When juxtaposed with same-aged peers, medical students registered comparable rates of compliance with aerobic exercise guidelines laid out by the Centers for Disease Control and Prevention (CDC), research shows. Medical students, however, were far less likely than age-matched peers to engage in the highest-intensity physical activity that is associated with lower stress levels.
The study collected over 1,000 questionnaires from medical students across two years at the University of California, Los Angeles (UCLA), David Geffen School of Medicine and found that health-enhancing physical activity (HEPA) was associated with lowest levels of stress. About one-quarter of students in the study achieved that level, a figure that was 37 percentage points lower than that of their same-aged peers, says the study, published in the journal Medical Education Online. The additional intensity of exercise required to achieve HEPA was associated with markedly lower stress levels among students.
“The biggest takeaway for students is that the CDC aerobic exercise guidelines may engender complacency in exercise habits, since someone who is only moderately active meets CDC guidelines,” said Richard Leuchter, MD, a clinical instructor at UCLA who was the study’s lead author. “While finding time to exercise can be incredibly difficult during medical training, to get the greatest psychological and physical benefits of exercise requires going beyond moderate activity to health-enhancing physical activity, which a majority of medical students were not doing.”
The study’s findings point to the need for a more granular measurement of physical activity than what has long been the standard, Dr. Leuchter said.
CDC guidelines on physical activity look at individual compliance based on the number of total minutes a person engages in on a weekly basis. The World Health Organization has adopted an instrument called the International Physical Activity Questionnaire that further breaks down what the CDC considers “sufficiently active” into moderate physical activity and HEPA. The additional groupings revealed that medical students engaged in significantly less HEPA than national age-matched peers.
Medical students participating in the study whose exercise reached the HEPA classification had a 26% increase in the probability of being in the lowest stress quartile and a 22% decrease in the probability of being in the highest stress quartile.
The formula for achieving HEPA allows for flexibility in duration and frequency of workouts, but three days of just over 60 minutes of vigorous activity, four days of just over 45 minutes and five days of just over 35 minutes, should help students reach the HEPA level, Dr. Leuchter said. Even if participants weren’t able to achieve the highest exercise intensity benchmark, the study found there was still an association, albeit weaker, between moderate physical activity and lower stress levels.
“We did see that as you moved up each physical activity level, such as from inactive to moderately active, there was about a 30% decrease in the odds of being in the highest-stress quartile,” Dr. Leuchter said. “That does not prove that exercise causes lower stress levels but does show some association.”
Medical students who are already working out but aren’t maximizing their aerobic intensity have done the hard part of finding the time for physical activity. When pondering how one can elevate the level of effort exerted, Dr. Leuchter urged students to follow their passions.
“For some people, the most successful approach is figuring out an activity that you're excited about,” Dr. Leuchter said. “Going to the gym or going on runs doesn't work for a lot of people because you don't get that excitement—it feels like a chore to do after class.
“If you replace it with something like rock climbing, tennis, dance, intense yoga, or pickleball, those are activities you can get more excited about, and the more excited you are, the more likely you are to fit it in to your busy schedule,” he added.
Dr. Leuchter also said an all-or-nothing approach to exercise isn’t prudent, particularly considering the lack of bandwidth that medical students have.
“We’ve all been in training and understand it’s not easy to find time and motivation to do these things,” he said. “Some exercise is always better than none, even if you don’t make it to the highest level of activity.”