How to Train Your Hamstrings: RDLs, Leg Curls & Home Variations

The hamstrings are the muscles running down the back of your thighs.

And I'll be honest.

I've always had a bit of a love-hate relationship with them.

On one hand, properly developed hamstrings make a massive difference to how your legs look. You can have big quads, but when you've got thick hamstrings sitting behind them as well, your legs suddenly look considerably bigger from the side and the back.

They give the whole leg depth.

But there's another side to it.

You don't really see your own hamstrings.

I can stand in front of a mirror and see my quads. I can see them working. I can see the separation.

Hamstrings?

Not really.

And if I'm completely honest, hamstring curls have never been the exercise I've walked into the gym excited to do.

That's probably why I've traditionally left them until near the end of leg day, and it's probably also why my quads have always been considerably more developed than my hamstrings.

My legs aren't small. But if I'm looking at them critically, my hamstrings don't have the same level of clear development that my quads do.

That's something I'm trying to improve.

And it's one of the reasons I wanted to actually break down how I train hamstrings rather than just saying:

Do some leg curls.

Because there's more to it than that.

Your Hamstrings Aren't Just There to Look Good

Hamstrings are involved in basic movement all the time.

Walking.

Running.

Standing.

Getting up and down.

Moving the leg behind you.

Controlling the leg as it travels forwards.

The hamstring group contributes to hip extension and knee flexion, while also helping dynamically stabilise the knee during movement. Anatomy references describe the hamstrings as a group involved in both hip and knee function.

The easiest way I've always pictured them is almost like a spring-loaded system running down the back of the leg.

They're obviously not literally springs.

But as an analogy, it makes sense to me.

You lengthen the muscle. You put it under tension. Then you're asking it to produce force as you come back out of that position.

You'll see exactly what I mean when we get onto RDLs.

The Two Hamstring Movements You Need to Understand

For training purposes, there are two main hamstring movements I want you to understand:

Hip extension.

And:

Knee flexion.

Don't overcomplicate the terminology.

In basic gym terms, I think of it like this:

One movement works the hamstrings through the hip.

The other curls the leg through the knee.

Most of the hamstring muscles cross both the hip and the knee, which is why they contribute to both movements. The short head of the biceps femoris is slightly different because it only crosses the knee.

That's also one of the reasons I like using more than one type of hamstring exercise.

RDLs — Loading the Hamstrings in the Stretch

Take the Romanian deadlift.

This is probably the easiest movement for explaining what I mean by that spring-loaded feeling.

You've got the bar in your hands.

You start pushing your hips backwards.

And as the hips travel back, you begin feeling that stretch running down the backs of your legs.

That's the bit I'm looking for.

Your hamstrings are being put into a lengthened position under load.

This is what I mean when I describe them as feeling spring loaded.

Imagine pulling a spring apart.

You load it.

Then it wants to return towards where it started.

Again, your hamstrings aren't literally operating like a metal spring, but that's how I visualise the movement.

I push my hips back.

I feel the hamstrings stretch.

Then I drive the hips forwards and come back to standing.

Load them.

Then:

Drive back out of that loaded position.

That's the movement.

And one thing I really don't care about with an RDL is getting the bar as close to the floor as physically possible.

That's not the target.

I'm trying to push my hips backwards while maintaining control and tension through the backs of my legs.

If I've reached the point where my hamstrings are properly loaded and I can't push the hips back any further without changing the movement, that's enough depth for me.

I don't suddenly turn it into something else just because I want the bar another six inches lower.

The objective isn't:

How low can I get the bar?

It's:

Can I feel and control the hamstrings through the movement?

If you want the full breakdown of that movement, I've already written Romanian Deadlift — How I Train My Hamstrings.

RDLs and Hamstring Curls Feel Completely Different

I personally think of RDLs as training the hamstrings through that long, stretched position.

Then you've got the other side:

Knee flexion.

That's where the traditional hamstring curl comes in.

A lot of people, particularly people who don't do much compound hip-hinge work, hear “hamstrings” and immediately think of the hamstring curl machine.

And there's nothing wrong with that.

I use them as well.

How I Do Hamstring Curls

You've normally got two common versions.

Seated.

Or lying down.

You position yourself in the machine, lock your legs against the pads and then curl your lower legs back towards you.

Simple.

Bring your heels back.

Squeeze the hamstrings.

Then slowly control the weight as you return your legs towards the starting position.

I don't want to throw it backwards and then let the machine slam the weight back down.

I'm thinking:

Curl.

Squeeze.

Control it back.

That's completely different to the feeling I get from an RDL.

The Way I Picture It

I've always pictured it like this.

The RDL feels to me like I'm developing the hamstring through its length.

The curl feels more like I'm contracting and bunching the muscle up.

Almost like I'm trying to create a peak in the hamstring.

Now, that's how I visualise the exercise.

It's not literally how hamstring anatomy works.

You can't choose an exercise and somehow carve one isolated “peak” into the back of your leg.

But the visualisation helps me understand the difference between the movements.

One is predominantly a hip-hinge movement.

The other is direct knee flexion.

And I think there's value in having both.

Rather than asking:

Which one is better?

I'd rather ask:

Why would I leave one of the main functions of the hamstrings completely untrained?

