The pros and cons of exercising after 8pm

Exercising after 8pm can lower the risk of cardiovascular disease, but may impact sleep quality. Photo / 123RF

New research has found exercising at night lowers the risk of cardiovascular disease. One writer finds out how doable it really is.

I am a born lark. I will regularly wake up at 4.45am to go for a run. My maternal grandfather was a lark too. He was also diabetic, had a flat bum, a big nose and ended his days eating sugarless biscuits and very few potatoes. I’ve certainly inherited the flat arse and big nose, so I’d be keen not to repeat the slide into a potato-free future. So it was with some interest that I read a recent study, published in the journal Diabetes Care, that found evening exercise (defined as bouts of moderate to vigorous physical activity lasting more than three minutes) was actually associated with a lower risk of mortality and cardiovascular disease.

For a 39-year-old woman, my general health isn’t bad. I run for an hour about four times a week, I can do up my shoes without grunting, and with a BMI of 22.3, I’m well within the healthy range. It wasn’t always this way, though - for much of my life I’ve struggled to keep my weight down (I once put on a stone during a fortnight’s holiday to France) and only really enjoyed regular exercise during my late 20s.

Luckily, the researchers did consider including sedentary time, age, sex, diet and sleep duration; and still found the timing of physical activity may play a role in the future of obesity and management of type-two diabetes.

“Insulin sensitivity is down to an interaction between the hormones. Cortisol and insulin are almost inverse; cortisol breaks down while insulin builds,” explains NHS GP and personal trainer Dr Amos Ogunkoya. “We know that cortisol levels are higher in the morning and cortisol tends to hold on to fat. That means exercising later might allow you to actually do a better workout - especially as most of us have time limitations in the morning but more time in the evening.”

We know exercise has stress-relieving properties, and further studies link evening exercise to falling asleep faster and spending more time in deep sleep. So, knowing how good it is for me, could I, a sworn morning person - who frequently goes to sleep in full daylight and to the sound of young children playing outside - switch my routine around? Could I become a fitness owl?

Monday evening yoga class

Not wanting to throw myself into anything too brutal straight off the circadian bat, I opted for a Monday evening yoga class. To get there involved a short bike ride in the setting sun. Which was picturesque, until an enormous brown rat ran across my path. That’s one problem with being out and about in the evening - so are the rodents.

Somehow, the slowness of yoga - all that breathing and stretching and listening to your body - can feel frustrating to me in the morning. But after a full day of work, childcare, unpaid domestic labour and the news, I relished the idea. As a beginner, I found my muscles shaking like a Polaroid picture after even just a few seconds of downward-facing dog.

Verdict

Yoga’s seriously good for you. One 2016 study by the Rockefeller University in New York showed participants doing yoga three times a week significantly improved bone mineral density in their spine, hips and thigh bones. The slow breathing has been shown to have a calming effect on our nervous system and reduce our stress levels too - both conducive to getting eight hours of sleep, which also happens to be linked to good heart health.

Evening yoga can improve bone density and reduce stress. Photo / 123RF

Tuesday evening run

With my metabolic processes in mind, I had an extremely early dinner on Tuesday with my son to be ready for a run after his bedtime. It felt completely bizarre, bordering on scandalous, to be pulling on a pair of Lycra shorts at 8pm.

But, honestly, how else are parents to small children supposed to capitalise on all this evening insulin regulation? I may have provocatively suggested to my partner that “vigorous physical activity in the evening is widely acknowledged as a therapeutic strategy for improving cardiometabolic risk factors”, but I’m not sure it was quite the seductive line I’d hoped. So, I was stuck with running.

The problem with something as high-adrenaline as a jog down the towpath, at night, is that by the time I got home a little over an hour later, sweaty and with my pupils dilated, I was in no fit state to fall asleep.

Verdict

Despite a hot shower and cup of chamomile tea, I lay in bed for at least an hour and a half, completely unable to switch off. Indeed, studies show in order for evening exercise to improve sleep, it needs to be of a moderate intensity, not vigorous and end at least an hour before bedtime. Lesson learned.

Slower exercise definitely seems more conducive to good sleep but I don’t want to give up my running. Thankfully, Ogunkoya reassures me doing something is always better than nothing - whatever the time. “The biggest contributor to diabetes, cardiovascular disease and cancer is a sedentary lifestyle,” says Ogunkoya. “So, if you find cardiovascular exercise in the morning easy, then go with that. And maybe do weights in the evening.”

Cortisol levels, which affect fat retention, are lower in the evening. Photo / 123RF

Wednesday evening weightlifting

I am not built for strength training - I had never before attempted a deadlift and was more than a little nervous at the prospect of being crushed by a barbell. However, within a few minutes I was doing sets of six and eight deadlifts; albeit with all the grace and posture of a duck.

Unlike more cardio-intensive exercise, weightlifting lends itself to evening exercise, as you might have the stamina to build muscle but not enough energy to jump around.

Did it give me flashbacks to the horrors of Year 6 PE? You bet. Did I feel the benefit the next day? Friends, I could hardly walk.

Verdict

I would really like to improve my bone density before I start to crumble like a digestive biscuit, and studies show putting stress on your bones by doing weight training like this can improve it. Going gently is the key to reaping the stress-relieving benefits of this evening activity, without overstimulating before bedtime.

Weightlifting at night can build muscle without overstimulation. Photo / 123RF

Thursday evening barre class

I spent Thursday night working on grace and flexibility at a barre class in a gym 10 minutes away. Barre is a vicious combination of ballet, yoga and pilates, designed to turn your limbs into willow and your stomach into iron.

I ate an ill-advised quantity of lentils for dinner at 5.30pm and three hours later could be found doing the sort of plie last seen during the moon landings, only in my case I had a resistance band around my knee and was wearing leggings printed to look like the night sky.

After the relative stasis of weightlifting, it was wonderful to feel my heart rate soaring again.

Verdict

Research shows a positive link between dancers and their levels of happiness and self-esteem and I can see why. As I watched the sky out of the large windows turn inky, I felt a rush of pleasure, and with each controlled movement, I felt my stress levels lowering once again.

Friday evening swim

My local leisure centre used to run a women-only session on Fridays from 7.30pm but, apparently, they are struggling to recruit enough female lifeguards. Which meant that, as I plopped into the medium lane on my final evening, I was greeted by the sight of a man in a full-body wetsuit, floating, head down, entirely vertical and unbreathing. It was like getting into a swimming pool with a 12-stone barracuda. Every so often, while whipping down my lane in front crawl, I would catch sight of him doing something bizarre like grinding along the bottom of the pool without moving his limbs; or hanging like a bat from the water’s surface. Perhaps, I thought, he’s an aquatic vampire. Perhaps this is just what happens when you try to exercise at the witching hour.

Verdict

I have always loved swimming at night, and studies show that 30 minutes of swimming at room temperature stimulates the release of endorphins. The way it increases my heart rate without putting too much impact on my muscles or joints feels tiring, but in a deeply pleasant way.

Logistically, evening exercise was a challenge but once scheduled, I found myself feeling quite smug that I’d snatched this otherwise blank time to be sweating, panting, moving and laughing in the company of others. I’m not sure if it was knowing that it was doing wonders for my heart, or if it’s the thrill of breaking my usual routine - but I even got the occasional hedonistic rush of being out and sweaty and excited in the dark.

Night swimming releases endorphins, promoting a pleasant tiredness. Photo / 123RF