CrossFit is a wildly popular approach to what some consider extreme fitness. It mixes exercise and dietary changes in order to build strength and/or lose weight. The workout can be modified depending on your fitness level and goals.

There’s also a CrossFit culture. Since the classes typically take place at a CrossFit gym, known as a “box,” people who train at the same box often develop a sense of community. They also use CrossFit language. For example, WOD stands for workout of the day.

Because CrossFit moves can be modified to fit nearly any fitness level, it’s said to be appropriate for just about everyone — young and old, fit and not so fit. But when starting with CrossFit, the best advice is to start slowly and work your way up.

We asked four CrossFit coaches and professionals for their input on the best moves for beginners. This is what we learned.

Todd Nief, owner of South Loop Strength & Conditioning in downtown Chicago, says you should begin the air squat by initiating the movement at both the hip and knees simultaneously, making sure your feet are flat on the ground throughout.

  1. Keep a neutral, braced position in the spine, tightening your core and watching out for arching or rounding of the back.
  2. Lower your body by bending at the knees and hips, tracking knees in line with your toes.
  3. Drop your hips below the knees.
  4. Push back up through your heels to a standing position.

The shoulder press is a fundamental beginner move, according to Jessica Murden, owner of CrossFit ACT in Saddle Brook, New Jersey, as it creates a “strong overhead position” for many of the more advanced CrossFit moves.

  1. Hold an empty barbell on the shoulders with a grip just slightly wider than shoulder width.
  2. Press the bar up, directly overhead.
  3. Return to the start position.

Burpees are the move everyone loves to hate. But why? They’re tough and effective, and Murden says they’re great for metabolic conditioning.

  1. From a standing position, lower yourself to a squat.
  2. Place your hands on the ground and kick your legs back into a pushup position.
  3. Do a pushup.
  4. Bring legs back into a squat position.
  5. From squatting, jump into the air, landing back in a squat position, and start again.

Brandon Mancine, personal trainer and CrossFit coach, warns not to use your knees if you can’t do a basic pushup. Resorting to your knees doesn’t allow you to build up the strength needed to eventually do a full pushup. Instead, he says, use a platform or something to raise your hands off the ground, which requires less strength.

  1. Place your hands directly under your shoulders.
  2. Lower yourself all the way to the floor.
  3. When you reach the bottom, immediately push up to starting position.

Need some help with your pushup form? Nief says releasing your hands, as in this move, will help you go all the way down — getting the most out of your pushups.

  1. Get into a pushup position.
  2. As you lower yourself, while the chest is in contact with the floor, release your hands momentarily.
  3. Place hands back on the floor and push up to a starting position.

The box jump is “one of the purest forms of explosive exercise,” says 2008 CrossFit Games champion Jason Khalipa.

  1. Using a stable box or platform, stand upright with your heels shoulder-width apart and toes pointing slightly outward.
  2. Begin to move downward into a squat, knees tracking over your feet.
  3. When you reach the bottom, propel yourself upwards, using your arms for momentum.
  4. Land with both feet simultaneously on the box, either in a standing or squatting position.
  5. Step or hop off.

To avoid injury, Khalipa suggests using an empty bar when you’re just starting out. If that’s too heavy, try a broom instead.

  1. Start with your feet hip-width apart. Throughout the exercise, make sure to keep your weight in your heels and your chest open.
  2. Squat down and hold the bar in your hands just slightly in front of your shins, directly above your feet. Your arms should be locked with your elbows facing outwards. Keep your chest as upright as possible.
  3. Begin to raise the bar vertically, pulling it slightly toward your body.
  4. Once the bar passes your knees, jump slightly and shrug to bring the bar as high as you can to catch it.
  5. As the bar reaches maximum height, squat under it by placing it in a front squat position, resting on the front of your shoulders. Repeat.

When you do a kettlebell swing, make sure to keep your knees unlocked and avoid driving them forward, says Nief. You will need a kettlebell.

  1. With your feet hip-width apart, back straight, and chest up, stand over the kettlebell.
  2. Squat down, knees tracking over feet, and grab the kettlebell with palms facing towards your body.
  3. Move into a standing position. As you do this, shift your weight into your heels, bending your knees slightly while pushing your butt towards the wall behind you.
  4. As you do this, swing the kettlebell through, between your legs.
  5. In a continuous movement, swing the kettlebell forward, raising it to just below shoulder height in front of you, contracting your glutes and hamstrings.

CrossFit can be a fun way to switch up an existing workout routine or kickstart new healthy habits. But be sure to listen to your body and modify the workout to meet your needs.

Whenever you’re new to a workout program, start slowly. Use small weights or no weights until you’re confident that your form is good. Build your strength slowly, and you’ll get more out of your workouts with less chance of injury.