Wednesday, 13 August 2014

Nutritional Practices for Ultra-Endurance Events

Following on from last week’s blog about the demands of ultra endurance events, this week I will start to look at some of the nutritional practices that athletes can apply when training and competing in ultra-distance events.  

Appropriate and consistent training is one of the key factors in ensuring a successful performance in an ultra- distance event and supporting this training with the appropriate nutrition will also ensure that the athlete is ready to give their best performance on race day.

Preparation is also vital for race day success and  thorough planning and organisation when it comes to nutrition will ensure that a compromise is reached between achieving a light pack weight and carrying sufficient and effective fuel for the race.

Hydration

Staying hydrated and replacing fluid lost through sweat is important for not only performance but also for health reasons. Minor levels of dehydration will affect both physical and mental output whilst training and competing. Significant dehydration creates a significant risk of heat stroke and severe dehydration could lead to death.

During the week prior to the competition, the athlete should drink the recommended 2L per day and replace fluids lost through sweat in training to make sure that hydration levels are optimum levels before the start of the race.   

On race day, the athlete should start drinking as soon as they have woken up, and try to consume approximately 500ml before the start of the race.  This will ensure that any small fluid losses overnight are replaced.

During the race, the athlete should aim to replace the fluid lost through dehydration. This will be difficult, as most athletes cannot tolerate large fluid intake, especially in hot conditions.  A good compromise is to limit dehydration levels to less than 2% of the body weight. Measuring sweat rates during training and build-up races, as mentioned in an earlier blog, will help estimate how much they will need to drink.

Athletes should choose a drink which is palatable, not fizzy and, for these events, fluid which provides carbohydrate and electrolytes. This doesn't need to be a branded sports drink; in fact, a home made squash drink with a pinch of salt can be as effective and, for some, more tolerable than a sports drink. 

Carbohydrate

A lot of focus was previously been put on carbohydrate loading in preparing glycogen stores for the race. However, this will occur naturally providing that high carbohydrate intake is consumed alongside a pre-race taper and the focus which was previously suggested is not necessary.

Ultra endurance events often have early starts with minimal time on the morning of the race to get the appropriate nutrition on board. High Carbohydrate, low fat and low fibre foods should be on the list for athletes to eat and at least 100g of carbohydrate is a good amount to aim for to top up glycogen stores. Good examples include white bread jam sandwiches, cereal bars, breakfast cereals, bananas and fluids such as fruit juices, soft drinks and sports drinks. To facilitate rapid gastric emptying and nutritional absorption food should ideally be consumed 3-4 hours before race start.  Closer to the start of the race (1hr), a further carbohydrate snack will help prevent decreases in blood sugar levels during the early section of the race.

During the race, muscle and glycogen levels will normally last between 60-90 minutes, before the body needs to turn to other energy sources. At this point, the athlete is unlikely to maintain the same output and is sometimes known as hitting the wall. Maintaining carbohydrate levels during the competition will help the athlete to maintain output for longer.

The recommended intake is 1g of carbohydrate per kg of body weight per hour, and can be consumed in a variety of forms. For most athletes this will mean an intake of at least 50gms of carbohydrate every hour. Common sources include sports drinks, gels and bananas, but, during the latter stages of longer distance events, sandwiches and more savory snacks are common choices.  The following foods contain 30-60g of carbohydrate:
  • 500ml fruit juice or soft drink 
  • 500ml Sports Drink  
  • Sports or Energy Bar
  • 2 handful of sweets or dried fruit
  • 4-6 Jaffa Cakes
  • Cereal Bar
  • 2 Carbohydrate Gels
Food choices will often depend on the race provisions, athlete preferences and the ability to transport them during the event, all of which should be researched and practiced during training, and preferably a test race. Athletes must also have a 'plan b' just in case things don't go to plan on race day, or the athlete suffers stomach discomfort.

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