There are two recent articles that I would like to share.  Quite often a new approach will permeate the cycling scene and others just accept that it works because some athletes that are really good are using the approach.  A lot of times the athletes that are good will be good no matter what they do, so it is really hard to make a judgment purely on that basis alone.  Until a controlled study is done, we never really know how well a new approach works.  Below I will highlight two studies using rationale and results directly from the published paper.  I will include the reference in case anyone wants to read the publication.  


Paper 1 – Gluten free diets:  Lis, D., Stellingwerff, T., Kitic, C. M., Ahuja, K. D., & Fell, J. (2015). No Effects of a Short-Term Gluten-free Diet on Performance in Nonceliac Athletes. Medicine & Science in Sports & Exercise.


Background: Previously the authors of the current paper performed a survey of 942 non-celiac diseased athletes and found that 40% used a gluten free diet at least 50% of the time.  The reason for the gluten free diet was often a self-diagnosis of gluten intolerance.  The athletes surveyed believed that a gluten free diet would provide a healthier diet, increase exercise performance and decrease GI distress and inflammation.  The problem with a gluten free diet is that it could result in dietary deficiency if not accompanied by other changes.  To date, no study has actually examined if adoption of a gluten free diet enhances exercise performance as commonly believed.  


Study design: Thirteen competitive cyclists (male and female) free of celiac disease enrolled in a double-blind, placebo controlled, cross-over design.  The subjects consumed a control or gluten free diet for 7 days prior to performance testing with a 10-day washout period between diets.  A dietitian controlled and monitored all aspects of the study.


Results:  There was no difference in parameter associated with performance in a 15 km TT.  There was no difference in GI symptoms during the 7-day periods or during the exercise performance test itself.  There was no difference in overall well being during the study period.  Finally, there was no difference in markers of gut inflammation or systemic inflammation.


Take home:  Although only 5-10% of the general population has a diagnosis of celiac disease, a survey indicated that over 40% of athletes have adopted a gluten free diet.  Results from this study indicated that adoption of short-term gluten free diet did not improve exercise performance, gut inflammation, systemic inflammation, or overall well being.  Of note, although the diet in this study was only employed for 7 days, clinical studies indicate that true gluten intolerance is apparent hours to days after consumption of gluten.  Therefore, this study does not support a positive benefit of a gluten free diet in athletes that do not have celiac disease.  


Paper 2 – Vercruyssen, F., Easthope, C., Bernard, T., Hausswirth, C., Bieuzen, F., Gruet, M., & Brisswalter, J. (2014). The influence of wearing compression stockings on performance indicators and physiological responses following a prolonged trail running exercise. European Journal of Sport Science, 14(2), 144–150.


Background:  Although less prominent in the cycling scene, compression socks are heavily used in running and triathlon.  Studies to date have consistently failed to demonstrate a performance benefit for the exercise bout or the subsequent recovery from that bout of exercise, despite athletes’ reporting that the socks make them feel better.  The current study added to the current literature by examining a trail-running bout of exercise of high intensity and long duration to simulate competition.  In addition, the course had uphill and downhill sections that are not possible to capture in a laboratory setting.


Study design:  Eleven trained experienced male trail-runners were recruited for study.  The subjects took part in both laboratory (for characterization) and field-testing.  The subjects performed familiarization trials of the course prior to the experimental trials.  The subjects completed 3 laps of a course with uphill and downhill segments for a total of a 15.6 km run for each trial.  Data was collected in less than 40 sec between laps to get performance during the exercise bout and at the completion of the test.


Results:  There was no performance benefit (run time) when using compression stockings.  In addition, there was no benefit of the compression stockings on heart rate response, rating of perceived exertion, muscle oxygenation, or maximum voluntary contraction.  


Take home: As with other studies, the current study failed to demonstrate a positive effect of compression stockings when worn during a race-paced running effort over a 15.6 km course.  Interestingly, the study failed to decrease the ratings of perceived exertion as well, which is counter to the subjective “they make me feel better” reports.  This experiment does not support the use of compression stockings during competition.