Why exercising on an empty stomach actually burns more fat

Early gym sesh it is, then. Zzzzzz...

Words by Jadie Troy-Pryde

Whether or not you exercise to lose weight, tone up or feel fit, a new piece of workout-related science has proved very interesting.

According to a new study, getting up and going to the gym in the morning before you've eaten anything could actually be burning a lot more fat than if you decide to get your sweat on after work.

Researchers at the University of Bath looked at the effect of exercise with and without food, and the results are intriguing to say the least. They study took ten overweight men and asked them to walk for sixty minutes at 60% oxygen consumption. First, they did this on an empty stomach, and then again after consuming a carbohydrate-rich breakfast. Researchers took blood and fat tissue samples before and after both exercise sessions in order to analyse any significant differences.

They found that two genes - PDK4 and HSL - both increased when the participants fasted before going for a walk. However, when they had eaten breakfast before their exercise the genes saw a decrease. Therefore the spike in PDK4 and HSL suggests that when someone works out without having lined their stomach with food, they're burning stored fat for energy - rather than what they consumed for breakfast.

It's not the first time that science has suggested fasting before a gym session can be beneficial for fat loss, so if that is your goal it could be worth swapping the after-work classes for earlier ones.

However, it must also be said that the study was such a small one - meaning that we won't feel too bad if we choose to catch extra zeds in the morning instead of sweating buckets in a pre-work spin class.

So just do what feels right for you and your body.