The perennial question of whether it’s better to work out in the morning or the evening has been the subject of recent research, this time with a focus on its effects on sleep. So, what’s the verdict?
According to researchers from Appalachian State University, it’s the early bird who catches not only the worm but also the sleep related-benefits of working out. Assistant professor and lead study author Scott Collier, PhD, said “Insufficient sleep threatens our country’s health by contributing to chronic diseases, such as diabetes, cardiovascular disease and obesity. Exercise is proven to improve the quality of sleep, and our team wanted to see if the timing of exercise could maximise these benefits.”
The research team looked at the effects of exercise timing on the sleep patterns of six male and three female study participants. Each participant was monitored during half-hour treadmill sessions at 7am, 1pm and 7pm on different days. During the night following each study period, participants wore sleep-monitoring headbands to measure quality of sleep and sleep stage time.
The results showed that when exercising at 7am, the participants achieved significantly better sleep than when they worked out at lunchtime or in the evening.
Collier said, “Our research has shown that well-timed exercise can elicit even greater sleep quality. These findings, if the results of the sample hold true for the general population, can help exercisers gain even greater benefits from physical activity.”
Circadian rhythms are biological phenomena within the body with a period of activity lasting 24.2 hours. Examples include the sleep/wake cycle, hormone production and core temperatures. During the time when the body typically falls asleep, core temperatures usually decrease and production of a hormone called melatonin increases. Exercise produces the opposite effect, with core temperatures rising and melatonin production decreasing, and this affects our ability to sleep.
Sleep is an important tool for athletic recovery, and based on this information we might choose to program the hardest workouts in the morning. However, due to other circadian rhythms reaching their peak in the late afternoon or evening, this is generally considered the time for peak athletic performance. Another reason to train in the morning is to take advantage of the mood enhancing hormones released during exercise for the rest of the day. Endurance capabilities seem to be relatively stable throughout the day.
Interestingly, circadian rhythms seem amplified in fit individuals when compared with sedentary individuals and those over 50 seem to be more inclined to train in the morning. Despite this information about circadian rhythms, in the average person concerned with health and fitness, it is more important to achieve total exercise times per day or week than to consider what time of day the exercise is performed. In those completing a high volume of training, sometimes when it comes down to the choice between more sleep or training, sleep can be the more beneficial choice as the recovery and muscle repair benefits of sleep can outweigh the gains made through further training.
You may have discussed this issue without knowing it’s actually ‘a thing’. Circadian rhythms also depend on the ‘chronotype’ of an individual, with some naturally preferring to wake up earlier and end the day earlier leading to better performance in the mornings. Others prefer to sleep until later and stay awake later and therefore perform better in the evenings.
When it comes to sleep, other factors can also influence the quality. High training volumes can impact sleep quality in athletes, and lack of sleep can then be detrimental to immune function, metabolism and physical performance, amongst other things.
Melatonin is a neurotransmitter involved in the sleep/wake cycle and some research has been conducted into dietary interventions that can increase the amount of melatonin and therefore improve sleep. Studies have shown that consumption of a high carbohydrate meal before sleep can lead to increased REM sleep, although consuming a solid meal within three hours of sleeping can increase the time taken to fall asleep, particularly within the final hour before sleep.
In those suffering from some degree of sleep deprivation, napping can be beneficial to performance as it increases total sleep time. This is particularly relevant in those who must train or perform in the afternoon.
Whether you are a morning or night person, an athlete or a weekend warrior, sleep is an essential part of our life that significantly impacts our daily functioning and athletic performance. The most important thing is to achieve enough time spent sleeping, and to achieve your exercise goals. Manipulating sleep time, exercise time and diet can be valuable tools in achieving this.
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