All posts by ACSM Blog

Physical activity as possible depression prevention method

By Chad D. Rethorst, Ph.D.

Depression often results in significant economic and health burdens on society. One factor that contributes to this burden is the challenge in successful treatment of depression. Research indicates that nearly half of patients do not respond to initial treatment and one-third remain depressed even after multiple treatment attempts. While this indicates a need for more effective ways to treat people with depression, many researchers are also examining strategies to prevent depression.

In my research, I’ve observed patients with depression whose conditions have improved by following an exercise program as a part of treatment. Now, a recent study published in the American Journal of Psychiatry indicates that exercise may also be one way to prevent depression. The researchers who conducted this study found that 1-2 hours of exercise per week is enough to significantly reduce the risk of depression. People who reported no exercise were 44 percent more likely to be depressed in the future compared to those who exercised for 1-2 hours per week.

While 1-2 hours per week may sound like a daunting goal for someone who doesn’t exercise, so it is even more encouraging that the results suggest that as little as 30 minutes of exercise per week may be beneficial. Also, the researchers found that the intensity of the exercise did not impact the preventive effect. So, one 30-minute walk per week may be enough to help prevent depression.

While the results of this study are encouraging, more research in this area is needed. We need to develop effective interventions to increase exercise among persons at risk for depression and we need to understand the biology of how exercise prevents depression. With a greater understanding of these issues, we can hopefully reduce the burden caused by depression.


Chad D. Rethorst, Ph.D.
Associate Professor
Center for Depression Research and Clinical Care
Department of Psychiatry
University of Texas Southwestern Medical Center


Increased instances of arthritic knees maybe not due to just “wear and tear”

By: Lynn Millar, PT, PhD, FACSM

We certainly know that knee pain is not a new phenomenon, but are people today living lifestyles that make it more common?

Recently a study was published suggesting that the incidence of arthritis has doubled since before the 1950s. In follow-up, another researcher examined bones from museums and medical schools, and the findings also suggested an increase.

While these stats may appear shocking, I think it is important to point out a few important factors:

  • The population has expanded tremendously since prior to the 1950s
  • The average age has increased
  • Obesity has become a national epidemic

The researchers said that even when correcting for body mass and age, there was still a large increase. This led the researchers to consider lifestyle factors.

I have several thoughts related to this: Could it be that some of the changes are simply diagnosis – perhaps fewer individuals went to the doctor for knee pain prior to 1950, as they did not think there was anything abnormal about an increase in joint pain with aging? Knee replacement was not the go-to option in the early part of the 1900s, and medication options (and pain tolerance levels) have changed significantly since then. My grandmother told me knee and hip pain was a part of life!

I agree with Drs. Richard Loeser and Lieberman that lack of activity may be a culprit of increased instances of arthritis. There has been a shift away from active careers toward sedentary desk jobs.

Our bodies were not made to sit all of the time. 

As research has demonstrated time after time, exercise reduces arthritis pain and decreases the inflammation associated with arthritis. This seems to reinforce the need for motion and activity across the lifespan. It is true that injury is very predictive of the development of arthritis. However, I believe the benefits of regular exercise far outweigh the risk. One of the first components of therapy for someone with arthritis is exercise – a focus on strengthening muscles around the joint and increasing activity.

Thus, I suggest that the focus should be on getting up and moving!

Lynn Millar has taught in Physical Therapy since 1987. Lynn has been active conducting and supervising research in diverse areas of physical therapy. While specialized in Exercise Physiology, she has expanded her expertise into Cardiopulmonary Rehabilitation and arthritis throughout the years. She has published numerous articles and presented regularly at the state, regional and national level. In addition to research articles, Lynn has authored several chapters related to arthritis, and one book, Action Plan for Arthritis. Lynn has been active in the American College of Sports Medicine, serving on regional and national committees.

Active Voice: Staying Independent in Later Life – The Role of Midlife Physical Activity

By Barbara Sternfeld, Ph.D., FACSM 

More than three decades ago, James Fries published a seminal paper in the New England Journal of Medicine that predicted an expansion of the years of healthy, active life as a result of a delay in the onset of chronic disease and disability that would be greater than increases in overall life expectancy. He labeled this demographic shift the compression of morbidity. To those of us following in the steps of Drs. Jeremy Morris and Ralph Paffenbarger, Jr. in the then-emerging field of physical activity epidemiology, the compression of morbidity was a compelling hypothesis. Accumulating evidence for the role of physical activity in protecting against the major causes of morbidity and disability, such as coronary heart disease, hypertension, diabetes and some cancers, suggested that the lifetime burden of illness in the population could, indeed, be shortened by widespread adoption of regular physical activity.

Since then, much demographic analysis and debate has focused on trends in morbidity and mortality and whether there is evidence for compression of morbidity. In 2011, Crimmins and Beltran-Sanchez examined age-specific disease prevalence and mobility-related functional status from 1998 to 2006. They based their analyses on data from the National Health Interview Survey, along with age-specific mortality rates from official U.S. life tables for the same years. The data showed a slight increase in overall life expectancy over this interval, but also a decrease in life expectancy free of disease or functional impairment. This result was due, perhaps in large part, to the increase in obesity in recent years. Those authors concluded that there had been an expansion, rather than a compression, of morbidity. Despite other analyses, with evidence supporting the compression of morbidity, Crimmins and Beltrans-Sanchez argued that this finding is largely because others have focused on severe disability, such as inability to perform activities of daily living, rather than functional impairment, such as ability to walk across the street before a traffic signal changes. Medical advances, they argued, have made chronic diseases both less lethal and less disabling, yet those conditions continue to impact higher-level functioning, often at younger ages. 

