Working Out Before Bed: Is Late Night Exercise Right For You

by Chris 'The Kiwi' Ashenden - 2 years ago

We all know the importance of getting out there and staying active, but it can be hard to find the time. What about working out before bed? Does that have any negative repercussions?

Nike tells us Just do it. Under Armour says I will. And Adidas advises us that Impossible is nothing.

Come on, you giants of the sporting world – a little more info is required!

Does the timing of your workout matter greatly? Specifically, how about working out before bed?

If you’re the type of person who likes a 10km run in the dark at 10pm or secretly slips off to the local gym to lift weights at midnight, is it doing you any good? Or harm?

We know how important decent rest is to health and fitness. And most of us know that exercise improves sleep. So how does the timing and type of exercise affect this? Does working out before bed result in worse quality of sleep as is often claimed?

Would it be better to set the alarm an hour earlier and miraculously transform yourself into a morning workout freak, no matter how scary that sounds?

If you do decide that the rumors are a load of baloney and working out before bed works best for you, what should you be focusing on? Aerobic or anaerobic? Weights, cardio, yoga… What? Is there a difference to its effect on your sleep?

That’s a lot of questions, and the answers can be a little complicated.

So, in this article, I’ll share findings from my own research. In the process, hopefully I can save you some ‘screen time’ researching – time that can be put to better use. Like working out.

More importantly, I hope to help you make some important decisions regarding the future of your exercise.

And I’ll show you how you can test your response to working out before bed and monitor results so that you can decide not only about timing but the type of workout you should be focusing on.

Fact: Exercise Does Improve Sleep

Let’s start with something we do know: regular physical activity at any time of day is good for your health – whether you’re working out before bed or first thing in the morning.

Furthermore, a large body of scientific evidence shows that exercise will generally improve sleep and may even help with sleep issues like insomnia.

It is thought that the brain’s response to the stress caused to the body during exercise, combined with the rise and fall of body temperature and the positive effects of exercise on stress levels, anxiety, and mood (which can all harm sleep patterns) are thought to contribute to better quality sleep.

Not only does regular exercise aid more restful sleep, it also increases the duration of sleep and the time spent in deep sleep. This is seen as the most important phase of sleep for general health, boosting immune function, supporting cardiac health, and relieving stress and anxiety.

Sleep is generally understood to be ‘good quality’ when it’s easy to fall asleep and wake up, and when the sleep is continuous and long enough.

Evidence Supporting The Benefits Of Exercise For Sleep

The Sleep in America poll by the National Sleep Foundation (NSF) in 2013 examined 1000 participants, who self-reported their sleeping habits.

It found that:

83 percent of people who exercised at any time of day (including late at night) reported sleeping better than those who didn’t exercise at all.

The study also reported that:



Over half of vigorous and moderate exercisers slept better on days when they worked out than they did on days with no exercise.

This backs up previous studies that have long reported the beneficial effects of physical activity on physical and mental health, and on sleep.

Interestingly, the NSF poll also found that people who don’t exercise are more likely to take medicine to help them sleep.

In a very recent study entitled, “The Effect of Resistance Exercise On Sleep“, there was some interesting insight into the connection between resistance training, aerobic exercise, and sleep.

Thirteen studies were included in a systematic review of literature, to determine the acute and chronic effects of resistance exercise on sleep quantity and quality.

It was found that:

However, studies comparing the effects of resistance training and aerobic training on sleep are rare – and, as we shall see a little later, those comparing the effects of different types of exercise before bed are seemingly non-existent.

Indeed, the above study noted in its conclusion:

One study from Sleep Medicine in 2010 entitled “Aerobic exercise improves self-reported sleep and quality of life in older adults with insomnia” raised some other questions.

In that study, a small group of insomniacs in their sixties were split into two groups: one remained sedentary and the other embarked on 30-minute aerobic exercise sessions three or four afternoons a week. Those who were exercising slept more soundly after the 16 weeks of the study, reporting on average 45 minutes more sleep per night.

However, some insomniacs complain that they see no benefit to their sleep, despite exercising regularly. This suggests that the relationship is not quite so simple.

