The first time I truly felt my hamstrings work, it was on a seated leg curl machine at the end of a brutal leg day. My quads were spent. My glutes were done. But those hamstrings? They had just started.
We’ve all been there. Squats, lunges, leg presses — they hammer the quads whether you like it or not. The hamstrings rarely get that same automatic volume. Unless you’re deliberately adding in leg curls and hip hinges, they end up as an afterthought.
Here’s what the research actually says about building them.
The Why: Two Joints, Two Movements
The hamstrings have four heads. All of them flex the knee — like a leg curl does. Three of them also extend the hip. The short head of the biceps femoris does not.
So good hamstring training needs two types of exercises: leg curls and hip hinges.
Squats and leg presses? They’re probably not great for hamstring growth. Recent studies compared the hip thrust to the barbell squat — neither grew the hamstrings much. Another study compared a squat to 90 degrees of knee flexion with one to 140 degrees — same result.
Why? The hamstrings are biarticular. When you extend your knees and hips at the same time, they pull in two directions. Your body recruits the glutes and adductor magnus instead. So compound movements that demand both knee extension and hip extension simultaneously don’t do much for hamstring growth.
The How: Hip Hinges vs. Leg Curls
To make hip hinges effective, keep the knees relatively fixed with minimal knee-extension demands.
Research shows something interesting about how different exercises target different heads:
- Hip hinges tend to bias the long head of the biceps femoris and the semimembranosus.
- Leg curls tend to bias the short head of the biceps femoris and the semitendinosus.
This isn’t just anatomy — it forms a real reason to include both types in your program.
Coach’s Math
The four heads. Two movement patterns. One complete hamstring strategy.
Picking the Best Leg Curl
If you had to pick one leg curl, make it the seated version.
A study by Maeo et al compared the seated and lying hamstring curl. The seated position flexes the hips, putting more stretch on the biarticular hamstrings. It led to greater growth of those muscles.
The follow-up study compared a forward-leaning seated leg curl with the Nordic hamstring curl. The Nordic curl emphasized resistance at the bottom of the movement — it gets harder as you go down. That produced greater short head and sartorius growth, while the seated curl produced greater long head and semimembranosus growth.
Bottom line: the seated leg curl is probably your best bet for overall hamstring growth. The lying curl helps the sartorius occasionally, and the Nordic curl is great for the short head.
The Takeaway
Hip hinges and leg curls together cover all four heads of the hamstrings. Hinges bias the long head and semimembranosus. Curls target the semitendinosus and short head. Among curl options, seated is most effective overall.
My notebook says: when I program hamstring work, I start with one hip hinge (stiff-legged deadlift or Romanian deadlift) and one seated leg curl. That’s the foundation. Then I add Nordics if short-head strength matters — like for injury prevention.
Your Move:
Step 1. Add a seated leg curl to your next leg session — just 3 sets of 8 reps is enough to start.
Step 2. Swap one squat-heavy day for a hip hinge. A stiff-legged deadlift works perfectly here.
Step 3. Notice the difference in how your hamstrings feel two days later. That burn you didn’t expect? That’s what happens when they finally get the work they deserve.