Is there an optimum time to exercise?

I was told that I should vary my exercise and change my timing occasionally to fool my body clock....I am not sure how it works but apparently the body gets used to being fed and exercised at certain times so it helps to confuse it now and again by eating and exercising when it least expects it. This can kickstart your metabolism and weight loss to get going again. Has anybody else heard that?

as a mother of 2 working 2 jobs and also running a soccer league i have started the 5am work out and I have to say it sucks when the alarm goes off but i feel fabulous when i am done and they day seems that much better

The "optimum" time is whenever you have enough time, energy, and focus to fully commit to your workout. For some people, that's first thing in the morning. For others, it's some other time. If you have to drag yourself through a workout at 5 AM, it's going to be far less effective than if you waited until your mind and body are better prepared for it.

Working out in the morning is optimal, but working out at any time is much better than not working out at all.

That's not actually correct. The preferred time physiologically is around 3pm. It's when you're less likely to release cortisol in response to exercise, and therefore more likely to get a) the effects of training you're hoping for and b) recover quickly.

Saying that, training at any time is fine. Competitive swimmers train both at early mornings and late at night. Train whenever suits you best.

The tricking your body thing that others have mentioned doesn't work either.

I saw on Doctor Oz's show that he stressed that you weigh yourself first thing as soon as you get up,and use the bathroom as you will weigh your lightest in the morning.

He also said that the best time to exercise is 5 minutes after you get up and weigh yourself as you are burning calories from all different parts of your body and you are burning fat immediately. If you eat breakfast (or lunch, etc.) first and then exercise, you have to burn through what food you have eaten before you can burn fat.

The first bit's right, the second bit isn't.

The whole part of this website is to encourage people to realise that it's not about when you add or remove calories from your body, but it's about the net spend over a period of time. If you do 300kcals of exercise, it makes no difference if you do this first thing in the morning or last thing at night. You're right you're more likely to burn fat directly after a fast (you don't eat when you sleep) but this will limit your performance levels, and reduce your endurance. Athlete's will always train any time between meals, ensuring their blood sugar is high enough when they start exercising, and that they refuel after.

Someone interested in weightloss should worry less about immediate refuelling, but as I said initially, it is net calorie loss over a period of months which makes a difference, not making sure you're burning fat at the time of exercise.