One of the key questions we get asked a lot by endurance athletes is whether it’s better to use sports supplements such as energy bars and gels or natural foods such as bananas and raisins to help refuel during exercise. Everyone has their own preferences but more often that not, the decision is made on cost, function, taste and convenience.
A relatively recent publication in the Journal of the International Society of Sports Nutrition (Too et al., 2012) investigated the effects of supplementation with raisins (31 g providing 24 g carbohydrate) compared to sport chews (3 Clif blocks providing 24 g carbohydrate) during an 80-minute treadmill run followed by a 5 km time trial. The authors measured the whole shebang in terms of metabolic, performance and gastrointestinal effects of each supplement.
Previously no performance differences have been detected between the use of different types of sports products such as fluid, gels, beans, bars or chews. Therefore the rate at which carbohydrate is delivered does not differ between fluid, semi-solid or solid forms. One of the important factors with using natural or whole foods is the added fibre that can cause gastrointestinal discomfort and slow the rate of delivery of the carbohydrate.
Results from the study by Too and colleagues (2012) demonstrated that a natural food product such as raisins had a similar performance effect to a commercial sports product. In addition, despite being relatively fibre-rich, raisins had a similar gastrointestinal effect as the sports chews. Although, it was noted that there was an increase in the incidences of belching after the ingestion of raisins!
Just one word of caution before you start heading down to your local supermarket to stock up on raisins, you should be aware that the subjects in this study stopped exercising whilst the carbohydrate supplement was administered! One very small but significant point. You may find running whilst chewing on raisins a little more challenging than using a sports gel or bar. Perhaps give it a go and let us know how you get on!