It’s true that when you exercise more regularly and stay the same way you eat or improve it slightly, you’ll burn fat and lose weight, so running 5Ks to burn fat is a good start.

Depending on the length and difficulty of your workout, your body will generally use carbohydrates (stored as glycogen in the muscles and liver) and fat as a fuel source. And from this, your body will select a different ratio of these fuels for various types of exercise.

Fats contain more calories per gram (9 kcal) than carbohydrates (4 kcal) and take longer to convert to energy, so they tend to be used for anything that is slower in nature and longer in duration. As your fitness levels improve, you’ll become a fat-burning machine, while conserving more glycogen stores… You’ll burn more fat.

When exercise becomes more intense, the body uses a much higher percentage of glycogen and less fat, although this does not mean that higher intensity training will not burn fat. However, there is a big misunderstanding about this. Since running at a lower intensity will rely on the use of more fat than glycogen, doesn’t this mean that to burn maximum fat you need to run at a slower pace and for longer?

Well, when we talk about burning fat, we basically mean using and burning more calories than we eat and consume. When we exercise, the intensity level we work at will also dictate how many calories we burn and where these calories come from, so the higher the intensity level, the more calories used for fuel. Basically speaking, a higher percentage of calories from carbs but also more calories from overall fat.

So the secret to running 5k for fat burning is to do a mix of slow and steady training and shorter but higher intensity sessions to get the best fitness improvements but also burn more fat.