Do squats. Don’t be a cry baby. Squats suck. Everyone hates them because they put so much stress on your body. Only crazy people love squats. Get over it. Nothing else comes close to building your leg size and strength. Squats are also highly beneficial to your knees and back. Keeping your bones and joints strong means regular stress, like the kind that comes from squats.
Grab a squat rack. Set the hooks at the top of your chest. Set the safety bars just below your hip socket. If for whatever reason you go down and can’t get back up, you can roll the bar off your back and the bars will catch it.
With the bar in the hooks, you should have to bend down a little to get under the bar and get it on your shoulders. As you’re getting the bar on your shoulders, pinch your shoulder blades back tight and let the bar roll onto your flexed traps. Before you lift the bar, put your hands on it as close to your shoulders as comfortable. This will help lock your shoulders into position. The goal is to keep your back flexed backwards. If you let your back roll forward, you risk injury.
Extend your legs and straighten your hips to lift the bar. Take a step back and position your feet just outside your shoulders, pointing out. Visualize the squat. See yourself going all the way down with a tight back, bottoming out on your hamstrings and driving the weight up, chest up, heels through the floor. Now execute.
Be sure to stretch before and after doing squats. I’ve noticed that failure to do so will lead to a big reduction in flexibility, increasing the risk of injury. Also make sure to properly warm up with 2-3 lighter sets before you build up to your working weight.