Regular exercise is associated with numerous physical and mental health benefits in men and women. All because death is delayed by routinely engaging in physical activity. This is also the case when an individual changes from a sedentary lifestyle to recommended fitness standards.

What are the health benefits of exercise?

Exercise prolongs life by decreasing the risk of developing one or more of the major causes of death: coronary heart disease, stroke, type 2 diabetes, and some forms of cancer (for example, colon and breast cancers). This is achieved by:

• lowering the blood pressure

• improving lipids [cholesterol and triglycerides]

• decreasing inflammation and oxidation markers linked to coronary disease, stroke and cancer

• enhancing insulin sensitivity [ie, its impact on tissue to decrease sugar level and prevent diabetes]

• keeping weight down.

In addition, and of particular relevance to older adults, exercise preserves bone mass and reduces the risk of falling.

Also, improvement in mild to moderate depressive disorders and anxiety can occur with exercise. In fact, a physically active lifestyle enhances feelings of energy, wellbeing and quality of life as assessed by multiple clinical scores, and cognitive function (lower risk of dementia).

What are the components of physical fitness?

They are three:

• cardiorespiratory fitness: heart and lung wellbeing

• musculoskeletal fitness, which includes muscle strength and endurance, joint flexibility and bone density. Combined, they make up one’s “body composition”

• neuropsychiatric fitness: brain age, mood status and cognitive integrity.

How much should I exercise?

The minimum level of physical fitness required for health benefit may be different for older and younger adults.

This is because of the non-linear, or rather steep fitness decline that occurs with advancing age when not accompanied by a programme of regular exercise. Younger people, on the other hand, even when not active, tend to have a slower drop.

As a general rule, adults should try to be active on a daily basis, and aim to achieve at least 150 minutes of exercise over a week through a variety of activities.

How much is too much?

A 2015 study that received wide media coverage showed that while the risk of cardiac death is well reduced in patients who pursue a mild and moderate amount of jogging, it is the same in people who pursue vigorous running as in those who are sedentary. Other studies do not support this conclusion.

What are the risks associated with exercise and how can they be reduced?

• Musculoskeletal risks: Injury is the most common exercise-related complication. The type and intensity of the exercise seems to be more important factors in the incidence of injury than the amount of exercise performed.

Walking, jogging and other moderate-intensity physical activities are associated with a very low risk of physical injury, whereas running and competitive sports are associated with an increase in such risk.

Unaccustomed exercise demands, especially during the initial weeks of a physical conditioning regimen, often result in muscle soreness and attrition.

Rhabdomyolysis is an uncommon but serious disorder resulting from significant damage to the skeletal muscle that can cause kidney failure, cardiac arrhythmias and, in rare cases, death.

Its risk is increased in both experienced and novice exercisers who undertake unaccustomed, eccentric exercise, particularly under hot, ambient conditions.

Commonly used methods to reduce musculoskeletal injury and complications, such as “warm-up” and “cool down”, stretching, and gradual progression of volume and intensity of exercise, seem to be helpful, but rigorous studies substantiating their effectiveness are insufficient.

• Cardiac risks: Sudden death can be triggered by unaccustomed vigorous physical exertion, particularly in sedentary people with yet undiagnosed or known coronary disease. Population studies have shown that forewarning signs or symptoms often precede exercise-related cardiac events, but individuals and their healthcare providers may ignore or inadequately evaluate these, especially in habitually active persons.

Using a well-designed medical history questionnaire (such as the physical activity readiness questionnaire) to identify conditions, signs, symptoms, and risk factors that are associated with an increased risk of cardiac events during and after exercise may be useful and effective.

While widely used, fewer data support the role of routine diagnostic stress-testing as an effective method for reducing the risk of exercise-related cardiac events.

There are no exact studies demonstrating the effectiveness of supervision by a well-trained fitness professional in reducing the risks of exercise, but the low rate of exercise-related complications in medically supervised exercise programmes supports the likelihood of benefit, particularly for novice exercisers.

Patients with some unusual conditions, mainly myocarditis, left or right cardiomyopathies, and those who are born with particular coronary anomalies should be restricted from exercising.

In a small group of patients, vigorous exercise can precipitate atrial fibrillation and, very rarely, other rhythm problems.

• Joe Yammine is a cardiologist at Bermuda Hospitals Board. He trained at the State University of New York, Brown University and Brigham and Women’s Hospital. He holds five American Board certifications. He was in academic practice between 2007 and 2014, when he joined BHB. During his career in the US, he was awarded multiple teaching and patients’ care recognition awards. The information herein is not intended as medical advice nor as a substitute for professional medical opinion. Always seek the advice of your physician. You should never delay seeking medical advice, disregard medical advice or discontinue treatment because of any information in this article