Travelle Gaines is the personal trainer for many professional athletes, but he has some practical advise for those who will be starting to work out for the first time.

"Any time you step into any gym, it can be intimidating for the first time," Gaines says. "So I think the biggest thing to do is just to focus. Understand why you're there. You're obviously there for a reason, to change your body, to change your mindset. So just start off slow. Put your headphones on. Get into your own groove. Don't worry about what everybody else is doing."

Here are some more tips from Gaines and his colleagues:

More Fitness Tips: Keeping Your Workout Fresh