There are a lot of different exercises you can do to help build lower body strength, but squats can be the most effective way to see the biggest changes in a short amount of time. The great thing about squats is that you don’t need any extra special equipment. It can help to have a wall or a chair nearby, but they aren’t a necessity.

Squats are great because they target so many different muscle groups in your thighs, calves, even your heels. Your core also gets quite a workout by doing squats, as you build muscles both in your back and your abdomen.

Here are some simple squats you can do at home, the beach, or the park after a run.

1) Basic squat –  Bend your knees and sink your bottom down towards the ground. Keep your feet shoulders distance apart, and make sure to keep your back erect. Don’t lean forward too much; try to keep up straight. Dip down as far as you can go. If you can reach a 90 degree angle, that is great. Don’t sink lower than that. Hold the squat for as long as you can. Stand up, shake your legs, and repeat.

2) Wall squats – Use a wall in your living room, a wooden post at the park, or the back of a bench. Squat down until your knees are at a 90 degree angle and rest your back against the wall, post or bench. You should be able to hold this squat for a longer period of time. Aim for 60 seconds. If you manage that, aim for 90. Stand up, and repeat.

3) Single leg squats – Hold on with your arm to a bench or chair. Stand on one leg and allow yourself to sink slowly towards the ground while maintaining your balance. Go as low as you can, but not more than 90 degrees. Hold squat for as long as you can, then rise and repeat on the other leg. You can hold your other leg in front of you, you can bend it in and rest it against the squatting leg, or you can hold your foot in your free hand behind you. Find what feels most comfortable.

4) Yogic squats – A great way to finish up, get a good stretch, and continue to build strength, yogic squats are deep squats. Stand up with your legs hip distance apart. Sink down as deeply as you can go, until your bottom almost touches the ground. Breathe deeply and focus on holding the position for as long as you can. If you cannot get all the way down, go as far as you can.