When it comes to working out, variety is key to success

PHILADELPHIA (WPVI) -- They say variety is the spice of life. It's also the key to success when getting in shape.

Because if you do the same workout everyday, chances are you'll get bored, you'll stop seeing results and you could face an injury.

Action News spoke with Billy Kirby - lawyer by day, certified fitness instructor by night - about the best ways to mix it up.

At Philadelphia Sports Clubs, Registered Nurse Ali Gorman tried his kickboxing class, modeled after the R.I.P.P.E.D program.

He also teaches spinning, strength training, and is getting certified in yoga.

"In changing up what you're doing, it keeps it exciting, keeps it energetic and better for your body," said Kirby.

Better for your body because by doing different workouts it shocks your muscles, which will lead to change, meaning results.

If you keep doing the same thing, your body gets used it, you'll hit a plateau and, "you're moving your joint in the same manner over and over and over again. That can cause injuries," said Kirby.

So for optimal fitness, Kirby recommends three things:

#1: High Intensity Interval Cardio: You're heart rate is up for several minutes. Then slow it down. Then back up again.

#2: Resistance or Strength Training: It's vital to build and tone muscle, and protect your bones.

#3: Yoga or Stretching: Something to help your body recover.

"Your body doesn't actually build muscle when you are working out. It builds muscle when you are resting, so you need that restorative time," said Kirby.