The study was conducted by researchers at the University of New South Wales and published earlier this month in Medicine & Science in Sports & Exercise. For their research, scientists recruited 24 healthy but inactive individuals. 12 of the people said they were inactive but were interested in exercising, while the other 12 said they preferred not to exercise.
After the groups were separated they each were put through similar tests to create a baseline pain threshold. This involved putting pressure on a person’s arm until they said the pressure went from unpleasant to painful. Researchers later put individuals through a second pain threshold test, this time asking users to squeeze a device while a blood pressure cuff tightened on their forearm until it became too painful.
After their pain threshold was documented, participants interested in exercise undertook a moderate stationary bike workout three times a week, for six weeks. Researchers noted an improvement in fitness levels as cycling workloads increased each week. The other group continued with their lives as they had prior to the study.
Both groups returned to the testing lab six weeks after the study first began. Volunteers not interested in exercise showed no changes in their pain threshold, but participants in the exercise program saw a noticeable spike in pain tolerance. They experienced pain at the time point they had during the initial test, but they were able to withstand the pain for much longer at the end of the program.
“To me,” said Matthew Jones, lead researcher of the study, the results “suggest that the participants who exercised had become more stoical and perhaps did not find the pain as threatening after exercise training, even though it still hurt as much.”
Scientists have previously hypothesized that a person’s body will emit opitates, such as endorphins, during exercise to slightly decrease discomfort. This process is known as “exercise-induced hypoalgesia,” and usually occurs during a workout and lingers for about a half hour after the workout is completed.
The study didn’t examine the physiological principles at play, but Jones noted that the decision to use a predominately leg-focused workout and an arm-based pain threshold test suggests that “something occurring in the brain was probably responsible for the change.”
If pain is too crippling to begin an exercise regimen, a person may do more harm than good by trying to exercise through the pain, but if you can tolerate even a moderate amount of exercise, you may be able to increase your pain threshold. Consult your doctor if you have questions or concerns.
Related source: NY Times