We All Have really Weak Hamstrings

And That's Bad

by Alec Enkiri | 12/13/19


We've all got really weak hamstrings - and that's bad. Unfortunately, however, it's easy as an avid strength & performance trainee to kid yourself into thinking you don't have this problem. You might say:

But I can deadlift 500lbs for reps!


I can do Romanian deadlifts with over 400lbs! 


My good morning and my kettlebell swing and my weighted hyperextension are all leaps and bounds stronger than anyone else's that I've ever seen in person, so how on Earth could I possibly have weak hamstrings???

But I bet you do. Here's the thing, as guys who are only interested in becoming as big and strong as possible we always get so tied up in what our hips can do, and for good reason! The hamstring and glute complexes are two of the largest muscle groups in the body and two of the most important muscle groups when it comes to aesthetics, strength, and overall performance. And these muscles act primarily to extend the hips. So, we flex our hips over and over and over so we can extend them, under load, over and over and over under various different conditions to build those muscles into being as strong and explosive and powerful as possible. That's all fantastic.

But what we always forget, what is so easy to overlook because it does not necessarily carry over directly into performance or create tangible increases in performance that we can measure and see with ease, is that the hamstrings are a bi-articular muscle group. This means that they actually cross over 2 different joints - not just the hip, but also the knee. This means that the hamstrings do more than just perform hip extension. They are also responsible for knee flexion! Thus, if you are ignoring knee flexion movements and only training movements that hit the hamstrings via hip extension then you are ignoring a large component of the function of the muscle group, and therefore the muscle group cannot possibly become fully developed or optimized in terms of strength and force output capability.

Listen To The Bodybuilders

The ironic part here is that bodybuilders, who don't even care about performance but tend to have such a neurotic obsession with isolating every joint in the body individually, actually end up being sure to work both the hip extension function of the hamstrings as well as the knee flexion function of the hamstrings primarily through leg curls. Consequently, they actually end up working their hamstrings more fully than many strength and performance based athletes even though they don't actually need their hamstrings to be functionally capable of performing. Now that's irony!

Although, simple leg curls do leave a whole hell of a lot to be desired in terms of actually working the hammies in an ideal fashion, but doing leg curls at all is still better than ignoring the knee flexion aspect of the hamstrings altogether, which is what you tend to see with people who are more performance minded. This is again ironic because these are the sorts of people who are perfectly willing to work the hamstrings hard and heavy and consistently because they clearly see the value this work has in terms of performance enhancement, but that work still tends to be relegated to hip extension dominant patterns rather than knee flexion ones. This is likely because it's easy to see the boost in performance that occurs when you take your deadlift from, let's say, 300lbs up to 500lbs. Whether your goal is speed, power, size, strength, whatever. The benefit here is quite obvious. You simply become a more formidable athlete and human being in this case.

Everybody wanna be a bodybuilder, but ain't nobody wanna do their damn leg curls.

An Insidious Demon

However, the same obvious benefit doesn't really take place when you increase knee flexion strength, even if it's to a substantial degree. There's no obvious overall size increase; no boost in total body strength & power. So, you may ask, why bother at all then? And that's the conclusion many of us have come to, including myself for many years. But the problem is that there's a hidden and insidious demon furiously at work beneath the surface when you neglect your knee flexion strength. If you're an athlete, one day you'll take off into a sprint and the hamstring will go. Maybe just a little strain and then it'll "heal" after a few weeks. But then it'll go again; and then again; and then again; and then again! Until the day comes where the rehab just doesn't "stick" anymore. By then you'll be gun shy anyway. You'll be too scared to take off with full power because you'll always be thinking this could be the one - I'm going to bolt off here, the damn thing is just going to go completely, and that's going to be all she wrote - the last time you take off with any respectable explosive power whatsoever. Can't build explosive power and speed or compete in athletics of any kind if you can't take off unhinged or run at full capacity.

Pre-workout for lifters who ignore this article.

