Love them or hate them, leg days aren’t the days to skip in the gym. They give the muscles in your lower half their time in the spotlight, rewarding you with greater muscular power, speed, and strength, which are all useful in sports and daily life. Need some leg day inspiration? Here, three personal trainers share the leg day moves they consider non-negotiable. Steal them for your next lower-body workout.

1. Bulgarian Split Squat

One brutal but worthy must-have: the Bulgarian split squat. The Bulgarian split squat zeroes in on the quads and glutes the way other squat variations do. However, it has a few added bonuses, according to Life Time personal trainer Lindsay Ogden, C.P.T. 

First, working one leg at a time enables you to sink deeper into the bottom position. Essentially, giving you the opportunity to improve your range of motion, Ogden says. That can help you work in greater ranges of motion in your other leg day exercises. 

The Bulgarian split squat is also a terrific move for building core strength and stability, Ogden notes. The split stance makes it harder to balance, which forces your core muscles to jump in to keep you from toppling over.  

Plus, the Bulgarian split squat tends to be friendlier to the back than other squat variations. It encourages a more upright torso, so there’s less forward lean and less potential stress on the lower back and hips, Ogden explains. 

2. Single-Leg Romanian Deadlift

The single-leg Romanian deadlift (RDL) made it on all three trainers’ lists of go-to leg day exercises.

“Single-leg exercises [like the RDL] place more emphasis on a stabilizing muscle known as the gluteus medius,” says athletic trainer Casey Lockwood, A.T.C., a presenter with Les Mills. The gluteus medius—or glute med for short—is your side-butt muscle, and it plays a key role in balance. 

Read More: 4 Deadlift Mistakes You Might Be Making—And How To Fix Them

The RDL also targets your gluteus maximus (the large muscle in your buttocks) and hamstrings. “Strong hamstrings and glutes are important for low back and knee health,” notes Albert Wiggins, C.P.T., personal training manager at Crunch Fitness.

For a maximum stability challenge, do this exercise with kettlebells or dumbbells. But if you really want to load your hamstrings and glutes, go for a barbell in the landmine attachment. “Landmines provide more balance so you can focus on pulling heavier weight without having to stabilize as much,” Ogden says.

3. Stability Ball Hamstring Curl

“This exercise is great because it incorporates balance and stability while giving an incredible burn in your hamstrings,” Wiggins says.

True, a machine hamstring curl will better emphasize your hamstrings for muscle growth. However, the stability ball hamstring curl gives you more bang for your buck. You see, performing this exercise on a stability ball requires your glute and core muscles to turn on in order to help you stabilize the ball throughout the movement, according to Wiggins. 

Wiggins also appreciates the accessibility of the stability ball hamstring curl. “It only requires a stability ball and your own body,” he says.

4. Hack Squat

If you’re lucky enough to work out in a gym with a hack squat machine, take advantage of it. A hack squat is an effective way to build strong, athletic-looking quads. 

The hack squat machine features a fixed platform that you stand on, and shoulder pads for loading weight. It’s also positioned at a 45-degree angle. This, along with the machine’s fixed path, places less demand on your joints and permits a deeper range of motion compared to the traditional back squat, Ogden says.  

Read More: Signs You Have Weak Glutes—And How To Strengthen Them

You may appreciate the greater range of motion if big quads are on your wish list. As Ogden explains, range of motion is a key contributor to muscle growth — the greater your range, the more muscle you recruit.  

And because the hack squat machine stabilizes your back, your leg muscles — the quads in particular — can do more work. More work equals greater gains.  

5. Reverse Lunge

The reverse lunge is another great single-leg exercise that targets the glutes, hamstrings, quads, and calves. 

Wiggins favors the reverse lunge because it consistently feels better on the knees than walking lunges. In a reverse lunge, your front foot stays in contact with the ground the entire time, allowing you to better control the placement of your knee over your ankle. “If your objective is less pain and more functionality, this is a great move for you,” Wiggins says. 

Plus, you can vary the reverse lunge by weighing it with cables, dumbbells, kettlebells, a barbell, or just your body weight.