I'm Emily Jones, and I'm going to demonstrate the exertion of your quadriceps. Exertion of your quadriceps is any kind of activity that activates any muscles of the four major muscles of your quadriceps, hence quad, that means four. So I'm going to show you and demonstrate some exercises that will exert the energy of your quadriceps. There are multiple exercises that exert your quadriceps like squats, leg press, lunges, but I'm going to show you some extensions that will isolate your quadriceps. So this is the machine that you'll go to if you are at the gym. It's called the extension machine. You're going to have a seat, put your legs under the padded bar, make sure that your back is straight and you are comfortable. You're going to put it on a weight that puts enough resistance on your quadriceps but not too much resistance on your knees. You're going to kick up and hold, come back down. Make sure that you lower slowly keeping resistance on your quadriceps and isolating that muscle. You're going to continue the exercise about 15 reps pausing at the top. After you've done 15, you can rest for about a minute and continue for three sets.