When you run for a long time on your job, commuting home is slow, cooking dinners takes forever (you promise to stop ordering takeaways), and it is normal to try a quick workout before crashing. It's better than not exercising, right? Unfortunately, a recent study is bad news for you: Exercise shortly before bedtime can have a negative impact on your sleep.
After monitoring 14,689 people for one year of exercise, sleep and heart activity, an international researcher revealed that exercising within four hours after sleep is associated with longer sleep, lower sleep, lower quality of sleep, higher night resting heart rate, and lower nighttime nighttime heart rate variability—a nighttime heart rate variability typically associated with health risks.
“Exercise exercise at night can keep the body highly alert, which is why public health guidelines previously advised not to get too close to bedtime.”
While some previous studies challenged these guidelines by suggesting that late exercise does not always disrupt sleep, Leota claims that the studies “rely rely on small sample sizes and laboratory environments and rarely involve exercises that cause a large number of cardiac metabolic needs in the body,” he added, raising questions about the effectiveness of its results.
To elucidate the justification of these public health guidelines, Leota and colleagues conducted a new study published Tuesday in the journal Nature Communications. The team monitored 14,689 study participants with multi-sensor biometric devices and collected data from 4 million nights to investigate potential associations between late-stage exercise, exercise intensity, sleep and cardiac activity during sleep.
Their analysis of the data introduced age, gender, season, workday, fitness level, and how participants sleep the night before. The result will be a later, hard workout linked to the above signs of impaired sleep health.
“Enjoyment at night – especially involving high levels of cardiovascular strains – may disrupt subsequent variability in sleep, resting heart rate and heart rate, thus impairing critical stages of the recovery process,” Elise Facer-Childs, senior author of the study, also from Monash University's School of Psychological Sciences.
Exercises considered “hard” are exercises that lead to continuous improvement in respiratory rate, heart rate, body temperature and psychological alertness, such as high-intensity interval training, long-distance running or football matches. So, “If you exercise during four hours of bedtime, people can choose to have a short, low-intensity exercise, such as jogging or swimming, to minimize sleep damage and relax the body.”
The study ultimately has important implications for sleep health, shedding light on how late night exercise affects critical eye closure and gives individuals the best rest.