Our study, published in MSSE, has direct relevance for this discussion. Using 14 years of data from SWAN (Study of Women’s Health Across the Nation), a population-based, multi-racial/ethnic cohort of midlife women, we showed that a healthy lifestyle score, consisting of regular physical activity, a healthy diet and abstention from tobacco, measured over as many as nine years during midlife, was positively associated with better physical performance, measured at least four years later in older midlife. The domains of physical performance that were associated with a healthy lifestyle were walking speed and repeated chair stands (a measure of lower body strength and endurance). Most striking, these associations were due entirely to physical activity. Although a healthy diet and abstention from smoking clearly have obvious health benefits, regular physical activity in midlife appears to be the key determinant of better mobility-related physical function in late midlife, at least for women.

These findings strongly imply that physical activity can contribute to the expansion of life expectancy without functional impairment and, effectively, bring about the achievement of the compression of morbidity that Fries envisioned several decades ago. The challenge, of course, remains the relatively modest proportion of the population that regularly engages in physical activity. Although ACSM has been a leader in the efforts to promote physical activity, much more work in this area is still needed — particularly now, at a time when public health resources are expected to be stretched even further than they have been. It is imperative that we in ACSM do what we can to ensure that all segments of the population lead healthier, active lives.

Barbara Sternfeld, Ph.D., FACSM, is an emeritus research scientist at the Kaiser Permanente Northern California Division of Research in Oakland, California, where she began her career in 1985. Dr. Sternfeld’s training is in epidemiology and exercise science. She has extensive experience with large, prospective cohort studies, most notably, the CARDIA study (Coronary Artery Risk Development in Young Adults), and SWAN (Study of Women’s Health Across the Nation). Her research interests, largely focused on women’s health issues, include longitudinal analyses of physical activity and health outcomes, methods for assessment of physical activity and intervention trials. 

This commentary presents Dr. Sternfeld’s views on the topic of a research article that she and her colleagues authored. That article appeared in the February 2017 issue of Medicine & Science in Sports & Exercise® (MSSE)

Viewpoints presented on the ACSM blog reflect opinions of the authors and do not necessarily reflect positions or policies of ACSM. 

The Science of Exercise

By Jordan Metzl, M.D. 

In today’s news, much of the information we read about exercise is driven by the latest craze or fad in fitness and weight loss. These often confusing circumstances can be frustrating for individuals looking to make true lifestyle changes that improve their health. As a physician, I have witnessed many clients struggle to sort through the “noise,” so I was honored when approached to write the introduction for a special edition of TIME Magazine titled “The Science of Exercise.” TIME engaged a variety of subject matter experts to bring its readers science-backed fitness and exercise information that will help them make informed choices about their physical activity. As a nod to ACSM’s position as the global authority in this space, several of my ACSM colleagues also contributed to this issue, including Jack Berryman, FACSM, Steven Blair, 40th President of the American College of Sports Medicine (1996-97), Anthony Hackney, FACSM, and Pamela Peeke, FACSM. The issue also references ACSM’s exercise recommendations and cites ACSM’s journal Medicine & Science in Sports & Exercise

I have seen numerous patients meet and exceed their health goals through exercise, and I am a true supporter of Exercise Is Medicine®, a global health initiative managed by ACSM. The benefits of physical activity on health have been proven time and time again, both in the research lab and the gym. I’d encourage each of you to pick up an issue of this outstanding TIME Magazine publication about exercise, the miracle drug. Here’s a preview of my article:

Thankfully, you don’t need to take mega-doses of this drug [exercise] to get the benefits. A little bit goes a long way. 

The American College of Sports Medicine recommends 150 minutes of exercise per week— just about 30 minutes, five days a week. More is better, but this seems to be the sweet spot. Anything from brisk walking to jogging to hightailing it up the stairs counts. And the harder you’re willing to push yourself, the less time you’ll have to commit to enduring it. 

If I had my way, medicine’s four core vital signs — temperature, pulse, blood pressure and respiration rate — would be joined by a fifth: step count, with a goal of 10,000 per day. It should be part of every standard medical chart, right alongside height and weight.

Don’t forget that May is Exercise is Medicine Month- download the toolkit today and help make a difference in your community. I hope to see you all in Denver at the ACSM Annual Meeting, where I will be presenting on a physician-led fitness community called the IronStrength Community Fitness Program that I lead in New York.

Viewpoints presented on the ACSM blog reflect opinions of the authors and do not necessarily reflect positions or policies of ACSM. 

Jordan Metzl, M.D., is a 19-year member of ACSM and a sports medicine physician at the Hospital for Special Surgery in New York City. He is pioneering a bridge between the medical and fitness communities by leading the first physician-led fitness program that he calls the IronStrength Community program. 

In addition to his medical practices in New York City and Stamford, Connecticut, Dr. Metzl is the author of six books, including the bestselling titles Running Strong, The Exercise Cure and Athlete’s Book of Home Remedies. Dr. Metzl is also the medical columnist for Triathlete Magazine.