Science and Technology
A lot has changed in the last year. I have left Colorado Springs and relocated to Albuquerque, NM to finish my doctoral studies at the University of New Mexico. I am studying under Dr. Rob Robergs who is heading-up my doctoral committee. For those of you who are not familiar with Rob, he did much of the early research on the use of glycerol as an ergogenic aid. Though I continue to collaborate with researchers at the Olympic Training Center, I am performing new research centering on how the body creates new mitochondria (mitochondria are those little organelles that provide most of the energy athletes use during exercise). Finally, I am continuing to perform research on hyperoxic training. Much of this work is being done to bring this exceptional training method to athletes who do not have access to the Olympic Training Center.
I will continue to update this page of the website with my own research and other works that are pertinent to exercise training, so check it often.
-Dave
Former World Champion Matt Kelly is tested in the U.S. Olympic Committee's Exercise Physiology Lab. This testing will determine maximal oxygen consumption, lactate threshold and maximal steady state power output. The results can be used to prescribe training intensity and monitor the progress and efficacy of a training program
Recent Research Projects
Optimal Crank Arm Length
The debate over optimal crank lengths and how to predict optimal crank arm length for a particular cyclist has gone unresolved many years. Traditional beliefs have held that optimal crank arm length increases with an increase in a rider's leg length and thus, proper crank arm length can be determined by the length of a rider's legs. To determine the validity of this belief, Dave Morris performed a research study that investigated the effect of crank arm length on cycling efficiency and the effects of leg length on optimal crank arm length.
During the project, competitive cyclists completed 3 different tests by riding at a consistent power outputs while using crank lengths of 165, 170 and 175 mm. Oxygen consumption (a measure of efficiency) was collected during each trial and was used to determine each subject's optimal crank length. Each subject was required to complete a two-week habituation period during which they rode 225 km per week on each of the three crank lengths before being tested on that crank length.
The results of the study demonstrated that crank arm length did affect economy and that optimal crank length does vary from one individual to another. However, no relationship was found between each subject's optimal crank length and his leg length. Thus, it does not appear that optimal crank arm length can be determined by a rider's leg length.
Reference:
Morris, D.M. & B.R. Londeree (1997). The effects of bicycle crank arm length on oxygen consumption. Canadian Journal of Applied Physiology, 22(5): 429-438.
Living High, Training Low
Since the staging of the 1968 Olympics at altitude in Mexico City, athletes and coaches have had an increased interest in altitude training. Many research and practical experiences have demonstrated that exercise performance can be improved by increasing the oxygen carrying capacity of the blood, and that exposure to moderate and high altitude environments can improve the blood's ability carry oxygen. These results have prompted many cyclists to incorporate altitude exposures into their training program.
Altitude training is not without its drawbacks, however. The decreased oxygen availability in altitude environments requires athletes to decrease their training intensity during altitude exposures. This reduction in training intensity inevitably leads to detraining. Thus, the positive effects of the increased oxygen carrying capacity of the blood are often offset by the negative effects of detraining and as a result exercise performance usually does not improve after altitude exposures.
In a recent research project, Dave Morris worked with fellow scientists from the US Olympic Committee in an attempt to develop a new method of altitude training that would allow athletes to gain the positive effects of altitude exposure without experience the negative effects of detraining. To do so, competitive cyclists were recruited from sea level environments and transported to the moderate altitude environment of Colorado Springs, CO where they lived at the Olympic Training Center for three weeks. During this three-week period, half of the subjects performed nine interval training sessions while breathing normal air, and the other half performed identical intervals while breathing oxygen-enriched air that simulated sea level conditions.
The results showed that those subjects who breathed the oxygen enriched air were able to train at higher power outputs than those who breathed the normal air. Furthermore, the subjects that used the oxygen-enriched air significantly increased their maximal steady state power output and significantly improved their time trial performance as opposed to the subjects breathing normal air who showed no improvements in these areas.
Reference:
Morris, D.M., et. al. (2000). The effects of breathing supplemental oxygen during altitude training on cycling performance. Journal of Science and Medicine in Sport, 3(2): 165-175.
Other Research with Supplemental Oxygen
Due to the initial success of using oxygen enriched air, Dave continues to work with the U.S. Olympic Committee to develop training programs that utilize supplemental oxygen. Thus far, these training programs have been used by many of the country's top cyclists, triathletes and long track speed skaters. The recent success of several long track speed skaters at the Olympic Games in Salt Lake City supports the efficacy of this training method.
Professional cyclist Michael Creed performs intervals in the laboratory at the US Olympic Training Center in Colorado Springs while breathing a gas mixture containing 60% oxygen. Normal air contains 21% oxygen. This increased oxygen content allows Mike to increase his training intensity by about 15% and leads to a greater training effect. Note the use of the SRM to apply the proper training intensity and monitor power output.