We need to better understand the effects of exercise on sleep
We know that not getting enough good sleep is bad for us and science confirms this. Insufficient and poor-quality sleep increases risk for high blood pressure, elevated cholesterol, atherosclerosis, weight gain, diabetes, and cardiovascular disease. Exercise is often recommended to help with sleep. But exercise is a broad term.
“It is increasingly recognized that getting enough sleep, particularly high-quality sleep, is important for health including cardiovascular health. Unfortunately, more than a third of Americans don’t get enough sleep on a regular basis. Aerobic activity is often recommended to improve sleep, yet very little is known about the effects of resistance exercise versus aerobic exercise on sleep. Our study is one of the largest and longest exercise trials in a general adult population to directly compare the effects of different types of exercise on multiple sleep parameters,” said study author Angelique Brellenthin, Ph.D., assistant professor at Iowa State University.
Cycling, weight lifting, or both?
To understand the effects of resistance and aerobic exercise, researchers included 386 adults. They selected those who were overweight, inactive, and had elevated blood pressure. For 12 months, they were divided into four groups based on the type of exercise. They participated in supervised 60-minute sessions 3x per week.
- Aerobic group – Participants could choose between treadmill, bikes or ellipticals. Researchers monitored their heart rates to keep them continuously in the prescribed heart rate range for a moderate-to-vigorous intensity exercise.
- Resistance group – Participants used 12 resistance machines to work all the major muscle groups in every session. They were instructed to perform 3 sets of 8 to 16 repetitions at 50-80% of their one-rep maximum.
- Combination group – The combination group did 30 minutes of aerobic exercise and 30 minutes of resistance exercise.
- Control group – Participants did no exercise.
The study participants were assessed at the start and then at the 12-month mark. On top of that, they were self-reporting on sleep duration and quality during the whole experiment.
Resistance exercise helps poor sleepers the most
The most significant results were observed among the participants who were not getting at least 7 hours of sleep at the study’s start which was 42% of total participants.
- Aerobic group – sleep duration increased by an average of 23 minutes
- Resistance group – sleep duration increased by an average of 40 minutes
- Combination group – sleep duration increased by an average of 17 minutes
- Control group – sleep duration increased by an average of 15 minutes
The researchers also noted that sleep efficiency increased in the resistance exercise and combined exercise groups, but not in the aerobic exercise or control group. Sleep efficiency describes how much time one is actually asleep out of the total amount of time spent in bed. The resistance group was also the only one to improve the time it took participants to fall asleep. They improved by 3 minutes.
“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. Resistance exercise significantly improved sleep duration and sleep efficiency, which are critical indicators of sleep quality that reflects how well a person falls asleep and stays asleep throughout the night. Therefore, 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,” concluded Brellenthin.