Strength Train for Sleep and Heart Health Benefits

April 25, 2022
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Fitness Research Spotlight

Today, 1 in 3 adults do not regularly get the recommended amount of uninterrupted sleep they need to protect their health. An estimated 50 to 70 million Americans experience a sleep disorder including trouble falling asleep or staying asleep.  So, how do you get the night’s rest you crave?

Participating in a healthy activity such as strength training is good for the body and mind.  A top lifestyle risk factor for heart disease is exercise. When we think of heart health, the kind of activity that comes to mind tends to be aerobic exercise, such as walking, running or swimming. (It’s often called “cardio” after all!) More recently, studies are highlighting the role of resistance exercises for heart health. For example, reviews on the topic confirm that strength training for about an hour a week improves heart health. It’s easy to think of strength as something static, you either have it, or you don’t. New research suggests we should seek out challenging physical movements throughout our entire lives. The benefits go beyond bigger muscles!

One of the less-appreciated lifestyle factors that impacts the heart is how we sleep. Large-scale studies confirm the link between better sleep and cardiovascular health. For example, a 2018 study on almost 61-thousand adults over age 40 found that poor sleep raises heart disease risk. And studies from 2019 found that poor sleep produces changes in the body that are “strongly predictive of future heart disease risk.”

The importance of sleep and exercise for heart health is undisputed, but new research uncovers what kind of workout is best for high quality sleep. 

Aerobic exercise promotes better sleep

A wide range of individuals benefit from aerobic exercise in studies that measured sleep outcomes. For example, studies in those with sleep difficulties suggest that 4 weeks of aerobic exercise is sufficient to enhance relaxation and improved sleep quality. And longer randomized clinical trials confirm the impact of cardio exercise on sleep and wellbeing. 

Many have long-term issues initiating and maintaining sleep, as in the case of insomniacs. But if we expose individuals who have chronic insomnia to regular aerobic exercise, studies show their sleep times rapidly improve.

Another group that tends to have insufficient sleep are students at colleges and universities. In these populations, 4 weeks of aerobic exercise of moderate to high intensity is enough to improve all aspects of sleep quality. In this study, very mild low-intensity cardio exercise had no effect. This suggests that workouts that offer little challenge have more subtle effects. It also indicates that challenge may be a key component of sleep-promoting exercise. 

Regular resistance training may work better

Strength training “improves all aspects of sleep” according to randomized controlled trials. But which is better for sleep, aerobic to resistance exercise? 

Researchers at Iowa State University tested this idea using different forms of exercise and monitor sleep quality. For one year, adults were assigned to a either a no-exercise or exercise group. In the exercise group, individuals completed either aerobic exercise, resistance exercise, or both.

The study found that average sleep duration increased by almost 40 minutes in the resistance exercise group. In contrast, sleep time was only extended by about 23 minutes in the aerobic and 17 minutes in the combined group. Sleep efficiency was most improved in the resistance and combined groups, and was not improved in the aerobic exercisers. (Efficiency is related to whether we stay sound asleep during the night.) Taken together, this indicates that training for strength may be even better than cardio when it comes to sleep.  

The study authors remind us that, “if your sleep has gotten worse over the past two stressful years, consider incorporating two or more resistance exercise sessions into your weekly routine.” 

As Treo’s Global Wellness Researcher, Karlie uses recent research findings to support healthier daily habits. Karlie earned her doctorate in Neuroscience and Behavior and bachelors in Health and Exercise Science.