So, you want to know the ideal leg extension to leg curl ratio?
I’m sure we can agree that these are two fantastic isolation movements for both your quads and your hamstrings.
However, should you be able to lift a certain amount of weight with one exercise in relation to the other?
Or are the main muscle groups in the legs so different that there’s no way to really compare the two?
Allow me to reveal all.
Leg Extension to Leg Curl Ratio
There’s no actual “ideal” leg extension to leg curl ratio. That being said, most people will find that their leg curl is approximately 50-85% of their leg extension. Many experts believe that your hamstrings should be 55-60% as strong as your quadriceps. Another way to look at it is that the quads have 4 muscles, whereas the hamstrings have three muscles. So, in an “ideal” world your leg extension to leg curl ratio would be 4:3, or your leg curl should be 75% of your leg extension. Personally, I feel this is closer to the optimum ratio.
1. Should Leg Extensions and Leg Curls Be the Same?
In a perfect world we would all have completely symmetrical bodies, in terms of both size and strength.
Therefore, you could say that your quads and hamstrings should be equal strength.
So, you should be able to perform leg curls with as much weight as you do leg extension.
But, let’s face facts, it’s not a perfect world, and this “equalness” between these two exercises rarely, if ever, occurs.
In truth, most of us have far stronger quads than hamstrings.
When you look at the anatomy of the leg, this actually makes quite a lot of sense.
The quads are made up of 4 separate muscles, whereas the hamstrings are 3 muscles.
So, you could almost look at this and say that the ideal leg extension to leg curl ratio is 4:3.
This is based on the number of muscles, but this again would be a perfect world scenario, which very rarely happens.
In reality, as I say, most people have far stronger quads than hamstrings.
And this typically comes down to how the muscles are used in everyday life, as well as in the gym.
RELATED===>Why Do Leg Extensions Burn So Bad?
I will touch on this in more detail in a moment, although it is extremely unlikely that anyone will be using the same weight for leg extensions and leg curls.
But, for now let’s have a look at some “real” stats and figures.
The “REAL” Leg Extension and Leg Curl Ratios
So, taking all of this into consideration, as I say, the vast majority of people will never have an equal leg extension and leg curl.
In truth, you can generally expect your leg curls to be anywhere between 50-85% of your leg extensions.
Now, I know that this is a huge range, but I’m willing to bet that a very high percentage of people will fall somewhere in-between.
In fact, if your percentages are significantly lower or higher than these, this points to a potential muscle imbalance.
And this is something that you need to be extremely wary of, as it may potentially lead to future injuries.
RELATED===>Why Do Leg Extensions Hurt My Knees?
That being said, many fitness experts state that your hamstring strength should be around 55-60% of your quad strength.
However, I don’t actually agree with this, and feel that the optimum strength percentage should be around 70%
Now, just to make this even more confusing, over at StrengthLevel it appears that the leg curls are approximately 82% of leg extensions for both average and elite lifters.
Just in case you weren’t aware, StrengthLevel is a community where people will record their various lifts.
So, there is a database built up of hundreds and thousands of people sharing their stats with just about every exercise you can think of.
2. Factors That Affect Leg Extension to Leg Curl Ratio
We can actually see our quads, but with the hamstrings being behind us, we very rarely know exactly what they look like.
And unfortunately, this is often how some people train in the gym.
The muscles that are more visible to THEM are the ones that get trained more often.
If you don’t believe me then explain why bench press and bicep curls are two of the most, if not THE most, popular exercises in the gym?
How about an example for two muscles that aren’t in your legs to “prove” this point.
The triceps take up approximately 60% of your upper arm area, whereas the biceps take up the remaining 40%.
The triceps have 3 heads, the biceps have 2.
And yet, which of these two muscle groups typically gets more attention?
RELATED===>Bicep Curl to Tricep Extension Ratio
You know for a fact that it’s the biceps, and simply again because they are the muscle on the front of the body, which is more visible.
So, back to the leg extension to leg curl ratio, if you’re not falling into the 50-85% strength ratio range, or if you’re much closer to one end of the scale than the other, this points to a potential muscle imbalance.
It is also likely that you are training one muscle much more than the other.
As an example, if your leg curl is only 30% of your leg extension, this shows that your quads are significantly stronger, and this has probably come about due to the way you train.
In fact, I’ll go as far to say that the only exercise that some people ever do for their “hamstrings” (in reality, all the muscles in your posterior chain) is deadlifts.
Now, don’t get me wrong, deadlifts are clearly a fantastic exercise.
However, if you’re performing back squats, front squats, leg press, leg extensions, and hack squats as well, clearly your quads are going to be a lot stronger than your hamstrings.
RELATED===>Are Squats and Deadlifts Enough For Legs?
Running vs. Sprinting
Something else that may cause an imbalance is if you regularly jog, run or sprint.
In truth, most runners and joggers are likely to be more quad-dominant.
Therefore, in the gym environment it’s perfectly feasible be moving much more weight with leg extensions than leg curls.
However, as a sprinter it’s reasonable to expect your glutes and hamstrings to be much stronger.
If you don’t believe me then compare the lower body physiques of a world-class sprinter to that of a world-class marathon runner.
So, if you do a lot of sprinting, you can generally expect your leg curls to be much stronger than the “average person”.
Finally, we have to consider various lifestyle factors, which may affect your leg extension to leg curl ratio.
A prime example of this is that many of us spend far too many hours a day sitting on our butts, and often hunched over.
This comes about from sitting at a desk or computer for a huge number of hours a day.
Plus, let’s not forget that many of us spend just as many hours hunched over staring at our phones.
Both these things can have a massive impact on the muscles of the posterior chain.
And this also typically leads to weak glutes and hamstrings.
So, it’s highly likely that you will perform leg extensions with much greater weight than leg curls.
As with any potential muscle imbalance, it makes sense to work harder on your weaknesses.
The Best Posterior Chain Focused Leg Day
So, I hope you understand that it’s extremely difficult to give a precise leg extension to leg curl ratio.
Realistically, everyone should be able to leg curl approximately 50-85% of their leg extension weight.
Many experts believe that ideally your hamstrings should be 55-60% as strong as your quadriceps.
However, personally I feel that you should be aiming closer to approximately 70% for a well-balanced physique.
There are of course various factors which may affect the “ideal” percentage.
So, it makes sense to determine your specific weakness and work on improving this.
Hi, I’m Partha, the founder of My Bodyweight Exercises. I’m someone who’s been passionate about exercise and nutrition for more years than I care to remember. I’ve studied, researched, and honed my skills for a number of decades now. So, I’ve created this website to hopefully share my knowledge with you. Whether your goal is to lose weight, burn fat, get fitter, or build muscle and strength, I’ve got you covered.