similar inquiries by all others should be made to the APTA Editorial Office, Attn: Physical Therapy.