Jelly beans among supplements to be studied for effectiveness in improving exercise performance & warding off fatigue during exercise

Researchers from the UC Davis Sports Medicine Program and Nutrition Department are using competitive endurance athletes in a study that will compare the effectiveness of three different forms of carbohydrate supplementation – including jelly beans (sport beans) – versus plain water in improving exercise performance and warding off fatigue during prolonged exercise.

The researchers have recruited 16 competitive endurance cyclists and triathletes to examine the effects of the carbohydrate supplements. In addition to the jelly beans, the supplements to be studied are sports drinks and gels.

Although a variety of factors contribute to fatigue during prolonged exercise, it is believed that low blood glucose levels can play a role. The ability to exercise for long periods of time also depends on the ability of the cardiovascular system to deliver fuel and oxygen to the exercising muscle and the ability of the metabolic machinery to convert fuel sources into energy. When exercise continues for longer than one hour, the amount of stored carbohydrate in the muscle and liver begins to deplete and blood glucose levels drop. Carbohydrate supplementation provides an additional fuel source to sustain activity and preserves the limited carbohydrate stores in the muscle.

Among the carbohydrate supplements available to athletes, drinks and gels are used more often during races because they are easier to digest than energy bars. Previous research has shown that carbohydrate ingestion via sports drinks during exercise can improve endurance by maintaining blood glucose levels. However, the benefits of carbohydrate supplementation via gels or jelly beans have not been investigated.

The UC Davis researchers will compare the effects of carbohydrate supplementation via drink, gel and jelly beans versus water only during an 80-minute period of exercise, followed by a 10K cycling time trial. This activity is similar to a 30K time trial in cycling or the cycling portion of a half ironman triathlon, where athletes maintain a hard pace for the majority of the race, then exert an intense effort at the end to beat their competitors.

The outcomes that the researchers will be measuring are the athletes’ cycling times during the simulated 10K cycling time trial; respiratory exchange ratios; blood glucose, lactate and free fatty acid concentrations; electrolyte balance; and self-reported perceptions of fatigue.

During the study, the subjects will be required to maintain a daily training log, in which they will record waking body weight, heart rate and the type, amount and intensity of exercise. They also will be asked to rest and be well-hydrated the day before all testing and to follow an identical diet (their normal pre-race meals) for 24 hours prior to all test days. In addition, they will be asked to follow the same diet and exercise regimen they have had for the last month for the duration of the study.

The Jelly Belly Candy Co., based in Fairfield, Calif., is funding and supplying the jelly bean carbohydrate supplements (sport beans) for the study.