Fitness Makes You Better At Burning Fat, New Research Shows

The benefits of burning fat are generally associated with weight loss in our culture, but as athletes we tend to overlook the importance of good metabolism in cardio and endurance performance.

We’ve understood for a long time that athletes using the aerobic system - particularly when participating in events that last a long time such as marathons and ironmans, but also in shorter-duration events - the body depletes its glycogen stores relatively quickly and needs to rely on fat as an energy source.

The more efficient a person’s body is at burning fat to create energy, the longer it typically takes for them to become exhausted and slow down.

Now, physiologists at the University of Bath have looked into the factors that most affect an individual’s ability to burn fat.

They identified two common variables that influence metabolism: gender and fitness.

Having assessed 73 healthy adults between the ages of 19 and 63, they measured key indicators after a cycling test.

They found that females and those with better fitness across all ages burnt fat more effectively when exercising.

While the researchers were unable to explain on a molecular level why women performed better, they discovered a link between the proteins in muscle that are involved in breaking down stored fat into fatty acids and a greater ability to burn fat which seems to explain why fitness is a key factor.

Dr Javier Gonzalez, also from the University of Bath's Department for Health, said: "Weight management is mainly about energy balance, so to lose weight we need to eat fewer calories than we expend through our resting metabolism and physical activity. 

“However, people with a higher ability to burn fat as a fuel seem to be somewhat protected against future weight gain, which might be related to how fat burning affects food intake and energy expenditure.

"Ultimately, a greater capacity to burn fat as a fuel has potential benefits for endurance athletes, by delaying the time point when they run out of precious carbohydrate stores."