This summer, 10 cyclists each traveled almost 2,000 miles to take part in a study to determine how sustained fatigue affects the human body. Normally, experiments of this type are performed in a laboratory to provide a controlled environment for studying the results of the stimuli applied to the test subjects. However, thanks to the help of the PowerTap and a 25-foot Airstream trailer, Professor Brent Ruby, Dustin Slivka, John Cuddy, and Walter Hailes of the University of Montana were able to take their study to the streets, literally.
The riders started their 3-week experiment in Missoula, Montana and snaked their way through Montana and Wyoming to Granby, Colorado and back averaging around 100 miles per day. Each metric of their ride was captured by the PowerTap CPU and downloaded each evening. Biological samples including blood, urine, saliva, and muscle, were also collected on a regular basis in their rolling laboratory. Being able to conduct the experiment outdoors on real roads allowed Dr. Ruby to study the stresses that athletes actually encounter when they are riding.
After hearing about the study, we wanted to know more, so we asked Dr. Ruby a few questions of our own.
PowerTap: Where did you get the idea to do this study?
Brent: The concept of the study worked itself into my mind as we were collecting some data on the Lewis and Clark trail between Missoula and Idaho. We were evaluating the effects of extended work on alterations in muscle enzyme adaptations associated with fat use. The idea for the name “Giro D’iscovery” grew out of Montana’s close association with the Lewis and Clark Expedition, the Corps of Discovery and with my love of cycling. The term “Giro D’iscovery” was put together by my lab group during a $1.99 breakfast special one morning at a local restaurant right on the Clark Fork River. Our goal for this study was to build off of our previous field research and go several steps further to answer a series of questions surrounding the ideas of muscle adaptations, overtraining, and ultimately the maintenance of performance.
PowerTap: What were your major goals in doing this study?
Brent: Our research goals for the Giro D were to provide a physiological overload that would create the likelihood of overtraining. We wanted to provide a controlled series of daily physical stress to better evaluate how the body can adapt to intense work and to determine if we could locate any markers associated with fatigue (or a lack of fatigue) in the muscle, blood, urine, and saliva (the big four!). Our other goal for the study was to create a very unique research environment that goes beyond what other labs attempt. We put a great deal of time into the development of the study so as to create the opportunity for major physiological strain outside of the laboratory while providing the necessary elements of experimental control that can be difficult in a field setting. Another side goal was to create a study that took field research to the next level, incorporating several measurement techniques most often reserved for the laboratory world.
PowerTap: How did the PowerTap play a role in your analysis of the data?
Brent: We have used the PowerTap systems in previous research, creating the concept of a “rolling laboratory” to evaluate work output on the road during a nutrition-based study and a time trial project. I had also used the PowerTap during training and racing, most recently during a study we did last October at the 2006 Ironman World Championships in Kona, Hawaii. From my past experience, PowerTap provided the capability to collect real time power output and additional ride data in a way that would make it possible to accurately measure the physical demands of the Giro D. With all the physiological sampling in place, we needed a way to quantify work.
The PowerTap provided us with this capability. Without knowing the work output, it is difficult to determine whether subjects are changing their riding behavior to match any depletion of muscle nutrients or adaptations within the skeletal muscle. Power meters provide an absolute measure of work, watts, which provides a rider/coach/physiologist with the necessary data to objectively evaluate performance.
The capability to accurately measure power during training and race scenarios is as significant to the cycling community as the development of round wheels!
PowerTap: What was the athletic background of the study participants? i.e. were they already avid cyclists?
Brent: The group of riders in the Giro D included Cat 1-2 road cyclists to National Class collegiate and professional triathletes, and cyclocross and mountain bike racers. The group of Giro D riders was almost as diverse as the Corps of Discovery! However, all of our study participants were avid riders. We knew going into the development of the study that our research staff would not be able to counsel inexperienced riders through the psychological trauma of 2000 miles. We also knew that less experienced riders would fall apart in a matter of days from overuse injuries, nutritional depletion, upper respiratory sickness, and overall fatigue.
PowerTap: Were riders allowed to eat as much as they wanted each day or were their calories limited?
Brent: Riders were provided with a near limitless supply of Gatorade Endurance and Gatorade energy bars during the rides. Additionally, riders were provided a full catered breakfast and dinner. It was impressive to see how the riders chose to eat during each day of the Giro D; however, there was not a food shortage at any time. It was very apparent that when these riders chose to eat, drink, and rest adequately, they could tolerate any amount of physiological stress each day. Averaging 5-7 hours of riding a day for the duration of the study, riders began to self-select a higher intake during the ride. The riders consumed an average of 3 liters of Gatorade Endurance and 2 Gatorade food bars each day. Of course there was the occasional stop for coffee and milkshakes here or there.
