V L Goosey1, I G Campbell, N E Fowler. 1. Department of Exercise and Sport Science, Manchester Metropolitan University, Alsager, United Kingdom. v.l.goosey@mmu.ac.uk
Abstract
PURPOSE: The aim of the study was to examine the effect of varying push frequency on pushing economy (oxygen uptake at a given speed). METHODS:Eight male wheelchair racers completed a series of exercise bouts on a wheelchair ergometer (Bromking Turbo Trainer, Bromakin, UK) at 6.58 m x s(-1). Initially, subjects self-selected their freely chosen push frequency (FCF); this was followed by 4 random trials pushing at 60, 80, 120, and 140% of this FCF. Steady state VO2 was determined using Douglas bags, and heart rate was recorded by telemetry. After each condition, a small capillary blood sample was obtained and analyzed for blood lactate concentration (BLa) and a rating of perceived exertion (RPE) was recorded. RESULTS: At 6.58 m x s(-1) oxygen uptake, RPE, and gross mechanical efficiency were nonlinearly related to push frequency. Analysis of variance showed a significant effect (P < 0.05) of cycle frequency on VO2. VO2 was 11% higher at the 140% FCF compared with the 100% FCF condition. Changes in push frequency had little effect on HR although BLa increased linearly and was higher at the 140% FCF condition compared with 60% FCF (P < 0.05). A two-dimensional sagittal plane video analysis showed large interindividual differences in propulsion style. Both cycle time and the propulsion phase (%) decreased as the push frequency increased. The start angle and end angle of hand contact were similar for conditions, whereas the range of trunk motion decreased with push frequency (P < 0.05). CONCLUSION: The results of this study showed that the push frequency had an effect on pushing economy, and that the athletes' FCF was the most economical.
RCT Entities:
PURPOSE: The aim of the study was to examine the effect of varying push frequency on pushing economy (oxygen uptake at a given speed). METHODS: Eight male wheelchair racers completed a series of exercise bouts on a wheelchair ergometer (Bromking Turbo Trainer, Bromakin, UK) at 6.58 m x s(-1). Initially, subjects self-selected their freely chosen push frequency (FCF); this was followed by 4 random trials pushing at 60, 80, 120, and 140% of this FCF. Steady state VO2 was determined using Douglas bags, and heart rate was recorded by telemetry. After each condition, a small capillary blood sample was obtained and analyzed for blood lactate concentration (BLa) and a rating of perceived exertion (RPE) was recorded. RESULTS: At 6.58 m x s(-1) oxygen uptake, RPE, and gross mechanical efficiency were nonlinearly related to push frequency. Analysis of variance showed a significant effect (P < 0.05) of cycle frequency on VO2. VO2 was 11% higher at the 140% FCF compared with the 100% FCF condition. Changes in push frequency had little effect on HR although BLa increased linearly and was higher at the 140% FCF condition compared with 60% FCF (P < 0.05). A two-dimensional sagittal plane video analysis showed large interindividual differences in propulsion style. Both cycle time and the propulsion phase (%) decreased as the push frequency increased. The start angle and end angle of hand contact were similar for conditions, whereas the range of trunk motion decreased with push frequency (P < 0.05). CONCLUSION: The results of this study showed that the push frequency had an effect on pushing economy, and that the athletes' FCF was the most economical.
Authors: Lisa A Zukowski; Jaimie A Roper; Orit Shechtman; Dana M Otzel; Jason Bouwkamp; Mark D Tillman Journal: Arch Phys Med Rehabil Date: 2013-09-06 Impact factor: 3.966
Authors: Thomas Edwards; J P Barfield; Grace M Niemiro; Joseph W Beals; Elizabeth M Broad; Robert W Motl; Michael De Lisio; Nicholas A Burd; Lara A Pilutti Journal: Spinal Cord Ser Cases Date: 2018-08-14