Exercise is the blanket term for a number of different sciences; physics, biochemistry, physiology, neuroanatomy, motor control, psychology et al., The idea of an exercise “expert”, someone equally adept at all sciences is ridiculous, it would take more lifetimes than a cat to be able to accomplish that. We here at Exercise-Intellgence readily acknowledge we don’t and can’t know everything, therefore every month we will reach out to experts in their given field to answer the questions that we can’t so we can all learn a bit more.
This month we reached out to Dr. Fred Dimenna Ph.D., professor of advanced applied physiology and neuromotor adaptation to exercise at Columbia University, Teacher’s College.
1)Is there any new evidence to suggest that "spot reduction" of body fat is possible without some sort of medical intervention?
In 2007, Kostek et al. published research which helped to explain previous ambiguous findings regarding the ability to spot-specifically reduce body-fat stores with exercise. These researchers had 104 subjects perform a 12-week resistance-training program for the elbow flexors/extensors of the non-dominant arm with the dominant arm used as a within-subject untrained control. Results showed that fat loss for the trained muscles did, indeed, occur, but only for male subjects when body fat was assessed by the skinfold technique. Conversely, with MRI assessment of male subjects and with both forms of measurement for females, no fat reduction was registered. Interestingly, males also experienced muscle growth due to the training intervention while females did not. The authors concluded that in addition to changes in subcutaneous fat, skinfold measurements are affected by muscle growth because extracellular space between fat cells is compressed. The take-home message is that when muscle growth is also present, skinfold assessment might suggest that spot reduction has occurred when, in reality, it has (and can) not. Further confirmation comes from a more recent study where Ramirez-Campillo et al. used dual x-ray absorptiometry (DXA) to assess the regional fat changes induced by “endurance resistance training” (unilateral leg press performed three times per week for one set of 960–1,200 repetitions per session). These researchers found that while fat was reduced by ~1.5 lbs. without dietary restriction following the 12-week intervention, fat deposition in the legs did not change. The authors concluded that the fat loss was induced exclusively by the negative energy balance that was present due to inclusion of exercise in the subject’s daily agenda with the site of the loss dictated solely by the initial fat content of the subject’s body regions.
Dr. Fred Dimenna, Ph.D.
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