After I wrote last year that diet, not exercise, was the key to weight loss, I was troubled by how some readers took this to mean that exercise therefore had no value. Nothing could be further from the truth. Of all the things we as physicians can recommend for health, few provide as much benefit as physical activity.
In 2015, the Academy of Medical Royal Colleges put out a report calling exercise a “miracle cure.” This isn’t a conclusion based simply on some cohort or case-control studies. There are many, many randomized controlled trials. A huge meta-analysis examined the effect of exercise therapy on outcomes in people with chronic diseases.
Let’s start with musculoskeletal diseases.
Researchers found 32
trials looking specifically at the effect of exercise on pain and function of patients with osteoarthritis of the knee alone. That’s incredibly specific, and it’s impressive that so much research has focused on one topic.
Exercise improved those outcomes. Ten more studies showed, over all, that exercise therapy increases aerobic capacity and muscle strength in patients with rheumatoid arthritis. Other studies proved its benefits in other musculoskeletal conditions, like ankylosing spondylitis, and even some types of back pain.
For people (mostly middle-aged men) who had had a heart attack, exercise therapy reduced all causes of mortality by 27 percent and cardiac mortality by 31 percent. Fourteen additional controlled trials showed physiological benefits in those with heart failure. Exercise has also been shown to lower blood pressure in patients with hypertension, and improve cholesterol and triglyceride levels.
People with diabetes who exercise have lower HbA1c values, which is the marker of blood sugar control, low enough to probably reduce the risk of complications from the disease. Twenty randomized controlled trials have showed that patients with chronic obstructive pulmonary disease can walk farther and function better if they exercise.
Multiple studies have found that exercise improves physical function and health-related quality of life in people who have Parkinson’s disease. Six more studies showed that exercise improves muscle power and mobility-related activities in people with multiple sclerosis. It also appeared to improve those patients’ moods.
The overall results of 23 randomized controlled trials showed that exercise most likely improves the symptoms of depression. Five others appear to show that it improves symptoms in patients with chronic fatigue syndrome. In trials, exercise even lessened fatigue in patients who were having therapy for cancer.
What other intervention can claim results like these?
Even studies of older, hospitalized patients show a beneficial effect from multidisciplinary interventions that include exercise. Those randomized to such interventions in the hospital were more likely to be discharged to go home, and to spend less time in the hospital over all — and at a lower cost.