Physical activity

What is it?

According to WHO: physical activity is any bodily movement produced by skeletal muscles that requires energy expenditure, and includes recreation, transport, work and household activities.

MedlinePlus identifies four types of exercise: aerobic (walking, running, swimming), strength and resistance exercises (weights, bands or body weight), balance exercises (such as tai chi), and flexibility exercises (stretching and yoga).

Why it matters

For children and adolescents: it improves fitness, cardiometabolic health, bone health, cognitive outcomes and mental health, and reduces body fat (WHO).

For adults and older adults: it reduces the risk of death from any cause, cardiovascular death, the onset of hypertension, some cancers, type 2 diabetes and falls, and improves mental health, cognitive function and sleep (WHO).

The CDC lists benefits that include: maintaining weight, lowering the risk of heart disease and stroke, lowering blood pressure and improving cholesterol, lowering the risk of type 2 diabetes and metabolic syndrome, lowering the risk of at least eight types of cancer, protecting joints and muscles, reducing falls in older adults, easing arthritis pain, and reducing short-term anxiety in adults.

WHO states that people who are not sufficiently active have a 20% to 30% higher risk of death than those who are sufficiently active, and that sedentary behaviour is associated with increased deaths, heart disease, cancer and type 2 diabetes.

Key points

According to WHO: 31% of adults and 80% of adolescents do not reach the recommended levels, and women are less active than men by an average of 5 percentage points.

The CDC says that benefits begin even with less than 150 minutes a week as regards type 2 diabetes and metabolic syndrome, and that 150 minutes a week of moderate activity helps maintain weight, whereas losing weight requires dietary change alongside it.

The CDC states that adults under 60 are advised about 8,000 to 10,000 steps a day, and those over 60 about 6,000 to 8,000 steps (as stated on the page).

How to put it into practice

Adults (18 to 64 years): according to the CDC, at least 150 minutes a week of moderate-intensity activity such as brisk walking, with at least 2 days a week of muscle-strengthening activities.

Children aged 3 to 5: physical activity every day and throughout the day through active play (CDC). Children and adolescents (6 to 17): 60 minutes or more a day of moderate to vigorous activity, with vigorous, muscle-strengthening and bone-strengthening activities (such as running, rope climbing and skipping) on at least three days a week (CDC).

Older adults (65 and over): 150 minutes or more a week of moderate activity such as brisk walking, with at least 2 days of muscle strengthening, and activities to improve balance (CDC).

People with chronic conditions and disability: the CDC states at least 150 minutes (for example 30 minutes on five days) a week of moderate aerobic activity with at least 2 days of strengthening for the major muscles, and MedlinePlus advises consulting a care provider before starting, especially if there are mobility or balance problems.

Special groups

Pregnancy and after childbirth: the CDC states at least 150 minutes (for example 30 minutes on five days) a week of moderate aerobic activity such as brisk walking during pregnancy and after childbirth.

According to WHO, activity may reduce the risk of pre-eclampsia, gestational hypertension, gestational diabetes, excessive gestational weight gain, birth complications, postnatal depression and newborn complications. Each pregnant woman's plan remains for her doctor to decide.

The WHO page does not give the minutes for each group here, and WHO stresses that its guidelines cover children, adolescents, adults, older adults, pregnant and postpartum women, and people with chronic conditions or disability.

Risks and cautions

MedlinePlus advises stopping exercise and getting help immediately if you feel pain, severe shortness of breath or dizziness.

It also advises consulting a health care provider before starting, especially for people with mobility or balance problems.

Limits of this information

WHO's fact page does not give durations as numbers, so the CDC figures for the groups were used, and these are US guidelines. Needs vary from person to person, and what applies to you is what your doctor or dietitian decides according to your situation.

The link between inactivity and diseases such as diabetes and cancer on the WHO page is a statistical association and does not mean that activity alone prevents or treats the disease.

Common questions