Dr. Kelly Baron, sleep researcher at the Feinberg School of Medicine at Northwestern University, decided to investigate this on behalf of some of her patients.

Going back to the 2010 study described above, Dr. Baron found that, in actual fact, the sleep improvements were not recorded until 2-4 months after they started exercising. So the results were far from immediate – and it seemed to take time for the ‘stress response’ that keeps insomniacs awake to be dulled by the effects of the exercise.

And interestingly, those who had slept poorly usually reported shorter exercise sessions the following day – suggesting that sleep affects exercise as much as exercise affects sleep:

Fortunately, most of us are not insomniacs and the relationship between exercise and sleep is a little simpler. Exercise should have more immediate benefits for our sleep quality. However, we should note that it’s not the same for everyone and it’s not a simple linear relationship.

Working Out Right Before Bed vs. Any Other Time Of Day

Is Working Out Before Bed Bad? The Case Against It…

Sleep scientists generally recommend working out before bed should allow about three hours for the body to settle down before sleep. This is primarily because of:

  • The rise in body temperature above its normal 98.6 degrees: this upsets the internal body clock, which naturally lowers body temperature before sleep;
  • The difficulty in relaxing after a burst of energy;
  • The release of chemicals into the brain and body that may prevent sleep.

The American Academy of Sleep Medicine in 2001 pointed to the increased state of arousal that exercise produces as a reason for avoiding it before bedtime.

Lisa Medalie, a behavioral sleep medicine specialist at the University of Chicago, tells her patients with sleep disorders:

Another typical piece of advice you’ll see is:

“You should not exercise in the late evening or just prior to going to bed. Exercise at this time of the day will not give your body enough time to cool down and calm down, making it difficult to sleep…. Bottom line: Try to exercise three to six hours before bedtime to get the maximum sleep benefits.”

On the face of it, a raised heartbeat, high body temperature and natural stimulants flooding the body may not seem very conducive to a restful night’s sleep. It may not be surprising that you see warnings that working out before bed could lead to insomnia.

However, real ‘evidence’ that exercising before bed is bad for you is actually thin on the ground. It’s mainly anecdotal – and, like with anything anecdotal, it varies from person to person.

A quick search through online forums and you’ll read accounts from people who’ve attempted working out before bed who say that their brains are too active, their heart rate is too high, or they feel too hot to sleep.

But one small Japanese study was set up in 2013 specifically because studies had failed to show that moderate pre-sleep exercise produces a negative effect on sleep (onset).

This study looked at more vigorous exercise and its impact on sleep onset and compared it to moderate exercise.

The results indicated that vigorous exercise before bed might disrupt the onset of sleep.

The onset of sleep was delayed for an average of 14 minutes, which might be significant for some people. However, the study didn’t measure the quality of sleep through the night after exercising before bed – which is what most readers may be more concerned with.

Another 2014 study from Appalachian State University looked at the effects of working out in the morning on sleep and nocturnal blood pressure. It found that:

It concluded that:

However, this study was mainly focused on people susceptible to hypertension so it may not be best to use it as a guideline for the exercise regimens of fit and healthy individuals.

Is Working Out Before Bed Good? The Case For It…

Nowadays you’re just as likely to read about people relating the pros of working out before bed as the cons.

What’s more, studies seem to back up the notion that working out before bed is not going to keep you up all night – and is just as healthy for you (if not healthier) than working out in the morning. It doesn’t appear to disturb sleep patterns.

One study found that muscular function and strength is at its peak in the evening and the body is better able to take in and utilize oxygen at that time, resulting in slower use of the anaerobic reserves.

So, it is certain that time of day should be taken into consideration for testing workout efficacy.

In a Finnish study from 2011, subjects were found to sleep just as well on nights when they had exercised vigorously for 35 minutes right before bed as they did on nights when they skipped exercising completely:

“The results indicate that vigorous late-night exercise does not disturb sleep quality. However, it may have effects on cardiac autonomic control of heart during the first sleeping hours.”

The problem is that this only suggests that working out before bed is no worse for sleep than no exercise at all. Most of us knew that already.

It doesn’t get us any closer to the question of whether exercise directly before bed is better or worse for sleep or general health, than exercise at any other time of day; and the effects of different types of exercise (cardio or weights) was not studied.

