Experts say working out in the morning on an empty stomach is the best way to burn stored fat, making it ideal for weight-loss.
A morning sweat may also lead to better mental health and productivity throughout the day.
If you can swing a lunch time workout, that's the next best option.
By then you have eaten a meal or two and will have a performance boost.
It's also a good way to avoid the end-of-day slump.
If you're a night owl, night time workouts can help you wind-down from a stressful day.
You'll also workout longer because you're not pressed for time, and it can help you sleep better.