Do We Need More Carbs Before A Sporting Event? Or Will Fat Give Us Enough Energy? A Research Review

Hi everyone, I’m Ashleigh D’Arcy, one of the Dieticians here at Destiny Health! The relationship between fats, carbohydrates and energy in sports has always been a fascinating topic for me.

Every client of mine has unique needs and can therefore benefit from a personalised program. However, below is a summary of what I have found in the scientific literature (references below). I use this knowledge in my everyday work, guiding people to optimal results.   

It’s important to acknowledge that both fat and carbohydrate have been found to be the main fuels for aerobic metabolism (which means using oxygen for energy) during exercise in well-fed people.

We must also remember that the body can turn fat into carbohydrate in a process known as gluconeogenesis (“creating new glucose” in the bloodstream).  

Interestingly, fat has been found to be the dominant energy source at low aerobic power outputs (< 40% VO2max) and provides approximately 50% of the required energy during moderate intensity exercise (~40-65% VO2max).

The contribution from fat decreases at higher power outputs, as carbohydrate is seen to be the main fuel in these instances.

Fat oxidation (breakdown with oxygen) has been found to contribute energy during recovery from a single bout of exercise, and in recovery periods between intense exercise bouts (common in stop-and-go sports). This means that fat is burned after exercise to help us recover. 

Activation of fat oxidation at the onset of exercise is slower than carbohydrates. So, fat appears to be designed for long-term, low to moderate intensity exercise.

Carbohydrate needs seem to vary, depending on the length and intensity of the sporting event. This may be as high as 10-13 grams of carbohydrate per kilogram of body weight per day for endurance sport athletes.

A 60 kilogram athlete participating in a 1-1.5 hour gym session may safely consume 60-90g of carbohydrates before their training session, whilst a 60kg athlete performing a 2-3 hour cycling session would benefit more from 180-240g of carbohydrates prior to the session, to ensure adequate energy levels throughout the race.

A few examples of 50g carbohydrate food/ drinks include:

500ml of fruit juice

50g of jellybeans

1 cup of cooked rice

3 pieces of medium fruit

If your goal is increased performance in a 90 minute gym session, the research suggests that 500ml of fruit juice before hand will aid your performance.

What are your specific goals? And does this information help you in your sport?

At Destiny Health, our team of Dieticians take a deep dive into your lifestyle, history and goals, to customise the ideal program for you.

If you’re busy juggling training and career goals, if you want to gain THE EDGE in your performance, and if you’re SERIOUS about results, then why not register your interest in a FREE ASSESSMENT today?

Simply call 1300 GYM DOC (1300 496 362).   

Ashliegh : )

B.Nut.Diet (Hons), APD


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