Seated vs Lying Hamstring Curls

I've used both.

But there is an interesting difference between them.

When you're performing a seated curl, your hips are flexed, meaning several of the hamstring muscles start the movement at a longer muscle length than they do in a prone or lying curl.

A 12-week study comparing seated and prone leg curls found greater increases in overall hamstring muscle volume from the seated version in the participants studied. That doesn't mean lying curls are useless, but it does support the idea that training the hamstrings at longer muscle lengths can matter. Read the study on PubMed.

That doesn't suddenly make lying hamstring curls pointless.

They clearly work.

But it does reinforce something I pay much more attention to now:

Training muscles through controlled, lengthened positions matters.

My Garage Dumbbell Hamstring Curl

Then there's another variation I really like.

And I actually found this one when I was training in my garage.

Because believe me:

When your equipment is limited, you get creative.

I didn't have a proper hamstring curl machine.

I did have a bench.

And I had dumbbells.

So this became my alternative.

Lie face down on a flat bench.

I position myself so my knees are around the end of the bench and my lower legs can move freely.

Then I get a second person to carefully place a dumbbell between my feet.

And this part matters:

Make sure that dumbbell is secure before you move.

Once I've got it properly held between my feet, I curl my legs upwards.

I bring the dumbbell towards my backside.

At the top, I squeeze the hamstrings.

Then I slowly control it back down.

Again:

Curl it up.

Squeeze.

Control it down.

It's basically my homemade version of a lying hamstring curl.

Don't Try to Go Ridiculously Heavy

There's something I specifically want to point out with this variation.

I don't load this exercise heavily.

And I wouldn't recommend trying to.

You've got a dumbbell being physically held between your feet, the leverage changes as your lower legs move, and you've got nothing attaching that dumbbell to you.

So if your feet slip, the dumbbell can fall.

This isn't where I'm interested in proving how strong I am.

I use a weight that feels comfortable.

Something I can securely hold.

Something I can control through the full movement.

And something that lets me actually feel the hamstrings contracting.

If I'm spending more effort trying not to drop the dumbbell than I am training my hamstrings, I've gone too heavy.

Simple as that.

If you don't have somebody who can safely position the dumbbell for you, or you can't keep it completely secure, use another variation instead.

There is absolutely no reason to turn a homemade accessory exercise into an injury waiting to happen.

Why I Still Like the Dumbbell Version

I still really like it.

Partly because it reminds me of training in the garage and making the equipment I had work.

But it also forces me to slow down.

I'm not chasing a huge number on the machine stack.

I'm thinking about the movement.

I'm bending the knee.

I'm squeezing the hamstring.

And I'm controlling the lowering portion.

Sometimes limited equipment makes you think much harder about what you're actually trying to make the muscle do.

That same idea comes up in my article on mind-to-muscle connection: the point isn't just moving a weight from A to B. It's understanding what you're trying to make the muscle do.

So How Would I Actually Train Hamstrings?

If I'm trying to properly cover my hamstrings now, I don't want to simply throw three lazy sets of curls onto the end of leg day.

Which, admittedly, I've done plenty of times.

I'd rather include both movement patterns.

A hip-hinge movement.

RDLs would be my obvious choice.

Then:

A knee-flexion movement.

Seated hamstring curls, lying hamstring curls or another controlled curl variation.

That gives me the loaded stretch and hip-extension side.

Then it gives me direct knee flexion as well.

You don't need twenty different exercises.

You need to understand what the muscle actually does and choose exercises that let you train those movements properly.

If muscle growth is the wider goal, my complete beginner's guide to building muscle explains how resistance training, progressive overload, food and recovery all fit together.

The Biggest Hamstring Mistake I've Made

For me personally, the biggest mistake has probably just been not giving them the same attention as my quads.

I enjoy squatting.

I enjoy heavy leg movements.

I can see my quads in the mirror.

So naturally I've always been more motivated to train them.

Hamstring curls sitting at the end of leg day?

Much easier to neglect.

But when you look at a properly developed pair of legs from the side, you realise how much difference the back of the thigh actually makes.

Big quads with nothing behind them can make the leg look unfinished.

That's why I'm paying considerably more attention to them now.

Not just for size either.

They're part of basic lower-body movement, and if I'm going to train my legs properly, I don't want to keep treating the hamstrings as an afterthought.

What I'd Take From This

If you remember nothing else from this article, remember two movements:

Hip extension.

Knee flexion.

Think:

RDL.

And:

Hamstring curl.

One loads the hamstrings heavily through the hip hinge and gives me that stretched, spring-loaded feeling.

The other lets me directly bend the knee and contract the hamstrings through a completely different movement.

You can use barbells.

Machines.

Dumbbells.

Or, if you're training in a garage with limited equipment like I was, you can sometimes get a little creative.

But don't make exercises complicated just for the sake of it.

Feel the muscle.

Control the weight.

Progress it over time.

And maybe don't leave hamstrings until the last five minutes of every leg session like I did for years.

Your legs will probably thank you for it.

References

StatPearls: Hamstring Injury / Hamstring anatomy and function

Maeo S, et al. Greater Hamstrings Muscle Hypertrophy but Similar Damage Protection after Training at Long versus Short Muscle Lengths. Scandinavian Journal of Medicine & Science in Sports.