In the National Sleep Foundation study referred to earlier, only 3% of late-day exercisers said they slept worse on days when they exercised, compared to days when they didn’t.

Furthermore, the NSF poll also reported on differences in self-assessed quality of sleep for different exercise times in the following groups:

  • Exercise more than 4 hours before sleep
  • Exercise within 4 hours of sleep

Of those people who exercised more than 4 hours before sleep, 81% reported fairly or very good overall sleep quality. This was 5% higher than those who exercised within four hours of bedtime. It’s important to note though, that both figures were very high.

Again though, the question asked wasn’t how exercisers slept after working out before bed compared to when they worked out in the morning – or other time of day. Four hours before bedtime might be around 6pm – which can hardly be considered before bedtime.

Also, there was no analysis of the type of exercise – cardio or weights – and how that might have affected sleep quality.

Unfortunately, this seems about par for the course.

There are some studies that look at the relative effectiveness of morning cardio and evening cardio but no comparisons with weight training.

One of the cardio studies from 2012 entitled, “The Effect of Training at a Specific Time of Day: A Review”, observes that training performances peak in the late afternoon.

This backs up other evidence that strength training later in the day is more beneficial than working out in the morning – because your body temperature is warmer and exercise is perceived to be easier. But again, nothing on the effects of a strength workout right before bed.

It goes on to suggest that regular aerobic training in the evening may enhance performance further. Again, no investigation into how regular aerobic workouts right before bed affected either performance or sleep.

As the New York Times article about Dr Baron (referred to above) dictates:

“It is impossible to yet know the sleep-related impacts of workouts of different types (like weight training), intensities or timing, including morning or late-evening sessions”.

Why? Well, it seems that the studies simply haven’t yet been done. That’s why trying to find them on Google may result in a wasted hour or two – I’ll save you the trouble.

Aerobic And Anaerobic Exercise

Quite apart from the lack of comparisons between cardio and strength training late at night before bed, there is even a distinct lack of research comparing the results of aerobic and anaerobic exercise on sleep full stop.

As we’ve seen, plenty of studies examine the correlation between sleep and exercise in general – and also the differences between the two types of exercise. But little else.

Some interesting insights could be gained by testing whether the type of exercise, aerobic or anaerobic, affects average nightly sleep differently?

It stands to reason that, if aerobic and anaerobic exercise benefit health in different ways, that they may also affect sleep in different ways.

Aerobic (cardiovascular) exercise pushes the entire body, working out many muscles and raising the heart rate; anaerobic exercise pushes only part of the body at a time, and the heart rate is not so dramatically affected.

It would be interesting to scientifically measure how this affects the restfulness of sleep.

Working Out Before Bed: How To Know If It’s Right For You…

In the absence of studies that have specifically tested the effects of aerobic exercise versus anaerobic exercise before bed, what can we do?

Like any curious individual looking for the best results, you can be the guinea-pig yourself. Test it out and see what works best for you.

To help with your experiment, I’ve put together some suggestions, and a tracking sheet, which you can download free below. Note that your starting point for any experiment will greatly depend on where you’re at presently with your workout routine.

If you’re an experienced, habitual, and vigorous exerciser, usually working out three or four times per week with cardio and weight-training, you can try my suggested workouts.

If you’re less experienced, adjust the experiment to match your current level.

It’s not exactly scientific, but after the three-week experiment, you should have excellent insight into how your own body reacts to working out before bed.

Pro-Tips: Finding The Ideal Gap When Working Out Right Before Bed

1. Noam Tamir, founder and program director of TS Fitness studio in New York, advises:

“Most people experience a drop in those stimulating hormones like cortisol and adrenaline within an hour or so after they work out, which puts your body in that relaxed, ready-to-sleep state.”

However, if a 45 or 60-minute break between exercise and sleep doesn’t work for you, repeat the experiment leaving bedtime until 90 minutes after your workout.

2. If you really want to start introducing night-time workouts into your routine and get the timing spot on, play with the times over an extended period and find out what works best.

3. Try using a personal activity monitor – this may help you understand how your sleep is impacted by exercising at different intervals before bedtime.

