Cycling

There are a number of cycling endurance events that take place over several days of competition. The Tour de France is notable for its extreme endurance demands on participating athletes, and each stage of the race places different physiological demands on the cyclists. They pedal approximately 4,000 kilometers over 3 weeks with only a single day of rest allowed! The energy expenditure ranges are the highest values ever reported for athletes over a period longer than 7 days.⁵⁸ The cyclists consume approximately 62 percent of their energy from carbohydrate, 15 percent from protein, and 23 percent from fat. More than 49 percent of total energy consumption takes place between meals. Some days have long hard hills, while other days have roads that are more level. Studies of Tour de France cyclists indicate that they consume approximately 30 percent of their total daily energy intake in the form of a liquid carbohydrate-enriched beverage.⁵⁹ So much time during the day is spent on the bike, there is perhaps no other way to adequately consume sufficient energy.

There may be a connection between cycling and asthma. In studies of athletes at the 1996 Olympic Games in Atlanta, U.S. athletes participating in cycling and mountain biking had the highest prevalence (45 percent) of asthma.⁶⁰ By contrast, 20 percent of the total U.S. team reported they had asthma. This suggests that asthma may be a contributing factor in determining the sport an athlete selects to participate in. For some athletes, it is possible that asthma might be triggered by an allergic response, and this could be an allergic response to food. Cyclists with asthma should be extremely careful about avoiding foods or other substances that could trigger an asthmatic response.

Cyclists suffering from asthma must monitor their food intake carefully because certain foods may trigger an attack.

Keeping this in mind, cyclists must consider the following nutritionally relevant factors for their sport.

Recovering from multiday events. The energy cost of multiday cycling events is enormous, and the meal planning of the athlete's team may make the difference between winning and losing. There is a clear requirement for carbohydrate, which conflicts with the huge requirement for energy because of carbohydrate's relatively low energy density. Although fats have a high energy density, they are not needed to the degree that carbohydrates are. Therefore, large amounts of carbohydrates should be consumed frequently, with the focus on starchy carbohydrates (e.g., pasta, bread, rice, potatoes).

Consumption of food and fluid during long rides. Cyclists have an advantage over other endurance athletes in that they can more easily carry fluids and foods on the bike frame or in jersey pockets. Since there is less bouncing while riding than while running, cyclists can consume solid foods without experiencing GI distress. Cyclists should take advantage of this on long rides by bringing along sports beverages to drink and some crackers, bananas, carbohydrate gel, or bread to eat. These high-carbohydrate foods should be well tolerated and can significantly boost the carbohydrate delivery to working muscles.

Training is very time and energy consuming. The longer athletes train, the more energy they need, but the less time available to them to consume it. Therefore, cyclists should consider the training period as a time to take in a proportion of their daily caloric requirements. To do this, cyclists should find foods that are well tolerated, such as bananas and crackers, and bring them along during the ride. Sports beverages are also an important source of energy, so these should be consumed instead of plain water as a rehydration beverage. A failure to eat during training will inevitably lead to inadequate energy consumption and a decrease in performance.

Endurance athletes spend many hours training and have enormous energy needs. However, these training times make it difficult to consume the needed foods. Athletes should plan multiple eating breaks throughout the day (consuming something high in carbohydrate every 3 hours) to ensure an adequate total energy consumption. Fluid intake is also critically important, and endurance athletes should develop the habit of drinking frequently (every 10 to 15 minutes) regardless of thirst. A large body of evidence suggests that lower levels of either carbohydrate or fluids inhibit endurance. Nevertheless, when high-carbohydrate diets impair an athlete's capacity to consume sufficient energy because of their relatively low energy density, consuming a higher fat intake to help the athlete meet energy needs should be considered.⁶¹ Except to satisfy energy needs, however, fat is not the most desirable energy substrate for endurance athletes.

Carbohydrate after exercise stimulates muscle protein synthesis more favorably than an equivalent amount of fat, so athletes should be careful not to consume fats at the expense of carbohydrates.⁶² Under certain circumstances, caffeine ingestion coupled with adequate hydration and regular carbohydrate intake may aid endurance performance.⁶³ However, because some studies raise doubts as to caffeine's effectiveness,⁶⁴ athletes should determine for themselves whether a small amount of caffeine ingested in long-duration events is useful for enhancing performance.