Physical inactivity and lack of sleep are independently associated with an increased risk of death and / or cardiovascular disease and cancer. But these two lifestyle factors are closely related and act synergistically, both positively and negatively as a study conducted by Australian researchers and published reveals. in the British Journal of Sports Medicine. This examines the joint effects of these two behaviors and reveals that people who have both poor quality of sleep and who practice the least physical exercise sare most at risk of dying from heart disease, stroke and cancer.
To come to this conclusion, the researchers relied on 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 minutes of metabolic equivalent (MET for metabolic equivalent of task), defined as the ratio of energy expenditure linked to physical activity over basal metabolism. For example, 600 MET minutes per week equals 150 minutes of moderate-intensity activity or more than 75 minutes of vigorous-intensity physical activity per week. The minimum recommended practice by WHO.
Sport, diet … the key to good sleep
In parallel, the quality and duration of sleep were categorized using a sleep score of 0 to 5, and this information provided researchers with a dozen different physical activity / sleep pattern combinations. The health of the participants was monitored 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 4,095 from cardiovascular disease and 9,064 from cancer.
For the remaining participants, 59% of them were members of the “high physical activity” group, 15% of the “moderate physical activity” group, 10% of the “weak” group, and 16% of the “without moderate to vigorous physical activity” group. »More than half (56%) of participants had a healthy sleep pattern, 42% had moderate quality sleep, and 3% were poor sleepers. The researchers were able to establish the profile of the people with the best sleep score: generally female, with a good healthy weight, regular consumers fruits and vegetables, not very sedentary, who did not smoke and drink little alcohol, and among the most physically active.
Physical activity, the pillar of good health
The results showed that more the sleep score is low, the greater the risk of death from all causes, all types of cardiovascular disease and stroke. It turns out that people who had the worst combination of physical activity / sleep had a higher risk of death from all causes of around 57% compared to people who had the best possible combination: 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 of the lung (91% higher).
Above all, the researchers noted the importance physical activity for health because low levels of practice amplified the unfavorable associations between poor sleep and the risk of mortality from all causes except stroke. “Physical activity levels at or above WHO guidelines (600 MET-minutes per week) have eliminated most of the deleterious associations between poor sleep and mortality. These results lend weight to efforts to target both physical activity and quality of sleep with the aim of improving health. », They conclude. Note that according to the WHO, between four and five million deaths could be avoided each year if the world’s population were more physically active.