Subcutaneous fat alterations resulting from an upper-body resistance training program.
OBJECTIVE
It is believed spot reduction, the exercise-induced localized loss of subcutaneous fat, does not occur as a result of an exercise program; however, evidence as a whole has been inconsistent. To reexamine this concept, we compared subcutaneous fat measurements before and after resistance training among 104 subjects (45 men, 59 women).


METHODS
Subjects participated in 12 wk of supervised resistance training of their nondominant arm. Magnetic resonance imaging and skinfold calipers examined subcutaneous fat in the nondominant (trained) and dominant (untrained) arms before and after resistance training. Repeated-measures ANCOVA tested for subcutaneous fat differences within and between arms before, after, and from before to after resistance training by gender and measurement technique, with BMI and age as covariates. Simple linear regression compared subcutaneous fat changes before and after resistance training as assessed by MRI and skinfold.


RESULTS
Subcutaneous fat, measured by skinfold, decreased in the trained arm and not the untrained arm in the men (P < 0.01); it was similar in the total sample and in the women (P > 0.05). MRI determinations of subcutaneous fat changes were not different between arms in the total sample and by gender (P > 0.05).


CONCLUSIONS
Subcutaneous fat changes resulting from resistance training varied by gender and assessment technique. Skinfold findings indicate that spot reduction occurred in men but not in women. In contrast, MRI found a generalized subcutaneous fat loss independent of gender, supporting the notion that spot reduction does not occur as a result of resistance training. MRI, sensitive to changes along the entire upper arm, detected greater variation in resistance training responses, preventing significant differences between trained and untrained arms. Variation in upper-arm resistance training response was not evident from a single skinfold measurement at the belly of the muscle.
Kostek
Matthew A
MA
Department of Kinesiology, University of Connecticut, Storrs, CT 06269-2101, USA. Matthew.kostek@gmail.com
Pescatello
Linda S
LS
Seip
Richard L
RL
Angelopoulos
Theodore J
TJ
Clarkson
Priscilla M
PM
Gordon
Paul M
PM
Moyna
Niall M
NM
Visich
Paul S
PS
Zoeller
Robert F
RF
Thompson
Paul D
PD
Hoffman
Eric P
EP
Price
Thomas B
TB
D000328:Adult; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D018482:Muscle, Skeletal / Q000254:growth & development; D012885:Skinfold Thickness; D050151:Subcutaneous Fat / Q000502:physiology*; D014481:United States; D034941:Upper Extremity / Q000473:pathology*; D014891:Weight Lifting / Q000502:physiology*