EPOC stands for Excess Post-Exercise Oxygen Consumption it is also referred to as afterburn or oxygen debt and is increased when we exercise thereby increasing our intake of oxygen following a workout.
Think of it this way. Your body is a machine and when we switch that machine on during exercise it starts to burn fuel; usually carbohydrates. However, when we stop the machine continues to burn energy which therefore requires oxygen and more calories even if your body is in a state of rest. This effect is EPOC and is the amount of energy required to restore the body to its own resting metabolic state or (BMR)Basal Metabolic Rate. It is known as homeostasis. The BMR is the number of calories required to simply keep the functions of the body working, for example digesting food or breathing. We each need a basic number of calories simply to sit still and continue to exist. EPOC is what happens to the increased fuel requirements of the body after exercise and is, as you’d expect, greatest immediately after the workout, however some studies suggest that this effect can last up to 24 hours or more. Therefore, understanding this phenomenon can be hugely useful when planning our training sessions and setting goals.
So how do I use this knowledge and what are the benefits to me?
This is one of the many goals we wish to attain. We all know that weight gain is a major contributor to ill health so the ability you lose fat and keep that weight and fat down is super important to most. Interval training in particular High Intensity Interval Training (HIIT) is something most of us are aware of and is highly effective way to stimulate EPOC. Short bursts of sustained high intensity activity cause the body to use lots of energy and burns calories. This energy is provided by anaerobic pathways as these pathways are quicker. Anaerobic (oxygen free) exercise uses glycogen (carbohydrates that are largely stored in the liver) as fuel in the absence of oxygen. To be specific when energy is needed at a rate that exceeds the ability of the aerobic (oxygen driven) metabolism. Anaerobic exercise is short and intense and can last in burst of up to two minutes.
Increased lean muscle mass.
Let’s talk about weight or resistance training. Progressively increasing those training loads or shorter recovery times increase the demand on the anaerobic system when we exercise. Focus on form and maintaining this form for the entire duration of the set is key.
Adding shorter rests between sets means that the muscles that are being targeted are never quite fully recovered from the previous set. The purpose of emphasising the full control of the muscles being targeted is the muscles are going to be under tension for at least 50 seconds. During this time the muscle fibres are going to sustain micro tears. These, micro tears will need repaired which is why our reliance on protein is so hugely important. Add to this the care and time to stretch the muscles post workout will not only heal those torn muscle fibres more quickly but make them stronger than before. This is why you find that your ability to increase the loads you lift; each session better than the last.
What does EPOC look like and how will I know I am achieving it?
Increased heart rate after the workout
Being out of breath
Sweating profusely post exercise
An increase in your appetite after training.
The features above are all signs that your body is working to cool you down and re-establish your body’s equilibrium.