Date of Award

Spring 5-9-2015

Degree Type

Dissertation

Degree Name

PhD Health Sciences

Department

Health and Medical Sciences

Advisor

Genevieve Pinto Zipp, Ph.D.

Committee Member

Vincent A. DeBari, Ph.D.

Committee Member

Michael A. Figueroa, Ed.D.

Keywords

lower body positive pressure, fat oxidation, oxygen consumption, obesity

Abstract

Purpose: To determine if a reduction of body weight from 100% to 75% while walking on a lower body positive pressure treadmill (LBPP) affects peak oxygen consumption (V̇O2peak), fat oxidation (FO), peak fat oxidation (PFO), respiratory exchange ratio (RER), heart rate (HR) and rate of perceived exertion (RPE) in overweight and or obese men. Methods: Fourteen, overweight and obese men (mean age 23.2 ± 2.4 years, BMI 36.5 ± 3.8 kg/m2 and Body Fat % 38.6 ± 7.0%) were randomly assigned to walking on the LBPP treadmill at 100% and 75% of their body weight. The protocol consisted 3-minute stages at a constant speed of 3.3 mph for the duration of the test. Percent grade increased three minutes following the warm up from 3% to a maximum of 15%. FO, PFO, RER and V̇O2 were measured using indirect calorimetry. Fat oxidation rates were calculated using stoichiometric equations. Results: Significant differences in V̇O2peak,fat oxidation rates, HR and RER (p t-test, between the treadmill conditions (100% BW and 75% BW). V̇O2peak and HR were higher at 100% BW compared to 75% BW (23 ± 4 vs. 17 ± 3 ml/kg/min, and 157 ± 23 vs. 141 ± 20, respectively). Additionally fat oxidation rates were lower at 100% BW compared to 75% BW (-0.19 g/min vs. 0.04 g/min). PFO occurred at 40% of V̇O2peak (0.22 g/min at 9.21 ml/kg/min) in the 100% BW condition where PFO occurred at 47% to 62% of V̇O2peak (0.23 g/min at 17.69 ml/kg/min and 0.23 g/min at 17.69 ml/kg/min respectively) in the 75% BW condition. RPE was significantly lower at 75% BW compared to the 100% body weight condition (12 vs. 14, respectively). FO rates in the decreased BW condition were observed at a low to moderate intensity (40 to 62% V̇O2peak) which also stayed elevated longer compared to 100% BW. Conclusion: Reducing one’s body weight on the LBPP can be used as a low to moderate intensity exercise for obese individuals as a means to sustain physical activity, improve one’s exercise tolerance resulting in an improved quality of life.

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