What is the Afterburn Effect?
The afterburn effect is calorie burn AFTER exercise. The afterburn effect—technically called “excess post-exercise oxygen consumption” (“EPOC”) – is the scientific term for the afterburn effect, which can help you burn more calories long after you’ve left the gym. The more intense the exercise, the greater the afterburn effect. For example, sprinting as fast as you can for 30 seconds for 5 rounds will have a much larger afterburn effect compared to jogging for 30 minutes. However, new evidence indicates that there is a direct correlation between the intensity of your workout and the amount of calories you burn during an exercise session — and long after. Although there is no equation to calculate your afterburn, there are certain exercises that will give your metabolism a long-lasting boost.
EPOC represents the oxygen consumption above resting level that the body is utilizing to return itself to its pre-exercise state. The physiological mechanisms responsible for this increased metabolism (all chemical reactions in the body to liberate energy that is measured by oxygen consumption) include the replenishment of oxygen stores, phosphagen (ATP-PC) resynthesis, lactate removal, and the increased ventilation, blood circulation and body temperature above pre-exercise levels. Studies have found that the magnitude (amount of elevation in oxygen consumption) and duration (length of time the oxygen consumption is elevated) of EPOC is dependent on the intensity and duration of exercise. It generally takes anywhere from 15 minutes to 48 hours for the body to fully recover to a resting state. Other factors influencing EPOC include training status and gender.
How Afterburn Works
Intense physical activity – including hyperthermic exercise– creates an oxygen deficit. The afterburn effect, also known as excess post-exercise oxygen consumption, occurs when your body continues to burn calories after you exercise to replenish oxygen stores in the muscles while you are recovering. This process increases your metabolism, which is also marked by an increase in blood flow, as your body regulates its temperate back to a pre-exercise state. The more intensely you work out, the longer your body takes to recover. The afterburn effect can help people burn calories to lose weight and reduce body fat if they create a calorie deficit by eating fewer calories than they burn.
Calories You Could Burn
Amy A. Knab of Appalachian State University and a team of researchers set out to determine how many calories a person can burn after a vigorous workout. Ten men recruited for the study performed a vigorous 45-minute workout on a stationary bike. The participants managed to burn 420 calories during the workout. The afterburn effect was measured in a metabolic chamber for over 14 hours, which revealed that the participants burned an additional 190 calories. According to Claude Bouchard, the author of “Physical Activity and Obesity, Second Edition,” people who run or cycle at 70 to 75 of their VO2 — volume of oxygen consumed exercising at maximum capacity — can burn between 300 to 700 calories after exercising. Bouchard also notes that an afterburn of 700 calories is rare.
What is Energy Expenditure?
Energy expenditure is the total amount of calories you burn. More specifically, energy expenditure refers to the amount of energy a person uses during all bodily activities from movement, to blood circulation, to breathing, to digestion. When it comes to exercise, energy expenditure is the total measure of calorie burn during and after exercise.
What is Aerobic vs. Anaerobic Exercise?
Aerobic exercise is a type of activity marked by long distances and slow paces like running, or cycling. Anaerobic exercise is marked by activities that require strength, speed, and power like weight lifting, or sprinting.
Energy Expenditure From Exercise: 3 Components
While total energy expenditure is the sum of the following 3 components, the Afterburn Effect is the sum of #2 and #3 components:
1) Calories Burned During Exercise (O2) – This is the amount of calories you burn during a workout. A metabolic cart can accurately measure you calorie burn aerobically during exercise. This is because oxygen uptake (how much oxygen your body uses) is proportional to heat expenditure (calorie burn) for aerobic activities. This component is NOT part of the afterburn effect.
2) Calories Burned AFTER Exercise (EPOC) – At higher exercise intensities, oxygen uptake is NOT proportional to heat expenditure. An oxygen debt is created, where EPOC (excess post-exercise oxygen consumption) is used to help restore the body to a resting state and adapt it to the exercise just performed, which requires energy. This component is part of the afterburn effect.
3) Lactic Acid Contribution of Exercise – EPOC is NOT enough to fully account for anaerobic contribution of exercise to total energy expenditure. This is a VERY important point and what differentiates Chris’ research. Chris has proposed that by measuring blood lactate reasonable estimates of rapid glycolitic ATP turnover are available and should not be omitted from the estimation of energy expenditure from anaerobic exercise, especially when anaerobic contributions are large. This component is part of the afterburn effect.
The Afterburn Effect Can Be BIG
Energy Expenditure component #2 is typically referred to as the “Afterburn Effect”, when it should really be #2 and #3. The afterburn effect is minimal for traditional cardio, but can be significant for strength and power related activities. In a recently published study (1), Dr. Christopher Scott proposed that as much as 95% of the calorie cost of intense exercise can come AFTER the exercise is performed!
(1) Scott, Christopher. “Misconceptions about Aerobic and Anaerobic Energy Expenditure.” Journal of the International Society of Sports Nutrition 2.2 (2005): 32–37. PMC. Web. 7 Mar. 2016.
APL (American Performance Labs) is a research group dedicated to the collection, analysis, and dissemination of published research and articles on the science of hyperthermia and the various applications, technologies and protocols for the use of hyperthermic conditioning.