Pumping iron is a sleep aid – and a heart help

Middle aged woman lifting weights 
(Bill Oxford/E+, Getty Images)

Resistance training, such as lifting weights, beats out aerobic exercise in improving the duration and quality of sleep, according to new preliminary research. And better sleep means better heart health by reducing the risk for high blood pressure, elevated cholesterol and atherosclerosis.

"It is increasingly recognized that getting enough sleep, particularly high-quality sleep, is important for health, including cardiovascular health," study author Angelique Brellenthin said in a news release. Brellenthin is an assistant professor of kinesiology at Iowa State University in Ames. 

Insufficient sleep has been linked to weight gain, diabetes and inflammation, which are heart-related risk factors. Too much or not enough sleep has been shown to raise the risk for heart disease and stroke.

The study compared the effects of different kinds of exercise on sleep outcomes.

"While both aerobic and resistance exercise are important for overall health, our results suggest that resistance exercises may be superior when it comes to getting better ZZZs at night," Brellenthin said.

Researchers randomly assigned 386 inactive, overweight adults with high blood pressure to one of several groups: supervised resistance or aerobic exercise three times a week for 60 minutes over a year; combined resistance/aerobic exercise; or a control group with no supervised exercise.

Resistance exercise participants worked all major muscle groups using 12 resistance machines to do three sets of eight to 16 repetitions on each machine. Aerobic exercise participants could choose among treadmills, upright or recumbent bicycles, or elliptical machines, which they used with moderate to vigorous intensity to get their heart rate into the target range. The combination group split their time between the types of exercise during each session.

Total sleep quality, sleep duration, the time it took to fall asleep, the time they spent in bed and the number and frequency of sleep disturbances were measured using self-reported questionnaires at the beginning of the study and again at the end of one year.

Overall, the quality of sleep improved, and the number of sleep disturbances decreased, for all groups in the study. Among the 42% of participants who began the study getting less than seven hours of sleep a night, those doing resistance exercise – but none of the other groups – were able to extend their average sleep time by 17 minutes per night. Those doing resistance exercise also found it took three minutes less to fall asleep each night.

"If your sleep has gotten noticeably worse over the past two stressful years, consider incorporating two or more resistance exercise training sessions into your regular exercise routine to improve your general muscle and bone health, as well as your sleep, recommends Brellenthin."

The results are considered preliminary until the full findings are published in a peer-reviewed journal.