Prescribing lifestyle changes can be challenging; patients often adhere to such changes sporadically and may have trouble sustaining them in the long term. Many clinicians assume that in order to change the trajectory of health for a patient, healthy exercising habits must be consistent. However, some exciting new research has emerged suggesting that the physical benefits of exercise may persist even if a patient reduces or stops exercising.1
In a randomized control study, 384 sedentary, overweight individuals aged 40–60 participated in one of four exercise groups differing in intensity and amount for eight months.2 Participants were randomized into one of four groups: low amount/moderate intensity exercise, low amount/vigorous intensity exercise, high amount/vigorous intensity exercise, or inactive controls.2 Scientists tracked their aerobic fitness, blood pressure, insulin sensitivity, and waist circumference. Not surprisingly, during the original study, each of these health markers improved in the three groups who exercised and not in the controls.2
To determine if there were legacy effects from this intervention, 104 participants (52 men and 52 women) returned for a reunion study.1 After more than a decade, there were reductions in both time-to-exhaustion and peak VO2 for all exercise groups, but in the two vigorous intensity training groups, the fitness reductions were about half as much.1 Additionally, all three exercise training groups benefitted from both a decrease in waist circumference during training and a much slower increase in waist circumference over the following 10 years. Most of the participants from the control group who had not exercised 10 years before had larger waistlines and were less physically fit.1
What was responsible for this effect? Did the participants in the exercise programs continue their increased activity over the following years? While some participants kept up with their exercise at a reduced intensity following the study and some did not, all participants in the exercise groups showed some improvement, even the ones who stopped exercising, although recent exercise did explain some of the variance in the health measures.
“Compared to those without a defined exercise training exposure, vigorous exercise training offers benefits for maintaining aerobic fitness; moderate intensity exercise training produces sustained legacy effects on metabolic parameters; and any exercise training helps maintain body weight and waist circumferences better than continued inactivity,” writes Johanna Johnson et al in Frontiers of Physiology.1 “The importance of these findings is hard to overestimate from both individual and global health viewpoints. If a single, prolonged 8-month exercise training study can lead to behavior changes that continue for 10 years—with the attendant health benefits—this would have potentially sizeable and widespread beneficial effects.”1
But the news coming from recent research isn’t all good. Just prior to the publication of this study came a smaller, but somewhat concerning new study suggesting that sitting for more than 13 hours a day may sabotage the metabolic benefits of exercise.3 In the study, scientists at the University of Texas at Austin asked a group of 10 healthy, physically active graduate students if they would remain still for at least 13 hours a day and take fewer than 4,000 steps—four days in a row. Then, four days of prolonged sitting without exercise were compared with four days of prolonged sitting with a one-hour bout of treadmill exercise. What the researchers found was that in people who are physically inactive and sitting for the majority of the day, a one-hour bout of vigorous exercise did not improve lipid, glucose, and insulin metabolism measured the next day.3
These results suggest that being sedentary for long periods of time may create conditions inside our bodies “that make us resistant to the usual metabolic improvements after acute exercise,” Dr. Edward Coyle, a professor of kinesiology at UT-Austin and senior author of the new study, told The New York Times.4
Like many things in life, exercise does not have to be “all or nothing.” Even slight modifications in exercise intensity over the course of a lifetime can have lasting effects on health—standing instead of sitting, bursts of aerobic activity followed by periods of inactivity—all of these small changes in behavior will leave your patients healthier than if they never exercised to begin with. That’s something positive to remember if patients feel defeated about maintaining their exercise regimen.
Can exercise also protect the brain? LEARN MORE
- Johnson JJ, Slentz CA, Ross LM, Huffman KM, Kraus WE. Ten-year legacy effects of three eight-month exercise training programs on cardiometabolic health parameters. Front Physiol. 2019;10:452. doi:10.3389/fphys.2019.00452
- Kraus WE, Torgan CE, Duscha BD, et al. Studies of a targeted risk reduction intervention through defined exercise (STRRIDE). Med Sci Sports Exerc. 2001;33(10):1774-1784.
- Akins JD, Crawford CK, Burton HM, Wolfe AS, Vardarli E, Coyle EF. Inactivity induces resistance to the metabolic benefits following acute exercise. J Appl Physiol. 2019;126(4):1088-1094. doi:10.1152/japplphysiol.00968.2018
- Reynolds G. Sitting for more than 13 hours a day may sabotage the benefits of exercise. The New York Times. Published April 10, 2019. Accessed May 30, 2019. https://www.nytimes.com/2019/04/10/well/move/sitting-for-more-than-13-hours-a-day-may-sabotage-the-benefits-of-exercise.html