PowerTap: Were the riders encouraged to treat the ride like a race?
Brent: Not always. The daily rides were completed via a “self-select” intensity. However, when you put a group of male riders on the road and say “go,” some amount of chest pounding is bound to happen. There were occasional breakaways and attacks on climbs. However, much of the “racing” was limited to the scheduled time trials. These were done every third day during the duration of the Giro D. After a warm up, riders were sent off at intervals on a time trial we called the “Hour of Power.” At this time, riders attempted to go as hard as they could across a designated point A to B course, which varied in terrain. Riders were awarded a series of jerseys according to the top performances (yellow – farthest distance in the hour, green – highest absolute average power, polka dot – highest average watts/kg) to better maintain motivation.
PowerTap: What were the most noticeable changes that occurred in the riders over the course of the study?
Brent: The most noticeable changes will likely be a combination of alterations in the skeletal muscle (after we evaluate all 60 muscle biopsies). However, until this is completed, we will not have the complete picture. Interestingly, all of our riders completed the Giro D. We fully expected some dropouts due to a variety of likely causes. However, this was not the case. In general, riders continued to perform well in the Hour of Power. However, there were some unique individual differences among the riders, with some demonstrating an increase in average power across the duration of the Giro D and others showing obvious signs of fatigue. I think even the riders themselves were impressed with how they were capable of completing the three week ride which represented more than a 100% increase in average training volume compared to the months prior. In terms of the laboratory testing, we noticed a major shift in efficiency. That is, at a given power output, there was a decrease in heart rate and oxygen consumption (they were able to work less to maintain the same absolute workload).
Another major change was the rider’s recognition that the measure of real time power output is a phenomenal tool. Often riders feel that data (speed, distance, etc.) takes away from the “purity” of the ride/race. However, these riders now recognize a power addiction that provides the best available tool to monitor performance and adaptations to training.
PowerTap: What were the biggest challenges you incurred during the study?
Brent: As usual with field research, you are faced with the ever-changing environment. At first, I thought the biggest challenge would be the riders themselves. I honestly thought this had all the potential to turn into a 21 day Giro D’babysitting. However, the riders were incredible at maintaining themselves and each other. They were a bit slow and unorganized in the morning (no matter what, it took 1.5 to 2 hours to get them on the road), yet once on the road, they were great.
The science portion of the study and the laboratory equipment and methodologies worked great in the field. The 25-foot Airstream rolling laboratory was a huge asset to the data collection. I think we now hold two world records for total biopsies done and in an Airstream trailer and most biopsies done in one day in an Airstream trailer (both at 20!). Interestingly, the data collection and data handling (via massive excel spreadsheets) worked flawlessly.
PowerTap: Do you have any cool stats from the study?
1995.3 Total miles. 71,632 Total vertical feet of climbing. 5 million Total number of pedal strokes. 378 Total # of Gatorade food bars consumed. 771 Total # of Gatorade Endurance bottles consumed. 60 Total # of muscle biopsies (6 per rider). 20 Total # of muscle biopsies in an Airstream travel trailer (2 per rider). 98.7 Total # of average hours in the saddle (average 5.2 hours/day). 140 Total number of Big Macs associated with the average total energy expenditure during the Giro D (equivalent to 80,000 kcals/person, 4,200 kcals/day, 8 Big Macs/day). 1 Total # of enthusiastic middle fingers from pissed off Lexus drivers.
PowerTap: Would you ever do this again?
Brent: Without a doubt! This was by far the most elaborate field study we have done in or out of our laboratory. The planning and organization was impressive considering how unorganized my own garage is. Funding is the most obvious limitation. However, “Have kick ass Airstream mobile lab will travel” is our mentality. We are also building a new laboratory on the University of Montana campus (The Montana Center for Work Physiology and Exercise Metabolism) – try answering the phone!
Our research objectives are to combine laboratory and aggressive field research models to determine the physiological aspects and challenges associated with human performance in a variety of environments.
PowerTap: When can we see the results of the study?
Brent: The results will be presented at various scientific meetings and will appear in a variety of physiology journals. However, it is also our goal to provide this data in other formats via popular press periodicals, interviews (just waiting for Letterman), and other publications. When is the more difficult question to answer. The data analyses of the muscle and other samples will take months. We hope to present data as it becomes available. However, I am not sure when this will be. Just tuck Giro D’iscovery into your memory banks and be ready.
More information about this study can be found at Dr. Ruby's website.