Jade Teta ND, CSCS
Weight loss is not the same as fat loss. You may be burning calories or losing weight, but there is no guaranteeing those calories and that weight loss has come from fat. Unless, of course, you are doing resistance training. Unlike aerobic exercise, which burns both fat and muscle, resistance training pushes energy usage towards fat loss exclusively. It is a little known fact among the exercising public, but weight training has several mechanisms that make it ideal for fat burning. One of which is the ability to target fat loss to specific areas, like the belly. As a matter of fact, weight training should be the chosen modality among exercisers attempting to lose belly fat.
Calories and Fat loss
In order to lose weight, you need to burn calories. But in order to ensure that the weight lost is fat, you need to change hormones. This is why weight training is so powerful at burning fat and why it is especially beneficial for belly fat. In order to understand how this works, you need to know a little bit about the physiology of fat.
On every fat cell there are receptors. These receptors are like little keyholes and when they are opened they turn on all the cellular machinery needed to release fat from its storage compartments. The keys that open these receptors are hormones. When it comes to belly fat there is a certain class of hormones that is most important. These hormones are called catecholamines and include adrenaline. When adrenaline docks to its receptor on a fat cell, it sets into motion a host of physiological processes that burn fat and decrease muscle loss.
You can burn as many calories as you want, but if you don’t stimulate the release of adrenaline, you are going to be less efficient at burning fat. This is why slow plotting aerobic exercise just does not cut it. Intensity is the only way to turn on the release of adrenaline and high-intensity weight training is great at making this happen.
As it turns out, belly fat is very rich in the type of receptors that adrenaline reacts with. These receptors are called b-receptors. Since belly fat is so rich in b-receptors, it would make sense that adrenaline would be able to drive fat burning in this area in a very efficient way, and it does. However, this is not the only way weight training excels at burning belly fat.
Lactic acid and Human Growth Hormone (HGH)
Intense weight training and adrenaline release go hand and hand. However, the belly busting effect of adrenaline’s action on b-receptors is only the beginning of the story. When adrenaline is released in the body, it sets into motion a hugely powerful metabolic cascade that delivers the ultimate in fat burning and muscle building.
When adrenaline is released, in addition to burning fat, it also causes the release of blood sugar. When sugar is burned during high-intensity activity where oxygen becomes limited, the body will switch to anaerobic metabolism. This is where sugar is burned without oxygen and lactic acid is created as a byproduct. Most people think of lactic acid as metabolic waste, but it is actually a signaling molecule. As lactic acid levels build up, it triggers the release of HGH and testosterone. These two hormones are two of the most powerful fat burning and muscle building hormones known and they have special action on belly fat. HGH opposes the fat storing action of cortisol at the belly, and testosterone leads to the production of greater numbers of b-receptors in belly fat. The synergistic actions of these two hormones provide enhanced burning of belly fat during exercise and also make it more susceptible to fat loss at future exercise sessions. And because of their action on cortisol, they make it less likely to accumulate fat in the first place.
A recent study out of East Carolina University and published in Volume 102 of the Journal of Applied Physiology demonstrates weight training’s ability to burn belly fat both during and long after the workout is over. Subjects in this study had probes inserted in the subcutaneous fat around the belly. These probes stayed in place before, during, and 45 minutes after exercise. The participants did a full body resistance-training workout that consisted of heavy weights done for 3 sets of 10 reps using several full body exercises. At the end of the study, researchers found that resistance training increased the usage of abdominal fat during exercise and for at least 40 minutes after exercise. Another similar study published in the 2005 journal Diabetologia Vol. 48 showed 3 months of resistance training in obese men drastically improved fat breakdown at the belly through stimulation of b-receptors. And two earlier studies done in the 1980’s, one in the journal Medicine and Science in Sports and Exercise (vol 16) and the other published in the International Journal of Sports medicine (vol 8), showed that resistance training drastically increased adrenaline release when compared to endurance exercise of equal energy expenditure.
Finally, a recent study shows that resistance training done only twice per week can stop the typical age related fat gain around the middle. This study was funded by the NIH and was presented at a 2003 meeting of the American Heart Association. 164 obese women were followed for two years. One group was told to do 30 minutes to one hour of aerobic activity every day and the other group entered into a structured weight-training program twice per week. At the end of the study, the aerobic group had a 21% increase in belly fat while the weight trained group only had a 7% increase. While much of these results can be explained by lack of adherence, the researchers highlighted the fact that twice per week weight training was very well tolerated and accepted and had a major impact on age related belly fat accumulation.
Weight training is often seen as a good way to build muscle, but is rarely seen as a viable fat loss modality. However, scieince is quickly showing aerobic exercise is unable to provide some of the same fat loss benefits as resistance exercise. In order to burn belly fat, aerobic exercise and resistance training should be combined, but weight lifting should be the primary activity. When it comes to belly fat, resistance training should be a priority.
**Note from the ME Team**: Did you know Dr. Jade has an ebook on Belly Fat? He collaborated with Dr. Ray Hinish of www.cuthefatpodcast.com to put his entire clinical experience on belly fat into a complete system. If you want more on the details presented in this blog plus a ton more, get the book at www.beatyourbellyfat.com