Lunges are a quintessential exercise; you can do them anywhere and the effects can be seen in no time, in the form of shapely, toned legs and backside (just in time for bikini season!). If you’re planning on incorporating lunges into your routine, however, make sure you’re not doing more harm than good. Find out how to do lunges correctly below.

The basics: It’s important to do lunges properly so you don’t put unwanted strain on your joints. Here’s how to perfect your form:

  • Keep your upper body straight, with your shoulders back and relaxed and chin up (pick a point to stare at in front of you so you don’t keep looking down). Always engage your core.
  • Step forward with one leg, lowering your hips until both knees are bent at about a 90-degree angle. Make sure your front knee is directly above your ankle, not pushed out too far, and make sure your other knee doesn’t touch the floor. Keep the weight in your heels as you push back up to the starting position.

Challenge your muscles: Now that you have the basics down, you can modify your lunge workouts in many different ways in order to work different muscles. For example, Crunch gym personal training manager Tim Rich recommends reverse lunges (stepping back instead of forward) as a good way to complement the forward movements in your daily life. “We always move forward,” Tim says. “Moving in a reverse direction requires more skill and helps regain some balance and athleticism.” Here are more recommended lunge variations to try:

Injury prevention: Even though lunges are one of the best ways to work your lower body, some people tend to avoid lunges because it can put too much strain on the knees. If you feel pain, Tim recommends you take smaller steps as you lunge. “Reducing the range of motion will still develop good strength and alignment,” Tim says. Slowly increase your lunge distance as your pain gets better. Some people also find that doing a reverse lunge instead of a forward lunge also helps reduce knee strain.