Gretchen will walk you through an upper body crusher. It is 20 minutes of non stop effort. Make sure you have medium to heavy weights.

This tricep and cardio challenge will have you breathing heavy while your arms are shaking. A nice and quick smack down with Gretchen.

Your butt has nowhere to run in this workout. With nothing but your body weight, you'll be lunging, curtsey pulsing, squat walking, and burning in the first 5 minutes. It will burn, but more importantly, it will work.

A chest burnout without any push ups. Throw in heavy weights to help build strength and muscles.

What isn't this challenge? Legs, shoulders, cardio. The best of all the worlds collide in this 20 minute crusher! You need a loop band and a heavy set up weights.

You will target your glutes and hamstrings in this 20 minute challenge. Grab heavy weights as these are some of your largest muscles... they need it!

By only using the short band you will burn out your backside and probably curse out loud more than once during this 20 minute challenge.

This is a band challenge for your lower body. A mix between cardio and strength that will absolutely crush you.

You will use light weights or no equipment to one your back. This is a great compliment to the heavy lifting you may do in the other classes for your back. It is shocking how challenging laying on the mat can be.

A squat challenge designed to burn out your glutes so intensely you will have trouble sitting down. Don't miss this booty workout.

With the help of an optional loop band, this challenge will guide you through core dominated exercises. The perfect add on to a cardio or heavy strength day.

Get ready to burn out your legs with this challenge. All it takes is 20 minutes and a set of weights. If you want to strengthen and tone your legs, this workout is for you.

Find out why Gretchen shows up daily and what she wants to show her boys.