Effect of a sports food bar on fat utilisation and exercise duration

The manufacturer claims that using the Access Fat Conversion Activity Bar increases fat utilisation, which would have a glycogen-sparing effect and delay the onset of fatigue from endurance exercise. This claim was tested using seven trained distance runners who performed two trials of treadmill running at 73% of VO2max to exhaustion. In a counterbalanced design, subjects ingested either one Access Bar with water or water only prior to treadmill running. Times to exhaustion for the control and Access treatment trials were 104.6 +/- 24.9 min and 93.9 +/- 21.4 min, respectively, and were not significantly different (p > .05). Differences between trials were not observed for the respiratory exchange ratio, blood lactate or glucose concentrations, plasma glycerol concentration, or perceived exertion. Based on results from this study, it was concluded that the Access Bar does not affect fat or carbohydrate utilisation and does not improve exercise endurance.