Yep, it's a pretty short circuit (no pun intended) - just three exercises. That might make it seem easy, but don't get cocky. Each of these movements has the potential to completely trash your quads, especially if you crank up the intensity.
Start with the pause squat, move on to the step ups, then finish with the forward and reverse lunge combo. Take a rest when you're done with one set of all three exercises, then repeat the circuit two more times.
1. Pause Squat
Do these with a barbell, as shown in the video, if you're comfortable with it. If not, you can switch to a pair of dumbbells or kettlebells.
Get down to at least parallel, pause for 1-3 seconds, then explode up. Don't rush the pause - longer isn't necessarily better, but it'll kick your butt!
2. Step Up
8-10 reps per side
Beginners can do these with bodyweight only or a pair of dumbbells, while more advanced lifters might want to try using a barbell.
Make sure you don't push too hard off your back leg. Ideally, your forward leg should be doing all of the work.
3. Forward Lunge + Reverse Lunge
5 reps per side
Count each rep as one forward lunge plus one reverse lunge, so you're actually doing 20 total reps per set.
You can use dumbbells, kettlebells, or a barbell. Or, if you're in a bodyweight mood, just double the reps.