I read a very cool little review in the May 2007 issue of Muscular Development on page 116. It summarized a Danish study that concluded spot reduction does actually work. As a former Personal Trainer at Equinox in New York City, it was an inevitable conversation that you had to have with every client - spot reduction does not exist; your body has a natural pattern of fat distribution and it will lose weight in the reverse order in which it gains weight. Ultimately, diet is what determines your body composition - you can't out-train a poor diet. But, after all these years, it does seem that targeted exercises may actually help burn fat in a given area.
Here is the article summary as it appears in MD, May 2007 issue:
Danish Scientists Showed That Spot Reducing Works!
For years, scientists told athletes that spot reducing doesn't work. For example, you can't lose arm fat by doing curls and triceps extensions. These conclusions were based on volumetric studies that estimated changes in lean mass and fat in the arms and legs following weeks of specific exercises in those areas. Danish researchers, led by Dr. Bente Stallknecht from the Panum Institute in Copenhagen, showed that spot reducing is effective. Researchers used radioactive tracers (133Xe) to measure changes in fat mass during high-rep knee extensions, which is more sensitive than measuring density changes in the arms and legs. Researchers also studied blood flow and fat breakdown in fat tissue adjacent to working muscles and in fat tissue around inactive muscles in the other leg. After 30 minutes of doing knee extensions with one leg, subjects switched legs and did knee extensions for 120 minutes using more weight. Blood flow and fat breakdown were greatest around the working muscles. The study researchers concluded that specific exercises could cause "spot reducing" because blood flow and fat use was higher in adipose (fat) tissue adjacent to working muscles. Spot reducing was most effective at higher intensities because it generated more heat in the muscles and triggered a higher release of catecholamines (fight-or-flight hormones, such as adrenaline). This was an exciting study for bodybuilders that overturned longstanding beliefs about spot reducing. The take-home message is that spot reducing works. High-rep, high-weight exercises reduce local fat stored best. (American Journal Physiology Endocrinology Metabolism, 292: 394-399, 2007)