Resistance training conserves fat-free mass and resting energy expenditure following weight loss.
OBJECTIVE
To determine what effect diet-induced approximately 12 kg weight loss in combination with exercise training has on body composition and resting energy expenditure (REE) in premenopausal African-American (AA) and European-American (EA) women.


METHODS
This study was a longitudinal, randomized weight loss clinical intervention, with either aerobic (AT), resistance (RT), or no exercise training (NT). Forty-eight AA and forty-six EA premenopausal overweight (BMI between 27 and 30) women underwent weight loss to a BMI<25. Body composition (densitometry), REE (indirect calorimetry), maximal oxygen uptake (VO2max), and muscular strength (isometric elbow flexion) were evaluated when subjects were in energy balance.


RESULTS
AA women lost less fat-free mass (FFM, P<or=0.05) (47.0+/-4.6 to 46.9+/-5.0 kg) than EA women (46.4+/-4.9 to 45.2+/-4.6 kg). Regardless of race, RT maintained FFM (P<or=0.05) following weight loss (46.9+/-5.2 to 47.2+/-5.0 kg) whereas AT (45.4+/-4.2 to 44.4+/-4.1 kg) and NT (47.9+/-4.7 to 46.4+/-5.1 kg) decreased FFM (P<or=0.05). Both AT and NT decreased in REE with weight loss but RT did not. Significant time by group interactions (all P<or=0.05) for strength indicated that RT maintained strength and AT did not.


CONCLUSIONS
AA women lost less FFM than EA women during equivalent weight losses. However, following weight loss in both AA and EA, RT conserved FFM, REE, and strength fitness when compared to women who AT or did not train.
Hunter
Gary R
GR
Department of Human Studies, University of Alabama at Birmingham, Birmingham, Alabama, USA. ghunter@uab.edu
Byrne
Nuala M
NM
Sirikul
Bovorn
B
Fernández
José R
JR
Zuckerman
Paul A
PA
Darnell
Betty E
BE
Gower
Barbara A
BA
D000328:Adult; D001741:Black or African American; D001823:Body Composition / Q000502:physiology*; D015992:Body Mass Index; D001835:Body Weight / Q000502:physiology; D003131:Combined Modality Therapy; D004038:Diet, Reducing; D004734:Energy Metabolism / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D053580:Muscle Strength / Q000502:physiology; D009765:Obesity / Q000208:ethnology / Q000503:physiopathology / Q000628:therapy*; D010101:Oxygen Consumption / Q000502:physiology; D010809:Physical Fitness / Q000502:physiology; D012146:Rest / Q000502:physiology*; D015431:Weight Loss / Q000502:physiology*; D044465:White People