What Impact Does Exercise Intensity Have on Abdominal Fat Loss?

 

Who doesn’t want to shed a little more fat off the abs? It’s body fat that covers up the ab muscles you’re working so hard to define. However, losing tummy fat becomes harder with age, especially after menopause. It takes a little work in the exercise room AND in the kitchen to expose those sculpted ab muscles. Yes, exercise is an important part of the equation but there are a number of ways to exercise. Exercise helps burn fat, including belly fat, but what role does exercise INTENSITY play in helping you achieve lean, sculpted abs?

Exercise Intensity & Belly Fat Loss 

Belly fat comes in two varieties: subcutaneous belly fat and deep, visceral fat. The deeper form, known as visceral fat, isn’t the jiggly stuff you pinch but a “hidden” form of fat deep in your pelvic cavity. It often shows up as a widening waistline or a muffin top. Of the two, visceral fat is more dangerous from a health standpoint. It’s deep, visceral fat that’s linked with a higher risk of type 2 diabetes and heart disease.

What role does exercise intensity play in shedding tummy fat? In one study, researchers divided 18 overweight, older subjects into groups. One did moderate-intensity exercise at 50% of their V02 max while the other did high-intensity workouts at an intensity of 75% of their V02 max. The participants burned 1,000 kilocalories per week for 12 weeks. Another group, serving as a control, did no exercise.

Before and after the study, the participants underwent body composition testing. Interestingly, the high-intensity exercise group shed visceral fat while the moderate-intensity and control group did not. Body weight, BMI, and fat percentage stayed the same in all three groups. Neither the high-intensity or moderate intensity group lost significant amounts of subcutaneous fat or fat around the thighs. The big difference was the amount of visceral fat they lost.

At least based on this study, high-intensity exercise is best for metabolic health more because it reduces visceral abdominal fat more. Visceral tummy fat is the type of fat most strongly linked to insulin resistance and risk of type 2 diabetes. In fact, waist circumference, a marker for visceral fat, is one of the strongest predictors of insulin resistance. As the researchers in the study point out, high-intensity exercise preferentially targets visceral, abdominal fat.

High-Intensity Interval Training for Belly Fat Loss 

If you’re ready to step up the intensity of your workouts and shed visceral fat, high-intensity interval training is the way to do it. High-intensity interval training (HIIT) lets you exercise at an intensity you would normally not be able to sustain for very long. By alternating periods of very intense exercise with a pre-determined recovery period, your body maximizes workout intensity during the work periods and recovers long enough to do it again. With moderate-intensity cardio, you typically work at 60% to 50% of your maximum heart rate, whereas with HIIT training, you push it closer to 90% of your maximum heart rate during active intervals.

Greater Belly Fat Loss

What about the jiggly, subcutaneous fat that you’re tired of pinching between your fingers? HIIT training may be better than moderate-intensity exercise for generalized loss of belly fat as well. In one study, a group of healthy individuals did 40 minutes of strength training and 20 minutes of cardio. The only difference was one group did 20 minutes of moderate-intensity exercise on the treadmill while the other did 20 minutes of bodyweight interval training. At the end of 8 weeks, the moderate-intensity group lost less than an inch of belly fat. The interval training group? They shed 2 inches around the belly.

How can you explain HIIT training being better for belly fat? Researchers believe it has to do with EPOC, excess post-exercise oxygen consumption. Because HIIT training pushes your body past its lactate threshold, you get more of an after-burn effect. After you’ve completed the last interval, your body has to expend more energy doing things like removing lactate and lowering your body temperature than it does after moderate-intensity exercise. This means you burn more calories even after your workout is complete. Exercise intensity is the primary determiner of how much EPOC you get, with exercise duration being a close second. Research shows EPOC more than doubles when you boost exercise intensity from 55% to 95% of your aerobic capacity or V02 max.

Another reason HIIT training is more effective for loss of belly fat has to do with the stress hormone cortisol. Sustained aerobic exercise can elevate cortisol. However, you don’t want a prolonged release of cortisol since, being a catabolic hormone, it can trigger muscle breakdown and increased belly fat storage. While you release cortisol during a HIIT session too, intense exercise also stimulates the release of anabolic hormones, like testosterone and growth hormone. This compensates for the catabolic effects of cortisol. Those anabolic hormones help you burn more body fat and counteract cortisol.

Other Ways to Boost Belly Fat Loss 

While HIIT training can give you a leg up on losing belly fat, it’s most effective if you combine it with other belly fat burning strategies. Don’t neglect the weights. Resistance training boosts anabolic hormones that help you break down stubborn belly fat. High-intensity strength training with a predominance of compound exercises, like squats and deadlifts, is the most effective fat-burning approach since you’re working multiple, large muscle groups at the same time.

What about your diet? Here are some nutritional strategies that can help:

·       Reduce sugar and processed carbs.

·       Increase the protein content of your diet for satiety.

·       Boost the amount of fiber in your diet.

 

The Bottom Line

If you’re not losing belly fat, add high-intensity intervals to your training. Based on research, it’s more effective for trimming visceral fat than moderate-intensity exercise. That will help your waistline, but, most importantly, your metabolic health.

 

References:

Metab Syndr Relat Disord. 2009 Aug; 7(4): 363–368.

Diabetes Care. 2006 Mar;29(3):673-8.

Med Sci Sports Exerc. 2008 Nov; 40(11): 1863–1872.doi:  10.1249/MSS.0b013e3181801d40.

Journal of Applied Physiology 47: 514–521, 1979.

National Strength and Conditioning Association. “Is EPOC Large Enough to Cause Weight Loss?”

J Obes. 2011; 2011: 868305. Published online 2010 Nov 24. doi:  10.1155/2011/868305

 

Related Articles By Cathe:

High-Intensity Interval Training: How Intense Does It Have to Be?

Resistance Training Versus Cardio: Which Is Best for Reducing Belly Fat?

5 Common Myths About Belly Fat – Busted

 

X