The Effect of Moderate Physical Activity on Resting Fat Oxidation

The purpose of the study was to investigate the effect of moderate physical activity (following the CDC/ACSM recommendation) on the resting level of fat oxidation. It was hypothesized that a 30-minute treadmill walk at 50% VO 2peak performed in late afternoon would not increase fat oxidation the following morning (12 hours after the end of the treadmill walk). It was also hypothesized that a 60-minute treadmill walk at 50% VO2peak performed in the late afternoon will increase fat oxidation the following morning (12 hours after the end of the treadmill walk). Twenty healthy sedentary women (age 30--47) walked for 30 and 60 minutes on a treadmill at about 50% VO2peak. The respiratory quotient (RQ) was measured first thing in the morning on three occasions: following a day without physical activity (baseline), following a day with a 30-minute walk, and following a day with a 60-minute walk. RQ significantly decreased from .81 at baseline to .79 after the 30-minute walk and to .78 after the 60-minute walk. The RQ difference between the 30- and 60-minute walks was not significant. In 7 participants, RQ did not decrease after the walks; those non-responders had a lower baseline RQ than the other participants. Of the study variables, only caloric intake was positively and significantly associated with RQ. The results indicate that a 30-minute bout of moderate activity is sufficient to significantly increase resting fat oxidation and supports the recommendation of the CDC/ACSM.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Kinesiology and Community Health

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Copay, Anne Ghislaine

Contributors dc:contributor

• Richard A. Washburn

• Biology, Animal Physiology

Language dc:language

eng

Identifier

(MiAaPQ)AAI3070281

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/86361