Scientific Research on Burning Fat

Scientific research on how your body burns fat helps health and fitness professionals provide better exercise and dietary solutions to help those who are obese or at risk for cardiovascular diseases. At home, understanding how fat metabolizes helps you distinguish between methods based on evidence and those based on pseudo-science and sensationalized claims.

  1. The Approach

    • Scientific research relies on asking questions and forming a theory based on observations and past knowledge. This approach allows scientists to act like detectives to answer seemingly simple questions, such as how your body burns fat. Using this approach ensures that the results of any experiment focusing on the reduction of body fat provides concrete answers that others can rely on and replicate. As a result, scientifically-proven results that focus on how your body burns fat are methods you can reliably adopt into your daily routine.

    Exercise Afterburn

    • Your body doesn't stop metabolizing fat after you stop exercising. Like a car engine that stays hot after driving for an hour, your body undergoes a process called excess post-exercise oxygen consumption in which fat and carbohydrates are used for energy to cool down your body, replenish nutrients to your cells, repair muscle damage and restore your hormones to their pre-exercise state. This process can last between 15 minutes to 48 hours, according to exercise physiologist Len Kravitz. A 2011 study done at Appalachian State University in North Carolina showed that a group of male cyclists who performed 45 minutes of high-intensity cycling sustained EPOC for about 14 hours. Although caloric expenditure gradually decreased over the 14-hour period, the resting metabolic rate remained higher than their pre-exercise state.

    Spot Reduction Myth

    • Doing numerous situps and other strength exercises that target certain body parts won't trim down your excess body fat. Because your body cannot sustain the exercise for a long period of time, aerobic respiration doesn't kick in, and you body remains at an anaerobic state. In a 1984 study published in "Research Quarterly for Exercise and Sport," subjects who participated a 27-day situp program showed no reduction of the size or the number of abdominal fat cells. The fat tissues remained the same as those that are in the body parts that weren't exercised, such as the shoulders and buttocks. However, strength training can induce EPOC like high-intensity aerobics. A 2010 study published in "Journal of Strength and Conditioning Research" showed that doing superset training, which involves performing two exercises that trains different muscle groups without rest in between, elicits a higher metabolic rate after exercise than doing strength exercises one set at a time.

    Go High or Low?

    • Although low-intensity, steady-pace aerobics metabolizes fat, the net amount of fat you burn is lower than high-intensity interval training, which involves performing a bout of high intensity exercise followed by a period of low-intensity exercise. A 2012 study performed at the University of Lethbridge in Alberta, Canada showed that intervals of two-minute sprints produced similar levels of EPOC as 30 minutes of continuous aerobics. In another study published in the June issue of "Journal of Obesity," young overweight men who performed high-intensity interval training had an average of 17 percent reduction of abdominal fat and gained 0.4 kilograms of muscle mass in their legs and 0.7 kilograms of muscle in their trunk. However, if you cannot perform high-intensity training, start with lower-intensity training and gradually progress to higher intensities. Work with a qualified exercises professional for a few weeks if you're new to high-intensity training.