Abstract: Blaize, AN, Potteiger, JA, Claytor, RP, and Noe, DA. Body fat has no effect on the maximal fat oxidation rate in young normal and overweight women. J Strength Cond Res 28(8): 2121–2126, 2014—The purpose of this study was to examine how fat mass affects the maximal fat oxidation rates of women. Fourteen active, healthy women (age, 21–31 years) with body composition ranging from 18.6 to 30.0% fat were divided into 2 groups (15–24.9% = lower-fat group; 25–35% = higher-fat group). On day 1, subjects performed a graded exercise test on the treadmill to determine maximal oxygen consumption (V[Combining Dot Above]O2max). On day 2, subjects were measured for % fat and performed a maximal fat oxidation test. Fat and carbohydrate oxidation rates were determined using gas exchange analysis. Fat oxidation in absolute (in gram per minute) and relative to fat-free body mass (in milligram per kilogram of fat-free mass per minute) was determined using stoichiometric equations and appropriate energy equivalents. There were no significant differences (p > 0.05) in maximal fat oxidation rates between the women in lower-fat (0.39 ± 0.10 g·min−1, 8.52 ± 2.69 mg·kg−1 FFM·min−1) and higher-fat (0.49 ± 0.13 g·min−1, 10.81 ± 2.80 mg·kg−1 FFM·min−1) groups. Maximal fat oxidation occurred at an exercise intensity of 55.7 ± 11.1% and 59.1 ± 5.4% V[Combining Dot Above]O2max for the lower-fat and higher-fat groups, respectively, with no significant difference between groups (p > 0.05). The maximal fat oxidation rate (g·min−1 and mg·kg−1 FFM·min−1) was not significantly correlated with any of the descriptive variables (fat mass, fat-free mass, percent body fat, or V[Combining Dot Above]O2max). In conclusion, personal trainers and health practitioners can use the exercise intensities that elicited the highest rate of fat oxidation to prescribe exercise programs to women, despite their body composition, that prevent weight gain and/or promote body fat and body weight loss.
1Department of Kinesiology and Health, Miami University, Oxford, Ohio;
2Department of Movement Science, Grand Valley State University, Grand Rapids, Michigan; and
3Department of Statistics, Miami University, Oxford, Ohio
Address correspondence to Dr. Jeffrey A. Potteiger, email@example.com.