4. Need extra fuel? We all know that exercise eats up the nutrients you’ve taken in – but these reserves are further depleted during the night. You need a plan for nutritional recovery. Introduce a late-evening snack before your workout to ensure that you’ve got the energy to last the distance. And, of course, stay well hydrated, as water is lost during the night.

5. Try taking cool showers after working out at night, to help your body temperature return to normal quicker.

Another important point to bear in mind: do it enough and your body will adapt to your workout time, and prepare the muscles for action, be it morning, noon, or night.

By running these experiments with your workouts, you’ll almost certainly learn more about the type of exercise that your body reacts well (or not so well) to late at night before sleep.

And you may just be able to rule out (or rule in) working out before bed as an ongoing part of your daily routine.

Just Starting Out With Working Out?

Firstly, read “Beginner Workouts—From Swimming To Weight-Lifting” for some general tips on how to get started with a workout routine that’s right for you.

If you’ve decided that you want to give working out at night a go, apply the routine you’ve decided on but take it slowly. Start with ten minutes. And leave it a while before you go to bed afterwards: give yourself time enough to cool down, relax, and for body temperature, heart rate, and adrenaline/cortisol levels to return to normal.

Remember – even short, light workouts will stress your body at first, if you are not used to exercise.

Bottom Line: Should You Work Out Before Bed?

Those poor ‘fools’ you see working out through the 24-hour gym window when you’re on the way home from a big night out – are they really so foolish?

Just doing it is certainly better than not doing it but should we really be going to such extreme lengths to exercise?

Well, yes. It’s really that important.

For many people, fitting a workout into an already-hectic daily routine is a big challenge. If you’ve been following the same routine for years, it may be tough to change. And if there’s no compelling reason to change, why would you?

‘Horses for courses’

Whether you’re a ‘morning person’ or ‘evening person’ may be out of your hands – much of it is determined by genetics.

But some people choose working out in the morning to guarantee that the workout actually happens – before interruptions to the day take the opportunity away. Others believe that working out in the morning is the only way to commit to it in the long-term. And that’s OK.

Equally, if the thought of getting up at 6AM on a cold December morning and heading for the local gym has always filled you with dread, there’s no compelling reason to start doing that now; nor is there any reason why you should give up a lunchtime workout for a midnight one; but equally there’s probably no reason why you should replace working out before bed with an earlier session.

If you’re working out at night, you probably do so for a number of reasons: it may be the only available time in your schedule; it may be to overcome other temptations (like going out drinking?); it could be that the gym’s too busy at other times; you may have more energy at night; or it may simply be because you prefer running in the cool darkness of night-time.

Either way, the main takeaway is this: The best time to work out for most people is whenever you’re most likely to do it.

Exercise at any time of day is beneficial – and you’re more likely to commit to it if it fits in well with your lifestyle and you enjoy it. A convenient time helps with that – and if ‘convenient’ to you means midnight, so be it.

Work It Out For Yourself!

There is a lack of scientific evidence to compel you to change either the time you exercise or the nature of it.

Over to you Nike and Adidas. Perhaps it’s time to run the studies so that we’ll see new tag-lines in the future like Just do it…in the morning and Impossible is nothing … before bedtime!

Until then, I’d encourage you to experiment with cardio and weights to see what suits you best for working out before bed.

For some people, strenuous exercise before bed may delay sleep onset but the proof is in the pudding: test how it affects both getting to sleep, staying asleep, and overall quality of sleep.

Dr Stuart Quan, a professor of sleep medicine at Harvard Medical School warns:

The bottom line? Anyone who puts in 30 minutes of cardio per day and combines it with some strength training should see the benefits: it’s clear that most people (without pre-existing sleep problems) will sleep better and be fitter and healthier than someone who doesn’t work out at all.

If working out before bed works best for you and your lifestyle, then stick with it. Until the research proves otherwise…

What Next?

Get experimenting! Download my free tracking and tips below.

I’d love to hear about your own experiences with exercising before bed compared to other times of day.

After you’ve run a few tests with your workouts, why not share the results below or on our Facebook page? How does it affect your sleep – and what (if any) difference do you experience with sleep after cardio or weight training?