William Brodegard and Dr. Roy Pat Vehrs, Exercise Science
In early March of last year I was suffered a stress injury from riding a bicycle. I had been training heavily, and was forced to stop training to allow my body to heal. During my time off of the bike, I stayed in shape by running and swimming. When I returned to the bicycle, I found that my level of fitness and biking ability had not depreciated as much as I had thought it might. Cross training had proven effective in maintaining my cycling skill level. I decided to research how cross training and cycling specific training effect the ability of a cyclist to perform in a certain race.
The benefits of cross training and specific training have been extensively studied. Cross training is used to help athletes avoid stress-type injuries such as mine, and prevent burn out, while specific training is used to develop muscle memory and train an athlete for a specific type of exercise. In essence, when an athlete switches from specific training to cross training he exchanges high performance for injury prevention. However, the level of performance sacrificed by cross training has not been satisfactorily researched.
My research compared two groups of cyclists over an eight week training period. Each group consisted of three trained cyclists, and was required to exercise at prescribed levels of intensity for ten hours a week. The first group was asked to cycle, swim and run while the second group was required to cycle only. At the end of the eight weeks the two groups would be evaluated and the performance differences would be compared.
Designing the experiment proved challenging. In order to produce accurate results, all of the variables besides the training method had to be nearly identical for each athlete. My mentor and I decided to test the athlete’s ability to complete a time trial based on their individual VO2 max – a measure of how efficient they are at processing oxygen. The time trial would be performed on an ergonomically braked stationary bicycle, which means that the resistance increased as the athlete pedaled harder. The cycle generated electricity, and once a preset number of joules had been generated the time trial was over. In our experiment, the cyclists had to perform the equivalent of 70% of their VO2 max for an hour. During the time trial, the athlete would know the amount of joules they had generated, but not the time elapsed, pedaling rate or heart rate.
I selected the two experimental teams from a group of friends who had been cycling together over the summer. The cyclists divided themselves into groups based on personal preference and completed the VO2 max. Then they completed a preliminary time trial to set a baseline. Once the time trial was completed they were given a schedule to follow, and began training. After eight weeks the cyclists were again evaluated and the results of the two groups were compared.
The preliminary results of the experiment have shown that in general, the cycling specific group completed the second time trial faster than the cross training group. This result was expected, given the performance benefits of specific training. However, further examination of the results is necessary to understand the percentage decrease in performance, and to identify any confounding variables – unforeseen influences in the experimental design.
Setting up and running the experiment was very difficult. Before beginning the experiment, I had to submit for IRB approval, a necessary step in ensuring participant safety. I had originally planned on performing the experiment in the summer, when cycling would be easy and the cyclist’s schedules relatively free. Unfortunately, due to delays in the IRB approval, I was unable to begin the training until the fall semester. Although the cyclists were able to continue the training even through classes, the added load and stress of exams may have added another variable to the experiment.
Additionally, while all of the cyclists fulfilled a basic fitness requirement, some of the cyclists were highly trained at the beginning of the experiment, and were unable to maintain that level of fitness when the semester began. Cyclists who were not so trained did a better job of maintaining their fitness level throughout the semester. The disparity between fitness levels may also have contributed an unforeseen variable.
In order to complete the research, more work needs to be done. My mentor and I have submitted the data collected for review by a statistician, and will prepare a poster presentation for the annual meeting of the SWACSM (Southwest Chapter of the American College of Sports Medicine) Meanwhile I will prepare articles for publication in Bicycling, Runner’s World and Triathlete magazines.
Overall, this was an excellent experience for me. I was able to experience firsthand the process of designing an experiment, and work closely with my mentor to examine the data collected. The experiences that I have had while completing the ORCA project have been a capstone for my college career.