Night shift workers: When to exercise… and when not to

Night shifts are not normal. Because of this, they produce all sorts of questions that the typical day walker might find strange – or at least chalk up to overthinking. Questions like “When should I eat?”, “Should I sleep right after my shift, or stay up for a bit?” and “What time should I exercise?”

But questions like these are far more important for night shift workers. In order to cope with our abnormal schedules, we need to pay more attention to how our choices affect us.

One of these questions – one I’ve seen many times – is some variation of the following:

Can I exercise after my night shift?

Generally speaking, this is a bad idea. There are a few reasons for this:

1. Night shift disrupts our circadian clock, which is why night shift is associated with a number of negative effects on health. Delaying sleep after night shift causes sleep to occur at an even more inappropriate time, furthering circadian disruption.¹

2. When we delay sleep after night shift, we’re also exposed to more light (from the sun, bright gym lights, etc.). Light exposure at this time of day advances our circadian rhythms, suppressing melatonin and making it harder to sleep.

3. Exercise temporarily raises heart rate, cortisol, and body temperature. All three should be low for quality sleep. Most sleep experts recommend allowing two to three hours to cool down before bed – not good if you’re hoping to minimize circadian disruption. In fact, a recent study recommends shift workers leave at least five hours between exercise and sleep.²

So when is the best time to exercise?

Any other time basically; some time between when you wake up and when you go to work.

There’s even evidence suggesting afternoon is when cardiovascular efficiency and muscle strength are highest³, making it ideal for intense exercise sessions.

Or, if possible, consider using breaks during your shift for brief bouts of exercise. Not only is this an efficient use of your time, but it can also increase your alertness as much as a cup of coffee⁴ – without the drawback of caffeine’s long half-life.

If you must…

That being said, if you absolutely can’t find another time, exercise in the morning anyway. The benefits gained from regular exercise are too great to neglect. Plus, there are things you can do to cool down faster in preparation for sleep:

Watch your supps

If you’re a fan of pre-workout supplements, ensure your stack doesn’t contain caffeine. It stays in your system for hours and will ruin your sleep quality.⁵

Light exposure

Retreat to the darkness as soon as the exercise session is over. If light is unavoidable, wear blue blockers and a brimmed hat.

If you’re not sure why this is important, see What is Blue Light and Why is it Harmful?

Hot or cold?

Counterintuitively, a warm bath or shower can help you cool down before bed. In response to the heat of the water, blood moves away from your core, toward the extremities to help remove heat from the body. The key is to leave enough time for the temperature drop to occur. As little as 10 minutes, 1-2 hours before bed, has been shown to significantly reduce the time it takes to fall asleep.⁶

The sudden temperature drop brought on by a cold shower or ice bath, on the other hand, may cause a fight or flight response, producing an alerting effect. Though, anecdotally, I’ve heard people use ice baths to help with sleep as well. In either case, timing is probably the key factor, along with finding what works best for you.

Drinking cold water, or eating crushed ice can also be effective.

Breathwork

Elicit the relaxation response with breathing exercises

“Deep abdominal breathing encourages full oxygen exchange — that is, the beneficial trade of incoming oxygen for outgoing carbon dioxide. Not surprisingly, it can slow the heartbeat and lower or stabilize blood pressure.”⁷

Focus on your breath with breathing techniques such as diaphragmatic breathing or 4-7-8 breathing.

The rest

And, of course, there’s the sleep advice to follow whether you exercise or not:

How to Sleep During the Day: A Guide for the Night Shift

How to Sleep During the Day: Part II – Things to Avoid

 

Although time of day matters, exercise is not something to avoid.

 

Stay healthy-

Jason Glenn

Photo by Fitsum Admasu on Unsplash