Our bodies are specifically designed to expend as little energy as possible. Obviously, if your ultimate goal is fat loss, this results in a problem because in this case, you want to be expending as much energy as possible. When the goal is body fat reduction, the key is to focus on burning more calories, not necessarily burning fat. It’s also important to understand that one must expend more calories than consumed in order to lower body fat.
So in order to avoid the body expending minimal energy, you need to focus on expending maximal energy. How do you do this?
Focus on maximizing caloric expenditure in each training session, & thus the excess post oxygen consumption.
EPOC (excess post oxygen consumption) refers to the state in which the body’s metabolism is elevated following a workout. This simply means that the body is burning more calories following exercise than it was before taking part in exercise. A good analogy to compare is to is how the engine of a car stays warm for a period of time after is has been driven. Following a workout, your body is using more oxygen than normal in order to replenish energy supplies, lower temperatures, and return the body to a resting state, resulting in more calorie burn.
Research has shown that the higher the intensity of the training session (the higher the HRmax or VO2 percentage), the greater the magnitude of EPOC. It has also been shown that splitting the training session into multiple sessions (2) of equal time may have the greatest effect on EPOC. This would seen to make sense since the body’s metabolism would be elevated on 2 different counts throughout the day.
I suggest focusing on pushing yourself and increasing the intensity of your workouts a little more than you have been lately. If you do, this will maximize the amount of oxygen consumption needed for the duration of (as well as the recovery from) your workout, as well as result in burning more calories overall!
Reference: NASM: Essentials of Personal Fitness Training