Variability of peak physiological responses during upper body ergometry
Conference Contribution ResearchOnline@JCUAbstract
Introduction: For reliability/variability studies of VO2peak assessment, values within 4-6% of each other have been reported for treadmill protocols however, similar studies examining upper body ergometry have been lacking. Therefore, the aim of the current study was to determine the variability of peak physiological responses associated with repeated bouts of upper body exercise, namely arm crank and outrigger canoeing ergometry. Methods: Participants (n = 43, 24.9 ± 7.3 yr, 1.73 ± 0.26 m, 76.3 ± 5.0 kg, 23.7 ± 79% body fat) completed two upper body ergometer trials (arm crank graded exercise test [GXT] with 15 females; GXT with 18 males; or 1000 m outrigger ergometer time trials [TT] with 10 females) separated by 7 days. Testing procedures were approved by the Research Ethics Committee and written informed consent was obtained from all participants prior to testing. The GXT protocols consisted of 16 W increments per 1-2 mins using an arm crank ergometer (Monark 881E Rehab Trainer, Monark, Varberg). The TT consisted of participants completing 1000 m on a rowing ergometer (Concept II, Morrisville, USA) modified with an outrigger attachment (Vermont Waterways, East Hardwick, Canada) in the fastest time possible. During GXT and TT performance, tidal volume, respiratory rate, ventilation and VO2 were continuously sampled and analysed every 15 s using a Powerlab 8M metabolic system and Chart 5 (AD Instruments, Castle Hill). Power output and heart rate were also measured as indicators of performance effort. Results were reported as mean ± SD, repeated trials were compared via two-way ANOVA's (group x trial), reliability was assessed via intraclass correlation coefficients (ICC) and within participant variability was assessed via mean bias ratio with associated 95% ratio limits of agreement (95% LOA). Results: Male GXT exhibited significantly greater peak power output (Ppeak), tidal volume, ventilation and VO2peak than both female GXT and female TT (p<0.05) with no difference reported between female groups. Overall, there were no significant differences in peak physiological responses or Ppeak between trials, nor was there any interaction effect (group x trial). The mean difference between trial peak values was not significantly different between groups. Significant ICCs were present for all peak physiological responses and Ppeak with values indicating moderate to high reliability (0.74 – 0.97). The mean bias ratio (with 95% LOA) for all peak physiological responses and Ppeak ranged between 0.974 – 1.009 (1.03 – 1.22) with respiratory rate, tidal volume and VO2peak demonstrating the greatest variability of all parameters. Discussion/Conclusion: While repeated VO2peak assessment for arm crank and outrigger ergometry resulted in similar peak physiological responses and moderate to high reliability (ICC) between trials, the 95% ratio LOA for these responses indicated large within-subject variability. The greatest variability was exhibited for respiratory based parameters (respiratory rate, tidal volume and VO2peak) possibly as a result of respiratory entrainment1 during upper body exercise. Due to the large within-subject variability, multiple assessments of peak physiological responses may be necessary for accurate determination of VO2peak during upper body exercise.
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Publication Name
3rd Australian Association for Exercise and Sports Science Conference and the 5th Sports Dietitians Australia Update
Volume
2008
ISBN/ISSN
978-0-646-48582-9
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1
Location
Melbourne, VIC, Australia
Publisher
Australian Association for Exercise and Sports Science
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Publisher Location
Australia
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