Health: true or false?

The lowdown on carbo-loading

PUBLISHED : Tuesday, 21 April, 2015, 6:28am
UPDATED : Friday, 01 May, 2015, 8:10pm

Can carbo-loading before a race boost my performance?


The straight answer: Yes


The facts: Filling up on carbohydrates, or so-called carbo-loading, is a strategy for many athletes in the days leading up to a big race. This practice is believed to maximise the amount of glycogen stored in the muscles in order to improve athletic performance. It involves substantially increasing the amount of carbohydrates eaten over a few days before an endurance event, while at the same time, reducing activity level to conserve this fuel.

Carbo-loading has been shown to help prevent athletes from "hitting the wall" - that is, dramatically dropping off their original pace towards the end of a race. Its effectiveness depends on a few important factors:


Your race is high-intensity: Unless you are taking part in a race that lasts longer than two hours - such as a marathon, triathlon or cycling competition, or even doing an endurance activity such as hiking - you likely will not reap the benefits.

"Carbo-loading may not increase your actual speed, but it can prevent you from getting to that point where your muscles have depleted all their glycogen stores and start burning fat as energy (after about 90 minutes of strenuous activity). Compared to carbohydrates, fat is a less efficient source of energy," says Sheena Smith, naturopath and clinical nutritionist at the Integrated Medicine Institute. "When your body starts to burn fat for fuel, you slow down."

You eat the right carbohydrates: Avoid processed foods such as bread, pasta, and pastries. Many people have trouble digesting these refined foods . "Our bodies are better at breaking down whole foods, the way nature intended, so I would recommend foods such as potatoes, sweet potatoes, brown rice, quinoa and pumpkin, and snacking on dates, bananas and mangoes," says Smith.

You taper off your training while carbo-loading: This is important before a race so you are not burning off your glycogen stores at the same time. Ideally, about three to four days before a big race, you would stop training and increase your carbohydrate intake. For an event such as a half-marathon, about one to two days of non-training carbo-loading would be adequate, Smith says.

The amount recommended is between 7-10 grams of carbohydrates per kilogram of your body weight.

You eat carbohydrates after you train: It's not enough to just carbo-load a couple of days before a race. You can help maintain your muscles' glycogen stores by consuming a carbohydrate-rich meal within 30 minutes of finishing each training session, says Smith.

"Our muscles are primed at this point to absorb glucose directly to replace lost glycogen. You will bounce back stronger and will be less likely to fatigue in the following training sessions."