When you exercise, the body utilises energy. Post workout, when the body is returning to homeostasis or a steady state, through cooling down, which can take several hours, there’s an excessive demand for oxygen. This process is called excess post-exercise oxygen consumption (EPOC), which also requires calories.
By working out, you are setting the stage for keeping the calories burning throughout the day, thanks to EPOC or afterburn effect.
Afterburn effect and its impact
While working out the body begins to warm up. The breathing rate and cardiac output increases. There’s also an increased rate of metabolism, lactic acid production and increased CO2 expulsion. After workout, the body enters the recovery period in which EPOC plays an important role in returning the body to homeostasis.
“After a workout the amount of oxygen consumed or the demand for oxygen increases,” says Gautam Sangappa, a fitness consultant and founder of Proton Fitness Academy, Bengaluru. “The oxygen consumed is excess because it is required for dissipating the lactic acid, carbon dioxide and other metabolites and by-products produced during the workout. Depending on how intense and how long the workout is, the body would take time accordingly to attain homeostasis.
The body continues to consume more oxygen for several minutes or hours post-exercise, burning calories in the process.”
Type of exercises and their effect on EPOC
The type of exercises – aerobic, resistance training, plyometrics – play a major role in determining how long EPOC or afterburn effect lasts.
“High intensity interval training exercises, plyometric exercises, heavy resistance training exercises cause the muscle to break down while creating an acidic environment. This increases the duration of EPOC,” says Sangappa. “MetCon or metabolic conditioning are exercises where you are juggling different kinds of high intensity exercises and weightlifting. Circuit training and even high intensity cardio when done in intervals are great for EPOC.”
There are two other parameters that affect EPOC, the predominant one being the intensity of the exercise while the other is the duration of the exercise.
The impact of intensity, duration on afterburn
The intensity of the exercise impacts how significant the EPOC or afterburn effect will be.
“Low intensity exercises bring about EPOC, but at a very low level,” says Sangappa. “Moderate intensity exercises are a little better compared to low intensity exercises. High intensity is extremely good for EPOC. But there is a caveat. High intensity exercises cannot be recommended for everybody. Just because EPOC is good and is great for fat loss, not everyone should be doing high intensity exercises for triggering EPOC.”
The exercise sessions have to be longer to have significant EPOC.
“So, if the intensity is high and the duration is longer, then EPOC can last for several hours. But if the intensity is low and the duration is less, it lasts for a few minutes,” adds Sangappa.
As much as the idea that one can burn calories throughout the day might be appealing, experts advise keeping a tab on the intensity of the workouts and not to push to an extent that can harm the body.
Takeaways
- Afterburn effect, also called EPOC (excess post-exercise oxygen consumption), is required to bring the body back to the homeostasis level or the state it was before workouts.
- Energy is required to attain homeostasis and thus calories are burnt during the process. If the individual has a calorie deficit, it can lead to weight loss.
- The length of EPOC or afterburn effect depends on the intensity and type of exercise.
