The Evidence: The Wonderful Effects of Exercise

What current exercise research shows

Melissa Morales, MD MPH

1/12/20244 min read

person wearing orange and gray Nike shoes walking on gray concrete stairs
person wearing orange and gray Nike shoes walking on gray concrete stairs

It's 1990. My mom's Jane Fonda exercise video tape is in the VCR. I'm jumping along with Jane Fonda, enjoying the movement of my body and feeling the invigoration of exercise. As a not too particularly athletic kid, living in a hot climate, indoor exercise like this gave me an opportunity to learn more about my body's capabilities and of course, helped me to expend extra energy. We have all been told that exercise is good for us, but how exactly is it good for us, and what affect does it have on those of us who want to lose a few extra pounds?

There is no doubt that exercise has countless health benefits. Regular aerobic exercise has been known to reduce mortality rates (1,2,3) and heart disease (4,5). It can also reduce inflammation in the body that can lead to heart disease (6). It also reduces the risk of stroke (7). Both aerobic and strength training can improve metabolic health and help improve diabetes (8). Strength training helps to develop the muscles that support joints, which can improve symptoms of arthritis. In multiple studies, exercise has improved sleep, stress and has reduced the risk for depression (9,10,11).

What about weight loss? Well, lets start with whether or not it prevents weight gain. In one study, a group of healthy 20 somethings who were normal weight were followed for 20 years into middle age. Those who did about 150 minutes of moderate intensity exercise per week were able to prevent weight gain (12). So, for those of you in college or in your 20's who are normal weight, regular exercise determines whether or not you will continue to maintain a normal weight into your 30's and 40's. If you are overweight, it may be impossible to maintain your weight with exercise alone (13).

So what about if you are overweight and need to lose weight? Again exercise alone will only modestly reduce weight (14). This may be because when we maintain an exercise routine, there is an increase in muscle mass and blood plasma volume. Also, in practice, it may be difficult to maintain a moderate-vigorous exercise routine for the long term. But, pounds are not the only measure of a healthier body. Although exercise alone may not result in huge drops on the scale, it does reduce body fat, including abdominal fat, waist circumference and visceral fat -the fat found around your organs (14). Exercise may also help to reduce the loss of muscle mass and bone mass during weight loss. Finally, once you have lost weight, exercise may help to maintain your weight loss (15).

So, whether you like to jog, walk, swim or aerobicize with Jane Fonda, evidence shows that exercise is an important part of your wellness and weight loss journey!


  1. Lear SA, Hu W, Rangarajan S, et al. The effect of physical activity on mortality and cardiovascular disease in 130 000 people from 17 high-income, middle-income, and low-income countries: the PURE study. Lancet 2017; 390:2643.

  2. Andersen LB, Schnohr P, Schroll M, Hein HO. All-cause mortality associated with physical activity during leisure time, work, sports, and cycling to work. Arch Intern Med 2000; 160:1621.

  3. Paffenbarger RS Jr, Hyde RT, Wing AL, et al. The association of changes in physical-activity level and other lifestyle characteristics with mortality among men. N Engl J Med 1993; 328:538.

  4. Khurshid S, Al-Alusi MA, Churchill TW, et al. Accelerometer-Derived "Weekend Warrior" Physical Activity and Incident Cardiovascular Disease. JAMA 2023; 330:247.

  5. Wessel TR, Arant CB, Olson MB, et al. Relationship of physical fitness vs body mass index with coronary artery disease and cardiovascular events in women. JAMA 2004; 292:1179.

  6. Hamer M, Sabia S, Batty GD, et al. Physical activity and inflammatory markers over 10 years: follow-up in men and women from the Whitehall II cohort study. Circulation 2012; 126:928.

  7. Wendel-Vos GC, Schuit AJ, Feskens EJ, et al. Physical activity and stroke. A meta-analysis of observational data. Int J Epidemiol 2004; 33:787

  8. Colberg SR, Sigal RJ, Yardley JE, et al. Physical Activity/Exercise and Diabetes: A Position Statement of the American Diabetes Association. Diabetes Care 2016; 39:2065.

  9. Herring MP, O'Connor PJ, Dishman RK. The effect of exercise training on anxiety symptoms among patients: a systematic review. Arch Intern Med 2010; 170:321.

  10. Schuch FB, Vancampfort D, Firth J, et al. Physical Activity and Incident Depression: A Meta-Analysis of Prospective Cohort Studies. Am J Psychiatry 2018; 175:631.

  11. Gordon BR, MCDowell CP, Hallgren M et. Association of Efficacy of Resistance Exercise Training with Depressive Symptoms. JAMA Psychiatry 2018.

  12. Hankinson AL, Daviglus ML, Bouchard C, et al. Maintaining a high physical activity level over 20 years and weight gain. JAMA 2010; 304:2603.

  13. Lee IM, Djoussé L, Sesso HD, et al. Physical activity and weight gain prevention. JAMA 2010; 303:1173.

  14. McTiernan A, Sorensen B, Irwin ML, et al. Exercise effect on weight and body fat in men and women. Obesity (Silver Spring) 2007; 15:1496.

  15. Thorogood A, Mottillo S, Shimony A, et al. Isolated aerobic exercise and weight loss: a systematic review and meta-analysis of randomized controlled trials. Am J Med 2011; 124:747.

  16. Avenell A, Brown TJ, McGee MA, et al. What interventions should we add to weight reducing diets in adults with obesity? A systematic review of randomized controlled trials of adding drug therapy, exercise, behaviour therapy or combinations of these interventions. J Hum Nutr Diet 2004; 17:293.


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