Ask the Doctors 4/5
Dear Doctors: I sometimes have trouble sleeping. I’ve tried running, which helps with stress, but not with sleep. My husband says he just heard on the news that weightlifting is supposed to be good for sleep. Do you know if this is true?
Dear Reader: We suspect your husband is referring to the preliminary results of a new study, presented earlier this year at an American Heart Association conference, that found that resistance training, such as lifting weights, can have a beneficial effect on sleep. The study’s outcomes affirm previous research, which has also found that resistance training can offer sleep benefits. Before we get to the details, we want to point out that this study hasn’t yet completed peer review. That’s the process in which other experts in the same field evaluate someone’s research or scholarly work.
The new study looked at 386 sedentary adults who were also overweight and had high blood pressure. More than one-third of them reported having trouble getting adequate and high-quality sleep. The participants were divided into four groups. One group, which acted as the control, did no exercise. The remaining groups completed three 60-minute exercise sessions per week. One group was assigned resistance training only. This consisted of working the major muscle groups on 12 different weight and resistance machines. One group did only aerobic exercise, choosing from stationary bikes, treadmills or elliptical machines. And the third group did a combination of the two – 30 minutes of resistance training and 30 minutes of aerobic activity.
At the end of one year, the participants were evaluated for factors that included sleep duration, sleep quality, how long it took to fall asleep and how often their sleep was interrupted. Each group, including the control group, saw improvements in sleep duration. However, the resistance training group, with an increase in 40 minutes of sleep per night, had the best results. The aerobics-only group saw their sleep increase an average of 23 minutes per night, while the mixed exercise group got an additional 17 minutes per night. The study participants in the control group, who did not exercise, reported a gain of 15 minutes of sleep per night. When it came to sleep efficiency, which is the percentage of time that someone spends asleep while in bed, only the resistance exercise and combined exercise groups saw improvements. The sleep efficiency of the aerobic exercise or control groups remained the same.
While interesting, it’s important to remember these findings are preliminary. We would hate for them to cause anyone to give up aerobic activities, which improve lung function, cardiovascular health, mood and stamina. For those who may be inspired to add resistance training to their exercise regimen, the weight machines used in the study are not the only option. Resistance exercise can also be done with free weights and elastic resistance bands. You can also harness the weight of your own body by doing pushups, squats, lunges and chinups. Not only do resistance exercises build strength, they also improve bone health. And if your sleep improves, you can consider it a bonus.
Send your questions to askthedoctors@mednet.ucla.edu.