If you're a lifter, you'll probably notice that your knees start to hurt at some point. Shit, flexing them to work the hamstrings probably makes them hurt so you're definitely going to avoid that! Just a little ache at first. Put a little menthol on your knees after a hard day of training. Once it progresses you can rub a little bit of capsaicin in into your knee sleeves for that intra-session relief. After that stops being effective you can pop a couple ibuprofen before your squat days. Pretty soon you'll start needing it off days too though. Actually, you should probably start walking down the stairs backwards right now just to get used to it because that will be the only way that's going to be possible in a few years if you keep going down the current path. Ah, to be 35 and not be able to walk down the stairs.

See, the benefit is not immediately obvious here, rather, it becomes obvious later. It's pretty obvious to me now at 31, but it wasn't obvious to me when I was 21. Back then the logic was:

Well, if I squat more often and deadlift more often I get faster and stronger and bigger, and I can do so much faster than when I waste precious time and resources worrying about isolated functions like curling my leg up behind me.

Until the day comes where I can't because I've neglected something that is so integral for far too long and disproportionately developed the pieces around it that then push and pull and prod and yank on it at a level that it's not accustomed to handle until it's so irritated that it hurts like hell all the time or simply begins to lose function altogether. This is why the demon here is insidious. It becomes stronger over time. You're not necessarily doing anything wrong by focusing your hamstring training on hip extension patterns, but you are unwittingly neglecting something incredibly important by ignoring knee flexion patterns, and that neglect is the only fuel the demon needs to grow.

If your knees hurt all the time or you're always pulling your hamstring then you're going to have a hell of a difficult time putting in the work that you need to be able to put in in order to continue to make progress as you age. And if you're 20 right now and your knees hurt I can promise you they're only going to hurt more by the time you're 25, and even more than that by the time you're 30, unless you choose to fix the issue today.

This is pretty much all quad. Having strong knee flexion capabilities does absolutely nothing to improve this movement directly. Hard to train it when your knees hurt all the time though.

The King Of Knee Flexion Exercises

Personally, I've been lucky. I never pulled a hamstring badly or had a recurring strain that I could not shake. I have, however, witnessed a multi-year, recurring strain that made it pretty much impossible for the athlete to train properly and also completely killed his confidence in his speed and explosiveness. It sucks and I felt bad for him, but it's just the cost of doing business sometimes and I didn't know how to help him at the time, nor was it my job to do so. But this example highlighted to me at a young age just how debilitating and devastating a simple hamstring strain can become if it's not handled properly.

As for me, like I said, I've been lucky. My knees ache a little sometimes when I squat, but that's about it. Prior to implementing and, equally as importantly, scaling the exercise I'm about to show you, they also used to ache like hell whenever I would try to perform any type of intense knee flexion work, which led to me mostly avoiding it. By intense, I don't mean leg curls or any of that other stuff you see PT's prescribe on physio balls or anything like that. Those all have their place, but they fall short when it comes to really making the big gains in this regard. Here I'm referring to the king of knee flexion exercises, and that is the Nordic leg curl, also known as a natural glute ham raise ("glute ham raise" is actually a bit of a misnomer here in that the glutes are not actually dynamically involved in this movement at all as it is purely knee flexion).

Assisted negative Nordic curls. These are working sets. 5 reps, 3-5 seconds per negative, with 10lbs of assistance on the pulley.

This exercise is the King and the Emperor and the Lord and Savior all in one. If you can legitimately control even just the negative portion a few times, then you likely have sufficient knee flexion strength to keep the balance that is required here and both protect the knees and protect the hamstrings from themselves (in regard to the latter, it can even be argued that eccentric knee flexion strength is actually more important than concentric strength as the majority of hamstring pulls occur during the swing phase of the running gait as the knee is opening up, at which point the hamstring muscles are required to overcome tremendous eccentric forces to maintain control of the leg. Insufficient eccentric strength here then potentially leads to tears when the eccentric forces become larger than what the muscles have been conditioned to handle).

The problem with this exercise is that it's too difficult. Like I said a minute ago, they used to make my knees hurt. Badly. I couldn't even generate maximum tension in the hamstrings before when trying to do them because the tension required to maintain control was so high, so much higher than what I was capable of generating, that instead I would just kind of plop down to the ground and basically get nothing out of the exercise. It was so beyond me that I couldn't even make use of it. It still made my knees ache though. This is the same problem that most people have. The exercise is so advanced and most people's starting point is so far away from it that the gap between the two simply cannot be reconciled. You can get as strong as you want at leg curls, but in doing so you'll never build the strength to be able to do a proper Nordic curl. The movements are just not on the same level. In that same vein, you can do all the Nordic curl reps you want where you're basically just falling down to the floor like I was before, never generating maximum tension, and then catching yourself with your hands and pushing yourself back up. You'll never be able to bridge that gap this way though.

