WHEN TO WORK OUT

THE more active you are, the more glucose — and stored glucose (i.e. fat) — you turn into energy. So is there an optimal time of day to exercise for maximum calorie burn?

I’m delighted to say that there is. In general, our muscle strength peaks between 4pm and 6pm, which coincides with our peak in core body temperature.

Increased body temperature will increase our metabolic (calorieburning) rate — and increased muscle power will mean we can do more, and so burn more energy that way, too. Even when resting, we burn about 10 per cent more calories in the late afternoon and early evening, compared with the early morning. And if you’re an evening type, exercising later in the day confers even more advantages!

A study involving athletes showed that larks, doves and owls (see previous page) all performed better as the day progressed, but owls did the best later in the day, with as much as a 26 per cent difference between their abilities at 7am compared with 10pm. That said, there are upsides to getting moving before breakfast. On an empty stomach, the body is still using stored fat as fuel, so early exercise will burn more fat.

The bottom line is: you’re more likely to burn stored fat first thing, but exercising later on will allow more vigorous exercise — and so more calorie burn overall. It’s a win-win, with advantages whatever time you work out.

Or you could hedge your bets, like some of my colleagues, who do a daily morning exercise of about 20 minutes, followed by a 30 to 40-minute block of activity later on.