We always say "never skip leg day" because training the large muscle groups in your lower body helps you build a solid foundation so you can crush workouts and daily life like a queen.

When you select exercises to strengthen and tone your thighs, there are actually three different muscle groups you want to focus on: your quads (which run across the front of your upper leg and consist of four individual muscles), your hamstrings (which cover the back of your upper leg and involve three muscles), and your adductors (a.k.a. inner thighs).

That said, there are a handful of classic moves that do a fabulous job of challenging all of these muscles. We know, we know: There are a million different crazy moves being touted as must-do's all over Instagram, but don't underestimate the power of your basic squats, hip hinges, and single-leg movements. Below are the best thigh exercises to add to your leg day workout. Read on:

Banded lateral step-out squat

Muscles worked: glutes, quads

Why it rocks: This banded move fires up your glute medius muscles (a.k.a. side butt) and the outsides of your quads.

How to: Start standing with a resistance band wrapped just below knees, feet under hips, and hands clasped in front of chest. Take a big step to the right, then bend knees, sit back, and lower until thighs are parallel with the floor. Engage glutes and press back up through heels to starting position. Repeat on the other side. That's one rep. Complete two sets of 10 reps, resting as needed between sets.

Goblet squat

Muscles worked: quads, glutes, hamstrings

Why it rocks: Because of its countless performance (and everyday) benefits, the squat is one of the most important functional compound exercises everyone should master.

How to: Start standing with feet hip-width apart, holding a weight in front of chest, elbows pointing toward the floor. Push hips back and bend knees to lower into a squat. Press back up to start. That's one rep. Complete three sets of six to 10 reps, resting as needed between sets.

Dumbbell Bulgarian split squat

Muscles worked: quads, glutes, hamstrings

Why it rocks: This unilateral (a.k.a. single-side) movement helps improve muscle imbalances, overall stability, and single-leg strength. Talk about a triple-whammy.

How to: Start standing about two feet in front of a step, holding a weight in each hand. Extend left leg back and place ball of left foot on step. Bend knees to lower body as far as you can (or until knee hovers right above the ground), keeping shoulders back and chest up. Pause, then press through right heel to return to start. That's one rep. Complete three sets of eight to 12 reps on each side, resting as needed between sets.

Sumo deadlift

Muscles worked: glutes, hamstrings, adductors

Why it rocks: This is a popular variation of the conventional deadlift because the wider stance and foot placement target the glutes and inner thighs.

How to: Holding two kettlebells or dumbbells, start standing with feet slightly wider than hip-width apart, toes pointed out. Position weights in front of thighs, palms facing in. Keeping knees slightly bent, press hips back as you hinge at the waist and lower the weights toward the floor. Squeeze glutes to return to standing. That's one rep. Complete three sets of six to 10 reps, resting as needed between sets.

Kettleball swing

Muscles worked: glutes, hamstrings

Why it rocks: The KB swing is a low-impact, calorie-torching full-body movement that hits your glutes and hamstrings hard.

How to: Start in a hinge (hips back, knees slightly bent, torso leaned forward at 45 degrees) holding the handle of a kettlebell with both hands, arms extended straight toward floor and weight between knees on the floor. In one motion, squeeze glutes, straighten legs, lift torso, and thrust hips forward, while swinging the weight to chest height, keeping arms straight and core tight. Reverse the movement, bringing the kettlebell between thighs this time when you hinge. That's one rep. Continue for 30 seconds, then rest for 30 seconds. Repeat for four rounds total.

Step-up

Muscles worked: glutes, quads

Why it rocks: This move works your single-leg strength, balance, and stability at once.

How to: Start standing facing a box or other sturdy, elevated surface with hands on hips. Engage core, then step left foot up onto surface. Press through left foot to re-straighten left leg while driving right knee forward in front of body and up to hip height, maintaining a 90-degree bend in right knee and coming to balance on left leg on top of box. Return to starting position. Continue for 30 seconds, then rest for 30 seconds. Repeat for four rounds total.