So then you might try adding a band to give you some assistance and make the reps more manageable. You can argue that the band works with the natural strength curve of the exercise; that as you drop yourself forward and the band stretches it adds more and more assistance to the movement when you need it most, as the mechanical advantage at the joint decreases. And this sounds good theory, but it doesn't pan out in the real world. The band version just never quite sits right. It doesn't really work. And I love bands! I've found many very valuable uses for them and I always make sure to keep a few different varieties on hand because of it, but this exercise isn't one of them. The band is either going to provide too much assistance and make it too easy or it's not going to do enough and it's still going to be too difficult. Not to mention, how do you progress anyway as you get stronger? You can't grade the bands and you can't scale them. You don't how much they're helping you and you don't know which one to switch to go up just one notch and slowly bridge your way across that gap. You can try, but it's not really practical and I don't see the point because there's a better way.

A Better Way

Enter the pulley. With a standard pulley system and a rope handle you can start performing the exercise from a starting point that is optimized to your current strength levels. Simply use the weights on the cable stack to provide assistance. The more weight on the stack, the higher the assistance; the less weight on the stack, the lower the assistance.

Kissing the floor with just 5lbs of assistance on the pulley. This is the type of control I'd like to be able to demonstrate during unassisted negatives.

You can then remove the assistance plate by plate over the course of several months until you're able to perform the movement unassisted. A maximum of 5 pound jumps seem to be ideal here, so if the plates on the stack are 10lbs each then you can cut that in half by holding a 5lbs plate to your chest before removing a plate on the stack. So for example, if you need 30lbs of assistance in week 1 then you will use 3 plates on the cable stack. When you want to drop down to 25lbs of assistance in week 2 then you will continue to use 3 plates on the cable stack but also hold a 5lbs plate to your chest. Then in week 3 when you want to go down to 20lbs of assistance you will just use 2 plates on the cable stack and not hold a plate to your chest. And so on and so forth until you get to a point where you can perform them unassisted.

Done this way and begun at a challenging but actually manageable level, I think you will find that this exercise has more value than it is generally credited with. When you're using "weights" you can actually handle here the tension you can generate in your hamstrings is going to be unlike anything you have ever felt there before. Contrast this with the way it's normally done, where the exercise is so far beyond most peoples' capabilities, as it was for me before, that the body simply shuts down the muscular contraction altogether before it comes to close to being meaningful.

This is a protective mechanism to prevent injury. That's why when you see people trying this exercise they get about a third of the way down and then they basically just free fall to the floor and catch themselves. The exercise is so far beyond them that their body won't even actually let them attempt it in earnest and so they get nothing out of it. But when you can scale it down and match it to your capabilities the tension you can generate in the hamstrings is insane and the improvement begins to take place rapidly, and that carries over and you can quickly begin to feel it in other things as well. Not to mention your knees will feel more solid and healthy overall, generating maximum knee flexion tension will no longer be achy or painful, and you'll be much less likely to tear a hamstring in half when your kid starts running toward a busy intersection and you have to go from 0-60 instantaneously to sprint over and grab hold of them before they get there.

First attempt at an unassisted negative after practicing assisted work for a few weeks. Not quite there yet, but it's a work in progress.


I recommend 3-4 sets of 5-8 reps done 1-2 times a week a week. Personally, I'm experimenting with negatives only right now as I believe that is where the bulk of the value lies with this exercise, and by putting all of your effort into the eccentric you can really hone in on that insane tension and learn how to keep it firing high and maintain control of your body even as fatigue sets in heavily. A worthy goal to strive for, in my opinion, would be 5+ negative reps, completely unassisted, and fully controlled (4-6 seconds from top to bottom). I want to be able to kiss the floor and keep all of my teeth. I'll report back when I've accomplished this.    

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