In this series, we take common beauty questions, of which we’ve heard about 23,464 conflicting answers to over the years, and myth-bust ‘em once and for all.

Workout Night - LEAD
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If you have a 9-5, you probably check into the gym early in the AM or you hit up the treadmill on your way home from work. Everyone has their preference on when they exercise, but does one yield better results for your body? Does the early bird get the worm and a more effective workout, or is the night owl scorching more calories?

Before you set your alarm for the break of dawn or change your auto-enroll, it might all depend on how your body functions.

"The most critical aspect to consider the best workout for any given individual is their circadian rhythm which is a 24-hour cycle controlling all the physiological processes of humans," says Alex Zimmerman, the Director of Tier X Training at Equinox. "Our circadian rhythm can include organization of sleep/wake patterns, hormones and metabolism, and even athletic performance."

He says that someone that goes to work at 10 AM will have a very different clock than someone who starts work at 10 PM, so that difference in their sleep/wake cycle will effect how and when they workout—and how they feel during the exercise session.

"Our wakefulness and sleepiness is dependent on our sleep/wake cycle. What's most important is that we find a way to maximize this sleep cycle and establish consistent sleep and wake times, which can have implications on our ability to build muscle, lose body fat, think clearly, mitigate the risk for disease, and have the energy to work out," says Zimmerman.

He says there is some evidence that hormone cycles could allow for increased performance and coordination 10 hours into your wake cycle, but it's not very strong or conclusive.

So how do you figure out the best time to workout? First, take a look at your schedule (i.e. when you have the 30 mins to actually head to the gym) and pay attention to how you feel during the day.

"Workout whenever you can—just make sure that you actually do it," says Lily Miesmer, a SoulCycle instructor in New York City. It's about finding the time that works for you and sticking to it. If you feel more awake after a full day, workout in the evening. If you know you'll never go after work, it's best to make time in the morning."

Many gyms open their doors around 5 AM and shut down close to or even after 10, while SoulCycle now offers class as early as 5:30 AM and as late as 8:20 PM.

However, Zimmerman says you should make it as easy for yourself as possible. For example, consider packing a bag the night before and hitting the hay early if you want to log in a few miles before work.

"A routine that someone can stick to is going to outweigh any hormonal, physiological advantage that the body may present as it relates to working out!"