If one of the reasons you signed up for exercise was the thought of guilt-free bowls of pasta (carb loading boosts performance, right?) you better make sure you are working for it. Unless you are planning to go hard for 90 minutes or more, you can step away from the carbonara, says , head of nutrition at the Australian Institute of Sport.
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However, for long workouts, like a big race, it can help. When elite male cyclists doubled their normal carb intake for three days, and their speed by 1.3 kilometres per hour in a 1-hour time trial that followed a strenuous 2-hour ride.
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As a general guide, Burke recommends eating per 24 hours for 1.5 to two days before long, hard events like marathons or football matches.
Glucose-containing sports drinks and gels can give you a top up when your stores start to drop off during very long or intense sessions. But they may also give a boost by activating the parts of the brain that sense when there are carbohydrates in the mouth. 鈥淭hey seem to tell the brain: there鈥檚 plenty of fuel on board, you can keep pushing the body at the highest rate possible,鈥� says Burke.
You could even trick your brain without the calories. Endurance runners who simply rinsed their mouths with a carbohydrate solution at regular intervals during a treadmill challenge .
Then again, amateur athletes should be careful about overdoing their carb consumption, says , a sports scientist at the University of Cape Town in South Africa. He carb-loaded for 33 years to help sustain him through 70 marathons and ultramarathons, but was then diagnosed with type 2 diabetes. He attributes this to excess carbohydrate intake combined with a family history of the disease.
One alternative is to train the body to use fat as a fuel instead of carbs, says Noakes. Eating a low-carb, high-fat diet 鈥� meaning about 5 per cent carbohydrate, 70 per cent fat and 25 per cent protein 鈥� for at least six weeks makes the body better adapted to burning fat, says Noakes. Perhaps counter-intuitively, .
Yet despite the hype surrounding low-carb, high-fat diets, there is no robust evidence that they improve athletic performance. Then again, if you don鈥檛 mind running a marathon at a moderate pace and you don鈥檛 want to carb-load, a high-fat diet could help to keep you going. And if you are trying to lose weight, watch out. People tend to overestimate calories used in exercise and underestimate those in food.
What about post-workout? This is when it is important to eat protein, because it provides the building blocks required for replenishing muscle, says Burke. She recommends eating about 20 grams of protein within 30 to 60 minutes of finishing an exercise session to build new muscle. In addition, she advises including 20 grams of protein in every main meal for the next day or two because your muscles will still be responding to the last workout. 鈥淚f you continue to prime your body with more protein, you鈥檙e going to get the maximum benefit from that session.鈥� Go on, you earned it.
This article appeared in print under the headline 鈥淲hat should I be eating?鈥�
