I was asked recently what to eat during a 24 hour mountain biking race. There is a popular race entitled “The 24 hours of Adrenalin” which is a relay challenge to complete the greatest number of laps of a mountain bike course in 24 hours. Most teams have five members and one lap of the course takes about 1 hour to complete. Team members will usually complete 5-6 laps over the 24 hour period. It can be difficult to decide what to eat and drink before, during and after each lap. Some teams enter for fun and others enter for the competitive challenge. Regardless of the level of competition, there are some sport nutrition do's and don't that will make the physical experience much easier. Many teams will bring a supply of beer to help pass the 3-5 hour gaps between laps. I've even heard of kegs in some team tents. As you might imagine, alcohol and endurance sport do not mix very well. Not only does the alcohol act as a diuretic, it also dramatically slows the time of muscle recovery. If a team is competitive they would be wise to skip the beer and stock their tent with plenty of water, sport drink and fruit. For the more social teams and all those in between, if you must consume alcohol it should be delayed until at least 1 hour after exercising. Muscle recovery is in its peak stages during the 2 hours after hard exercise. To take advantage of this recovery period it is best to consume a quick source of carbohydrate within 15 minutes of exercise. Contrary to popular belief, beer is not a good source of carbohydrate. A better post exercise snack would be chocolate milk, sport drink, bananas, bagels, pasta and sauce, rice dishes, potato dishes or even simply a bowl of cereal. All of these sources of carbohydrate have relatively high glycemic indexes which means the sugars will get right to the muscle quickly. The trick is to find something that you can "stomach" immediately after exercise. Many people feel slightly nauseated after exercise and would do best with a liquid immediately following a hard workout. That is when beverages such as chocolate milk, sport drinks and juices come in handy. A large glass of carbohydrate rich beverage will get the recovery started until the stomach settles and solid food can be eaten. During an ultra endurance event such as a 24 hour race many will underestimate how much they need to eat. An average 1 hour intense bike ride will burn anywhere from 500-1000 calories. Therefore a competitor in the 24 hour relay race, biking for 5-6 hours will need to consume an extra 2500-6000 calories! That is over and above normal resting caloric needs of about 2000 calories per day. In a 24 hour race such as this, there is really no time to waste. You should be either biking, eating or sleeping. It may sound like fun to go wild on high calorie foods however it becomes a challenge to find foods that will digest quickly enough to be out of the stomach before the next shift of exercise. Greasy, high fat foods such as donuts, burgers and sausages are loaded with calories however they take too long to digest for pre-exercise eating. Some high calorie choices that are easier to digest include nuts, crackers, lower fat cheese, dried fruit, pasta, submarine sandwiches, risotto, rice pudding, powerbars, yogourt shakes, etc.
As with any sporting event, it's worth the time to plan out an eating strategy for peak performance. Good luck to all those competing this coming weekend!
Heidi Smith is a Registered Dietitian from the Health and Performance Centre. She is the author of the book “Nutrition for the Long Run - A nutrition handbook for runners, walkers and active individuals”. Her column runs every Thursday