The Truth About The Afterburn Effect


Training for fat loss? Want to burn more calories in less type? If so, you might be tempted to try HIIT and other high-intensity workouts. According to experts, these training methods generate the so-called afterburn effect, which accelerates fat loss and raises energy expenditure. However, the opinions are mixed. Some say that the afterburn effect is overrated. Let's find out the truth!

What Is EPOC?
EPOC, or the afterburn effect, stands for Excess Post-Exercise Oxygen Consumption. When you're working out at high intensity, your body uses more oxygen than usual. This afterburn effect lasts for hours or even days post training, so you'll keep burning calories. Research indicates that most people burn about five calories for every extra liter of oxygen consumed during HIIT, full body circuits, and other challenging workouts.
Think of your body as a car engine that stays warm after being turned off. The more your intense your workout, the more oxygen you consume and the higher your energy expenditure. Basically, you will consume to burn calories for hours after leaving the gym. This metabolic state is known as EPOC. The afterburn effect depends on a number of factors, such as the type of exercise, workout intensity, and training duration. Running on the treadmill as fast as you can for 10 minutes will require more oxygen compared to jogging or power walking for half an hour.

Recent studies have found that training intensity has a greater impact on EPOC than the length of the workout. When you do HIIT, your heart rate and body temperature increase. At the same time, your muscle glycogen stores are depleted. After training, your body burns extra calories to restore oxygen levels in the muscles and blood, transport lactic acid, and replenish glycogen stores. This process can last for up to 48 hours.

Many gym goers exercise every other day to keep their metabolism up and make EPOC last longer. However, this isn't necessarily the best approach. High intensity training puts a lot of stress on the body, so you need adequate rest. Fitness pros actually recommend a maximum of three high intensity workouts per week. Overtraining elevates the stress hormone cortisol levels, which may lead to muscle loss. Additionally, the body adapts to exercise and begins to burn fewer calories.

EPOC: Myth or Magic Bullet?
Without doubt, the afterburn effect is real. However, research shows that most people only burn up to extra 15% calories after intense training. EPOC is not a magic bullet that will melt away fat and transform your body overnight. Some experts recommend high-intensity workouts lasting up to one hour, which is a big mistake. Most gym goers are barely able to do HIIT for 20 minutes. On top of that, training at high intensity for 60 minutes is mentally draining. Unless you're a pro athlete, it doesn’t make sense to push yourself to extremes just to get leaner.

The afterburn effect can be obtain through HIIT, interval training, circuit training, and weight training with short rest periods. Multi-compound movements, such as the deadlift, lunges, squats, pull-ups, and bench press, require more energy and oxygen, causing your body to work harder to replace the ATP (adenosine triphosphate) lost during training. In other words, heavy lifting increases EPOC and boosts your metabolism. You can get similar results with HIIT, which is the fastest way to stimulate the afterburn effect.
EPOC contributes to your daily energy expenditure, leading to faster weight loss and increased endurance. However, you still need to eat clean. High intensity training can not compensate for bad eating. After all, you'll only burn an extra 50-200 calories due to the afterburn effect. If you drink a 400-calorie latte afterwards, you're doing it all wrong.


  • EPOC, also known as the afterburn effect, is a metabolic state where your body continues to burn calories for up to 48 hours post workout. 
  • The afterburn effect largely depends on workout intensity. 
  • Both HIIT and strength training can trigger the afterburn effect. 
  • EPOC is not a magic bullet to fat loss. To reap its benefits, you need to watch your diet and commit to regular exercise.