The Principles of Sports Nutrition for Endurance Runners
Endurance runners have one thing in common… they all do large amounts of training to achieve their personal best!
So what makes one runner better than another if they are all just as fit, disciplined and motivated? Their nutrition! Long-distance runners literally are what they eat in combination with of how hard, but more importantly, how efficiently they train, including how well they recover between training sessions. Performance-enhancing shoes, clothing, and sporting equipment can all be bought at a price, but overall health, energy and performance outcomes can only be impacted by nutrition. Achieving the most suitable body composition can also bring many advantages to an individual’s performance and this again can be manipulated by diet. It is essential that all runners understand the importance of nutrition as well as hydration and put just as much effort into their diet as they do into their training.
Carbohydrate loading is a well-known practice believed to enhance sports performance. There are many proposed theories about the best way to carbohydrate load and this has changed significantly over the years since it was discovered that muscles could actually store more carbohydrates by overloading without having to deplete their stores first. The importance of consuming sufficient carbohydrates prior to competition is to ensure the muscles are primed for energy release and also have sufficient energy stores to continue to function at an optimal level until they are re-fuelled.
Many studies have examined the effect of combining carbohydrates with protein during the pre-competition phase for enhanced performance although this theory has proven ineffective at improving competition performance beyond what can be achieved when comparing the effect of supplementing carbohydrates alone. Alternatively, some studies have shown that a combined carbohydrate and protein intake during this pre-competition phase may enhance muscle recovery by having protein more readily available in the muscle.
The optimal amount of carbohydrate recommended pre-competition varies according to the distance of the race. For marathon runners, around 7-8 grams per kilogram of body weight is recommended per day for 24-48 hours prior to competition with a tapered training load to ensure maximal storage in the muscle. It is important that the triathlete seeks individual dietary advice from an Accredited Practising Dietitian (APD) if they are struggling with achieving optimal body composition and weight management rather than just reducing carbohydrates and energy intake to compensate. Insufficient energy intake may result in persistent fatigue, poor health, and immunity, delayed recovery plus increased risk of injury.
On the day of competition, it is advised to consume 1-2 grams carbohydrate per kilogram of body weight within 1-4 hours of competition and this may either be low or high GI foods depending on the athletes rate of digestion (in combination with nerves) as they may experience stomach upsets so ensure these foods are low in fat and fibre.
Nutrition during Competition
It is important to refuel the muscles during a marathon to prevent ‘hitting the wall’ and this is most easily achieved by using a combination of sports drinks and gels. The amount of carbohydrate required will vary between 30-60 grams of carbohydrate per hour. A Dietitian can help you to plan your race nutrition plan effectively before your event so you can assess your tolerance to food and drinks and still ensure to meet your carbohydrate and fluid requirements.
Nutrition for Recovery
Immediately post-exercise, there is a ‘window of opportunity’ for enhanced recovery by consuming 1-1.2 grams of carbohydrate per kilogram of body weight in combination with 15-25 grams of high-quality protein within one hour of completing exercise. This is when the rates of glycogen and protein resynthesis are greatest although this process may continue for 24-48 hours post-exercise. The types and forms of foods consumed during recovery will depend on athlete’s tolerance, food availability and accessibility as well as the athlete’s overall daily energy requirements. Recovery nutrition provides benefits such as allowing greater body adaptations to train to become fitter, stronger and faster, plus refueling the muscle and liver glycogen stores, repairing muscles, enhancing immune response and replacing fluid and electrolyte losses. Long-distance runners should aim to consume 125-150% of their estimated fluid losses (as determined by weight loss on scales) within 4-6 hours post-competition and include around 50-80mmol/l of sodium to enhance rehydration.
By Kristen Adams – Accredited Practising Dietitian
Ph: 03 9789 1233