We know of no study to examine the effects of raisins versus commercial GPCR Compound Library sports
products in runners. GI complaints are more pronounced during running, which may be related to the greater mechanical jarring involved [15]. Reports have also noted that 83% of marathoners and 81% of endurance athletes experience some level of GI distress during training or competition [15]. Ingesting a higher fiber supplement in raisins during an endurance run may cause more GI discomfort than eating lower fiber sports products. Therefore, the purpose of this study was to examine the metabolic and running performance effects and GI tolerance of a natural whole food product (raisins) compared to a commercial product (sport chews) and water only. It was hypothesized that the raisins and chews would elicit similar metabolic responses and both would improve running time trial performance over water only, yet because of the higher fiber content, raisins would elicit greater GI discomfort. Methods Subjects Fourteen healthy competitive runners were recruited from the University of California at Davis (UC Davis) campus find more and local venues. Twelve subjects were
needed based on a power analysis (http://hedwig.mgh.harvard.edu/sample_size/js/js_crossover_quant.html) (power = 0.8, significance = 0.05, mean difference (MD) = 0.58 min for performance time of supplement versus water in men only and SD of the MD = 0.64 min) [12]. Three subjects quit during the study before all trials were completed for reasons unrelated to the supplementation (aversion to needles, calf strain, knee pain). Therefore, only 11 of 14 subject’s data were included in the analysis (power = 0.8). Subjects were required to have ran a marathon in <4-hr or completed two half marathons in <2-hr within the past year and run >48 km·week-1. Medical clearance and an informed consent approved by the UC Davis Institutional
Review Board were also required. Training and diet Subjects recorded all training sessions for the week prior to the first sub-maximal exercise test and repeated that same exercise program for the remainder of the study. Subjects were advised to rest or have a light training day prior to all testing days. The subjects’ general diets were monitored by a 3-day 2-hydroxyphytanoyl-CoA lyase diet record completed before the first meeting. 24-hour recalls were completed the day prior to the first sub-maximal exercise trial and repeated exactly for all subsequent trials (Food Processor SQL Version 9.2.0, ESHA Research, Salem, OR). A 240-kcal snack (68% CHO, 16% fat and 16% protein) (Clif Bar, Berkeley, CA) was provided to consume 10-hr before each of their testing times. After the provided evening snack, only water was consumed. Maximal exercise test Subjects reported to the laboratory for their first visit which included a medical clearance examination and maximal exercise test.