Turning down the music at your fitness classes won't affect the intensity of your workout, researchers say.

It's common for fitness instructors to crank up the volume -- sometimes to levels loud enough to damage hearing -- because they think it will help students work harder.

But researchers at the University of Maryland School of Medicine found there's no link between music volume ...

Sometimes, it's just not possible to fit in a workout in the morning or afternoon. But if you hit the gym in the evening, will you be up half the night?

New research says no. The Australian study found that 30 minutes of high-intensity interval training didn't have any negative impact on sleep.

In other good news, the researchers said the exercise session also seemed to que...