The back of your thighs is made up of three muscles that work together as the hamstring group: the biceps femoris, semitendinosus, and semimembranosus. These muscles do two main jobs: they extend your hip (pushing your leg behind you) and flex your knee (bending your lower leg back). To fully develop the back of your thighs, you need exercises that challenge both of those movement patterns, not just one.
Why Both Movement Patterns Matter
Most people default to one type of hamstring exercise, usually a leg curl machine, and call it a day. But that only covers knee flexion. Research on muscle activation shows that different exercises light up different parts of the hamstring group. Hip extension movements (like deadlift variations) preferentially target the biceps femoris on the outer portion of your thigh. Knee flexion exercises (like leg curls and Nordic curls) drive more activity in the semitendinosus along the inner portion. A complete routine includes at least one exercise from each category.
Exercises performed in a lengthened position, where your hamstrings are stretched under load, also produce more muscle growth. A 12-week training study found that lengthened-state eccentric exercises increased overall hamstring muscle volume by 18%, compared to 11% for Nordic curls alone. Both are worth doing, but if you only pick one style, lengthened movements like Romanian deadlifts give you more size.
Best Gym Exercises for the Back of Your Thighs
Romanian Deadlift
The Romanian deadlift (RDL) is the single most effective hamstring builder for most people. You hold a barbell or dumbbells in front of your thighs, keep a slight bend in your knees throughout, and hinge forward at the hips until the weight reaches about shin level. The bar never touches the floor between reps. This shorter range of motion keeps constant tension on your hamstrings and glutes as a unit, and the slight knee bend makes it more forgiving on your lower back than a stiff-leg deadlift.
The stiff-leg deadlift is a close cousin. Your knees stay nearly locked, and the weight travels all the way to the floor. This version demands more hamstring flexibility and places greater stress on the lower back, so it’s better suited for experienced lifters who already have solid mobility. If you’re newer to training, the RDL is the smarter starting point.
Leg Curl Variations
Lying, seated, or standing leg curls isolate the knee-flexion function of your hamstrings. Research using high-density electromyography found that leg curls produced some of the highest hamstring activation levels, reaching 69% to 85% of maximum voluntary contraction during the lifting phase. If your gym has both a lying and seated curl machine, the seated version stretches the hamstrings more at the hip, giving you that lengthened-state training advantage.
Hip Extension Movements
Upright hip extension (think of a cable kickback or a reverse hyperextension) was the only exercise in activation studies that preferentially worked the biceps femoris over the inner hamstrings. Straight-knee glute bridges also ranked among the highest for overall hamstring activity, hitting 40% to 54% of max contraction even during the lowering phase. Including one dedicated hip extension exercise fills a gap that deadlifts and curls leave behind.
Bodyweight Options You Can Do at Home
You don’t need a gym to build the back of your thighs. These four movements cover both hip extension and knee flexion using nothing but your body weight and a floor.
- Nordic curls: Kneel on a pad and anchor your feet under a couch, heavy furniture, or have a partner hold your ankles. Slowly lower your torso toward the floor, controlling the descent as long as possible, then catch yourself with your hands and push back up. This exercise prioritizes the eccentric (lowering) phase, which is where hamstrings build the most strength and resilience. Start with 2 to 3 sets of 3 to 5 slow reps and build from there.
- Single-leg glute bridges: Lie on your back, plant one foot on the floor with your knee bent, and extend the other leg straight. Drive through your heel to lift your hips until your body forms a straight line from shoulder to knee. Lower with control. Aim for 2 to 3 sets of 12 to 15 reps per leg.
- Good mornings (bodyweight): Stand with your hands behind your head, keep a slight knee bend, and hinge forward at the hips until your torso is roughly parallel to the floor. You should feel a deep stretch in the back of your thighs at the bottom. Squeeze your hamstrings and glutes to stand back up. Perform 2 to 3 sets of 8 to 12 reps.
- Prone hamstring curls: Lie face down with your legs straight. Bend one knee and pull your heel toward your glutes, flexing your foot and driving it through space. Keep your hip and thigh pressed into the floor. Return slowly. This is a low-intensity option that works well as a warm-up or finisher. Aim for 2 to 3 sets of 12 to 15 reps per leg.
How Often and How Much
Training your hamstrings two to three times per week is a solid frequency for growth. In the 12-week hypertrophy study mentioned earlier, participants trained three sessions per week (with two sessions in the first and last weeks), starting at 2 sets per session and building to 4 sets, with reps progressing from 6 to 10. That gradual increase kept the muscles adapting without overloading joints and tendons early on.
A practical weekly target is 6 to 12 hard sets for your hamstrings, spread across two or three sessions. If you’re already doing heavy squats and conventional deadlifts, those contribute some hamstring work, so you can stay closer to the lower end. If your program is more upper-body focused, aim higher. Each session should ideally include one hip-extension exercise and one knee-flexion exercise to cover both functions.
Warming Up Your Hamstrings
Cold hamstrings are stiff hamstrings, and stiff hamstrings are injury-prone hamstrings. Tight hamstrings also alter how your lower back and pelvis move together during forward bending, which can increase stress on your lumbar discs over time. Five minutes of dynamic movement before your workout makes a real difference.
Effective warm-up drills include inchworms (walk your hands out to a plank, then walk your feet toward your hands), monster walks (exaggerated straight-leg steps forward), and Spiderman walks (deep lunges with a torso twist). These stretch the hamstrings through movement while also activating your core. Save static stretching for after your session.
Protecting Your Hamstrings From Injury
Hamstring strains are one of the most common lower-body injuries in sports, and they have a frustrating tendency to come back. The Nordic hamstring curl is the single most studied exercise for prevention. A meta-analysis of 8,459 athletes across 15 studies found that programs including Nordic curls cut hamstring injury rates by up to 51%, essentially halving the risk. This held true across multiple sports, age groups, and both men and women.
The protective effect comes from eccentric strength, your hamstring’s ability to control lengthening under force. This is exactly what happens when you sprint, decelerate, or kick. Even if muscle growth is your primary goal, adding a few sets of Nordic curls each week is worth the insurance.
One form mistake to watch for across all hamstring exercises: letting your lower back do the work. If your hamstrings are tight or weak, your lumbar spine tends to round excessively during hip hinges to compensate for the range of motion your hamstrings can’t provide. Focus on hinging from your hips, not your lower back. If you can’t keep your spine neutral during an RDL, shorten your range of motion until your flexibility improves.