Physical activity may counter serious harms of poor sleep

The study, which was published online in the British Journal of Sports Medicine outlined that adults who included at least 2.5 hours of moderate-intensity exercise per week, or at least 1.75 hours of vigorous exercise per week, could improve the risks of cardiovascular disease and cancer.

More lifestyle:

Those who had both the poorest sleep quality and who exercised the least were most at risk of death from heart disease, stroke, and cancer, according to PhD candidate Bo-Huei Huang, and lead author of the study.

"Both behaviours are critical for health, but, sadly, our society suffers from both a physical inactivity and a poor sleep crisis," said the study's senior author, Professor Emmanuel Stamatakis from the Charles Perkins Centre and the Faculty of Medicine and Health at the University of Sydney.

"Considering that physical activity is perhaps more modifiable than sleep, our study offers people more health incentives to be physically active; and provides health professionals with more reasons to prescribe physical activity to patients with sleep problems."

Both physical inactivity and poor sleep are independently associated with a heightened risk of death or cardiovascular disease and cancer. But it has not been clear if they might exert a combined effect on health.

To explore this further, the researchers drew on information provided by 380,055 middle-aged (average age 55) men and women taking part in the UK Biobank study.

The UK Biobank is tracking the long-term health of more than half a million 37 to 73 year olds, who were recruited from across the UK between 2006 and 2010.

Participants supplied information on their normal weekly physical activity levels, which were measured in Metabolic Equivalent of Task (MET) minutes. These were roughly equivalent to the amount of energy (calories) expended per kilogram of body weight per minute of physical activity.

For example, 600 MET minutes a week is the equivalent of 150 minutes (2.5 hours) of moderate-intensity activity, or more than 75 minutes of vigorous-intensity physical activity a week.

Physical activity levels were categorised as high (1200 or more MET minutes/week), medium (600 to less than 1200) or low (1 to less than 600), and no moderate to vigorous physical activity, according to World Health Organization guidelines.

Sleep quality was categorised using a 0-5 sleep score derived from chronotype ('night owl' or 'morning lark' preference), sleep duration, insomnia, snoring and daytime sleepiness: healthy (4+); intermediate (2-3); or poor (0-1).

A dozen physical-activity and sleep-pattern combinations were derived from the information supplied. Participants' health was then tracked for an average of 11 years up to May 2020 or death, whichever came first, to assess their risk of dying from any cause as well as from all types of cardiovascular disease; coronary heart disease; stroke; all types of cancer; and lung cancer.

The research found, that those who were younger, female, had lower body mass index, better off financially, ate more fruit and vegetables, spent less of their day seated, had no mental health issues, never smoked, didn't work shifts, drank less alcohol and were more physically active tended to have healthier sleep scores.

The lower the sleep score, the higher were the risks of death from any cause, from all types of cardiovascular disease, and from ischaemic stroke.

Those at the other end of the scale, with the no moderate to vigorous physical activity and poor sleep combination, had the highest risks of death from any cause (57 per cent higher). They also had the highest risk of death from any type of cardiovascular disease (67 per cent higher), from any type of cancer (45 per cent higher), and from lung cancer (91per cent higher).

Lower levels of physical activity amplified the unfavourable associations between poor sleep and all health outcomes, except for stroke.