Runners love pasta parties, and endurance athletes are fuelled by gels and sweets, but do we need to rethink our relationship with carbs for the best performance? Runner and coach, Fiona Bugler and sports nutritionist Lucy Ann Prideaux report.
The movement to ‘train low carb and race high carb’ has gathered momentum in recent years amongst triathletes, cyclists – and even runners! And former carb fans, such as world renowned running expert, Tim Noakes, author of the The Lore of Running have had a complete change of view, saying excess amounts of carbs (especially high GI, sugary and refined carbs), are not good for runners and that sugar and processed food is responsible for the obesity epidemic and shocking rises in diseases such as diabetes (A Diabetes UK report in August 2015 found that there has been a 60 per cent increase in the disease in a decade).
Carb diet options for athletes
So how does the ‘traditional’ endurance athlete’s high-carb diet work? The body will easily adapt to a high-carb diet, becoming highly efficient at metabolizing carbohydrates for energy. In a long run or race for example, a runner may top up with energy-boosting carb gels. If they don’t have gels, they may under perform not because carbs are the only answer, but because their body has adapted to carbohydrate metabolism, burns carbs quickly, and needs regular top-ups. It expects to receive regular amounts of glucose to continue making energy.
The theory goes on that if you train the body to use fat when you run you do not need to be loading up with extra carbs. However, some athletes find that during this transition period, when relying too much on burning fat as fuel it’s harder to move faster or step up a gear, as the body can’t make energy quickly enough, and they run out of juice during training – and catastrophically, on race day. Many opt to ‘train low’ on carbs (50 per cent fats, 25 per cent carbs, and 25 per cent protein) for five to 10 days. Then, one to three days before a race, they opt for carb-loading with 80 per cent of their food coming from carbohydrates, 10 per cent from fat, and 10 per cent from protein, and take carbs on board during the race, i.e. ‘race high’.
We still need carbs – but watch your GI score
Carbs do supply readily available energy for performance but it’s important that the carbs we eat are healthy and we understand that not all carbs are equal. Carbohydrates are ranked using a scoring system called the glycemic index (GI). The GI score of a food is based on the rate at which it breaks down into sugar (glucose), how fast it is absorbed, and consequently how quickly is raises levels of blood glucose.
High GI Carbohydrates breakdown quickly during digestion, and release glucose into the blood very quickly.
Examples: processed ‘white’ foods, pure sugar, and energy gels.
✗Eating too many high GI foods can block the ability to burn fat.
✗High GI foods don’t fill you up and you’ll get hungry again quickly.
✓High GI food can provide fast-energy replenishment or be used during exercise – e.g. energy gels.
Low GI Carbohydrates breakdown slowly, releasing their glucose gradually into the blood stream.
Examples: Apples, pears, plums, oranges, grapefruits, raspberries, blueberries, kiwis, fresh figs; brown rice, wild rice, quinoa, barley, a few wholegrain breads such as dark whole rye bread, soy/linseed bread, and vegetables.
✓Provide longer-lasting energy, and a more sustained feeling of fullness, therefore aid in fat loss.
✓Generally, these foods are higher in fibre and nutrients, too.
The ultimate solution and best diet for athletes, is one that is flexible and includes moderate amounts of healthy carbohydrates balanced with quality proteins and essential fats. During periods of intense training, and leading up to long endurance events, the athlete should increase the amount of carbs, based on their particular energy expenditure, and their response to carbohydrates. Trial and error is necessary to a degree, and eventually the individual finds the perfect amount for them to train, recover, and race successfully.