What is better – High and low intensity exercise?

Hard and low to moderate intensity exercise are each beneficial for burning fat and increasing one’s fitness level. During exercise, we burn combinations of carbohydrate and fat, depending upon the intensity and duration of exercise, as outlined below.

What are the benefits of low to moderate exercise?
At rest, the body uses approximately the same amount of carbohydrate and fat for energy. However, when we begin to exercise whilst the body burns a high proportion of carbohydrates, we burn more fat than at rest. During low intensity exercise, more fat is burnt during the workout when compared to hard sessions. Low intensity exercise is also useful for recovery purposes.
Fat burning during a workout increases as time progresses. As the body is able to store 50 – 100 times more fat than carbohydrate, after approx. 30 minutes of continuous exercise, fat becomes far more available to use, as the body attempts to preserve its small carbohydrate stores. Therefore, to maximise fat burning you should do aerobic exercise for up to 90 minutes.

What are the benefits of hard exercise?
Hard exercise causes you to continue to burn more energy long after the session has finished, whilst the metabolism returns to rest quickly after low intensity exercise. Further, it improves your fitness level, which leads to more efficient fat burning during future workouts and throughout the day. Hard exercise also causes you to burn a higher % of carbohydrates, which promotes carbohydrate depletion. This may prevent any excess carbohydrates that you eat from being converted to fat. Also, the total amount of fat utilised is not significantly less than that burnt in a low intensity session over the same time period. We recommend that you do up to 3 hard sessions per week. All other sessions should be performed at low to moderate intensity.