Exercise counters negative effects of unhealthy sleep habits, study suggests

Exercise can counter some of the negative effects of sleeping too little or very long, according to a new study that assessed over 90,000 adults.

While previous studies have revealed that both sufficient exercise and healthy sleep can prolong life expectancy, it has remained unclear how physical activity interacts with sleep duration to promote health, said researchers, including those from Guangzhou Medical University in China.

The new research, published recently in the European Journal of Preventive Cardiology, examined the joint effects in 92,221 adults between 40 and 73 years of age in the UK who wore an accelerometer wristband for one week in 2013-15.

Scientists classified sleep duration per night as short (less than six hours), normal (six to eight hours), or long (more than eight hours), and divided physical activity data into either low, intermediate or high.

During a median follow up of seven years, 3,080 participants died – 1,074 from cardiovascular disease and 1,871 from cancer.

In those with low amounts of exercise, short sleep was linked to 16 per cent and long durations of sleep was associated with 37 per cent raised risks of all-cause death.

Scientists noted a 41 per cent raised likelihood of all-cause death in participants with intermediate amounts of exercise and too little sleep.

They also found sleep duration was not linked with risk of death in those with a high amount of exercise.

Short sleepers with a low volume of exercise had a 69 per cent elevated risk of death from heart disease, which disappeared when exercise increased to moderate or high volumes, scientists said.

“Our findings suggest that health promotion efforts targeting both physical activity and sleep duration may be more effective in preventing or delaying premature death in middle-aged and older adults than focusing on one behavior alone,” said study co-author Jihui Zhang from the Guangzhou Medical University.

“In an ideal scenario, people would always get healthy amounts of both sleep and physical activity. However, our study indicates that getting sufficient exercise may partially offset the detrimental impact of missing a good night’s sleep,” Dr Zhang said.