Date of Award

5-2012

Degree Type

Report

Degree Name

Master of Science (MS)

Department

Health, Physical Education, and Recreation

First Advisor

Dennis Dolny

Abstract

Purpose: This study investigated whether running on a land treadmill (TM) at specific inclines corresponded to an equivalent metabolic cost (MC, oxygen consumption, VO2) using water-jets on an aquatic treadmill (ATM) at equivalent running speeds. Methods: Sixteen participants completed two trials on separate days on a TM and ATM. For each trial subjects performed eighteen, 3-4 min submaximal runs at three self selected speeds (slow, medium, and fast) with either water-jet resistances of 0-100% of maximum jet flow capacity in 20% increments during ATM or inclines of 0-10% in 2% increments during TM. Trials were separated by at least 48 hours. Oxygen consumption (VO2), heart rate (HR), and rating of perceived exertion (RPE) were recorded during each trial. Regression and 2x6 ANOVA analysis was employed to evaluate TM and ATM running speed x jet resistance/incline relationship. Results: When running at similar speeds with no resistance (jets or incline), ATM yielded lower VO2 than TM. Adding 40% jets during ATM matched MC during TM at 0% incline. At 60% jets ATM MC simulated TM MC while running on a 4% incline. Comparable MC was observed during ATM 80% jets and 8% TM incline, while ATM 100% jets yielded greater MC than TM 10% incline. While TM yields a linear increase in MC with increasing incline, ATM yielded a non-linear, cubic, in MC with increased jet resistance. Conclusion: The relationship between MC and resistance settings in ATM is quite different than TM incline and may be a result of non-linear application of drag forces on the torso created by the water velocities of the water jets.

Comments

This work made publicly available electronically on April 12, 2012.

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