Physical activity levels at or above the weekly amounts recommended by the World Health Organization (WHO) can counteract the serious health problems associated with poor sleep quality, suggests a major study that demonstrates the importance of both factors for optimal health.

High, levels, of, physical, activity, can, counteract, the, effects, poor, sleep

Physical inactivity and sleep deprivation are independently associated with an increased risk of death and/or cardiovascular disease and cancer. But these two lifestyle factors are closely linked and act synergistically, both positively and negatively, as revealed by a study conducted by Australian researchers and published in the British Journal of Sports Medicine. The study looked at the joint effects of these two behaviors and found that people who had both poor sleep quality and the least amount of exercise were at the highest risk of dying from heart disease, stroke and cancer.

To reach this conclusion, researchers used information provided by 380,055 middle-aged men and women participating in the UK Biobank study. Participants provided information on their weekly physical activity levels, measured in metabolic equivalent of task (MET) minutes, defined as the ratio of energy expenditure from physical activity to basal metabolic rate. For example, 600 MET minutes per week is equivalent to 150 minutes of moderate-intensity activity or more than 75 minutes of vigorous-intensity physical activity per week. This is the minimum amount of physical activity recommended by the WHO.

Sport, diet... the key to good sleep

In parallel, sleep quality and duration were categorized using a sleep score from 0 to 5, and this information provided allowed the researchers to obtain a dozen different physical activity/sleep rhythm combinations. Participants' health was tracked for an average of 11 years until May 2020 or until the person died. The goal: to assess their risk of dying from any cause, including cardiovascular or coronary heart disease, heart attack or cancer. During the follow-up period, 15,503 people died, including 4095 from cardiovascular disease and 9064 from cancer.

For the remaining participants, 59% were members of the "high physical activity" group, 15% of the "moderate physical activity" group, 10% of the "low" group, and 16% of the "no moderate to vigorous physical activity" group. "More than half (56%) of the participants had a healthy sleep pattern, 42% had intermediate quality sleep, and 3% were poor sleepers. The researchers were able to profile the people with the best sleep scores: generally female, with a good body weight, regular consumers of fruits and vegetables, not very sedentary, who did not smoke and drank little alcohol and among the most physically active.

Physical activity, the pillar of good health

The results showed that the lower the sleep score, the higher the risk of death from all causes, all types of cardiovascular disease and stroke. It turns out that people with the worst combination of physical activity and sleep had a 57% higher risk of death from all causes compared to people with the best possible combination of high physical activity and healthy sleep score. They also had a higher risk of death from any type of cardiovascular disease (67% higher) and from any type of cancer (45% higher), especially lung (91% higher).

Most importantly, the researchers found the importance of physical activity for health because low levels of practice amplified the adverse associations between poor sleep and risk of all-cause mortality apart from stroke. "Physical activity levels at or above WHO guidelines (600 MET-minutes per week) eliminated most of the deleterious associations between poor sleep and mortality. These results lend weight to efforts to target both physical activity and sleep quality for improved health. "They conclude. Note that according to the WHO, between four and five million deaths could be prevented each year if the world's population was more physically active.