One of the many ways in which my wife and I exhibit incompatibility is in the matter of exercise; specifically, when best to get it. No, stop it, really. She's an incorrigible seeker of daylight; the soul of morning cheer. I warm up in the afternoon and expire around 10.
All my life I've been hearing and reading about the invigorating, energising effects of morning exercise. And I've tried it, many times, in many forms. But all I ever got from walking, running, cycling or swimming before work was the urge to curl up like a dormouse and sleep until lunchtime. Which apparently is grounds for dismissal in some of the less tolerant corporate cultures.
I appreciate and welcome the diversity of human experience. Some people gain a perverse buzz from their pre-work workout and that's great as long as they deodorise effectively and keep the noise down. For me, night-time is the right time, as Ray Charles put it (no jokes, please).
But until now I've always secretly believed the pro-morning propaganda and envied the bright-eyed bunnies and their ability to power-walk themselves into a lather of sweaty enthusiasm and somehow stay on that energetic plateau for hours. I felt that if only I could be a morning person, I'd cross the invisible fitness threshold separating me from boundless vigour and irritating, relentless positivity.
I should have known somebody would research this – and they have. The results aren't conclusive, but they're reassuring, in that they support whatever you're doing already – as long as you're already doing something, that is. More importantly, they support what I'm doing.
There are some persuasive reasons for morning exercise. You're more likely to form an enduring habit in the morning. And 45 minutes of brisk walking has been shown to reduce the desire to eat.
On the behavioural side, it's allegedly easier to make time in the morning. And by raising your heart rate in the morning, you'll burn more calories throughout the day and stay more alert while you're at it.
Bingo. Conversely, your body temperature is at its lowest in the early morning and energy levels are lower. You may not exercise as vigorously and, as a result, may burn fewer calories than you would later in the day.
And things do get interesting later in the day. For most people, body temperature and hormone levels peak at 6pm. A good walk three hours before or after the peak will give your your best workout for both endurance and building muscle; your muscles are warm and flexible and perceived exertion is lower, with the result that, all things being equal, you should feel inclined to walk faster and further.
The appetite-suppressant effect will operate on your dinner if you walk beforehand, and as long as you don't exercise heavily within three hours of bedtime, the effects should promote sleep.
There are broadly in-between arguments for and against the in-between times of day, but you don't need them, because if you're lucky enough to have freedom of choice or spontaneity, you're probably already enjoying it. It goes without saying that the right time to exercise is whatever time you exercise. Put less fridge-magnetically, there are pros and cons, but it's nearly all pros.
Conor O'Hagan is editor of the bi-monthly Walking World Ireland magazine. www.walkingworldireland.com