What's the best time to exercise?

Monday, May 28, 2007
One of the few givens in life is that regular exercise is a good thing to do, but finding the time is the problem — many of us just slot it in whenever we can. So does time of day really matter when it comes to exercise? And if it does, what's the best time — morning, noon, or night?

To find out, Leila McKinnon and two mates are going to radically alter the time of day they exercise. They'll do this for two months and then see if it's affected their weight and fitness.

The test

Leila's first partner in crime is 28-year-old Georgina Kelly. She usually goes to the gym after work and thinks changing the time will be quite challenging.

"I think it would be hard for me to get up in the morning because I really do like to sleep in. I could do it but it would be a bit of a struggle — I think I'd need someone with me," says Georgina.

Our next candidate is Amy McFadden. She doesn't have an exercise routine right now: "I wake up in the morning and think, "Great I should go for a walk, I should go for a run and then I turn over and get another hour's worth of sleep."

The most Amy does is a little cursory walking in the afternoons, so she'll be making a massive change in her exercise regime.

Leila is a morning person: "That's when I like to do my exercise but that's all about to change when we swap our exercise times around."

At the University of NSW, Associate Professor Steve Boutcher has spent five years researching fat loss and exercise.

"We have a lot of information on what happens when you exercise in the morning but nobody's actually conducted any kind of trial over time — exercise in the morning versus lunchtime or night — to actually see if that is different. There's a lot of evidence to suggest it will, but we don't actually know and hopefully our little study will point to that," he says.

So before we get started, Associate Professor Boutcher's assistant Sarah will measure all their vital statistics to get a base line for the test. The professor will then take all these numbers and compare them to the results he gets when the girls do the exact same tests in eight weeks' time.

  • Georgina, who's an evening exerciser, is going to switch to exercising for eight weeks at lunch.
  • Amy gets the short straw — she's switching to morning.
  • Leila, who's the early morning person, is going to switch to evening.

No one is exactly thrilled about these changes — but anything for science!

A few weeks into the test …

Georgie used to do evenings and is now exercising at lunch times. We've sent her to our old mate, Rob Roland Smith, also known as The Sandhill Warrior, for some heavy duty training sessions.

It looks like torture but Georgie's thriving on it!

"I actually really like working out at lunch because it gives me time to clear my head after having a busy morning and then I can sort of go back to work in the afternoon just refreshed."

The Sandhill Warrior's also a big fan of the midday work out: "Lunchtime is the perfect time for people, especially that work in the city, to train. It heightens your reflexes, it increases blood flow to the brain — but probably the most important is it's a great stress release."

Meanwhile, Amy has gone from doing practically nothing to a full-on morning workout three or four times a week. She's finding it tough but rewarding.

"I wouldn't say I ever look forward to the exercise but it's really great once I'm in the session and once I finish the session to then toddle off to work knowing that I've done an hour's worth of exercise," says Amy.

We know the Sandhill Warrior loves exercise at high noon, so what does he think about morning exercise?

"Personally I love training in the early mornings. To me and to those people that I work with in the early mornings it wakes you up for the day," he says.

It's Leila's turn to exercise. For three weeks she's been on the twilight shift which is taking a bit of getting used to. So what does the Warrior think?

"The optimal time for training is the 90 minutes before 6pm or the 90 minutes after 6pm and the reasons for that is that your body temperature is high. We've put in a day's work and our body is ready to move, our body is ready to exercise."

Okay, so let's just say that for the Sandhill Warrior anytime is the right time to exercise!


After eight weeks, it's time to see how a change in exercise habits has affected the girls' fitness and weight.

Leila's in California so is getting her test done by Professor Holden Macrae at Pepperdine University. The professor will run her through the same strength, muscle tone, body fat and weight tests that she did eight weeks ago.

Body fat: down to 23 percent
Strength: 38kg force
Weight: 64kg (lost one kilogram)

Despite Leila's fears, it seems exercising at twilight has actually made quite a difference.

Professor Macrae: You went from 32 percent body fat down to 23 percent body fat.
Leila: Really?
Professor Macrae: So whatever training you did worked really well, so that's excellent.

That's not all — Leila's strength is way up, by about a third, and she even lost a kilo.

But what about the girls back in Sydney?

Body fat: down to 22 percent
Strength: 33kg force
Weight: 59kg (gained one kilo) — which the experts tell us is all muscle.

The good news for Georgie is that her change from evenings to lunchtimes has really paid off.

No doubt about it. Georgie's a convert: "I'm actually really enjoying going out at lunch so I think I'll definitely stick to it."

Strength: 24kg force
Weight: 80kg (lost four kilograms)

It's been two months since Amy swapped her couch potato lifestyle for intense morning work outs. Has it all been worth it?

"The overall results are very impressive. You lost over four kilos in weight. Most of that is fat," says Associate Professor Boutcher.

So the key message from Amy's results is that exercising before breakfast is definitely the best time to bust fat!

"Before I came today I wasn't sold on the idea of getting up at the crack of dawn but I'm really pleased with the results I got today," says Amy.


So what's the verdict on the best time to exercise?

"We now think that if you fast in the morning, the body is voraciously burning up fat, so that when you exercise after that it continues to use fat. So exercise in the morning is the optimal time to lose fat," says Associate Professor Boutcher.

You heard it. If you want to lose weight, get cracking first thing in the morning. Studies show this is the best time to shed those extra kilos.

Now, when Leila changed from morning to evening she gained a massive 35 percent increase in strength. Professor Boucher says that was no coincidence. In fact, it's the reason weightlifters work out in the evenings: "The optimal time to lift weights is late afternoon or early evening and this is because the muscles are warmer and certain hormones that are necessary for muscle resistance work are optimal."

Choosing the best time really depends on what you want from your exercise and what suits your lifestyle.

The truth is, any exercise is better than none at all — so no excuses, get out there and do it, anytime you can.

Fast facts

  • Is there a bad time to exercise? It's not good to exercise right before bed because it raises our core temperature and increases our hormone activity, making our bodies hot and restless.

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