Your legs are a complicated mixture of bones, muscles and connective tissues. These muscles fire in different patterns relative to their position and the movements they’re undertaking. For this reason, we can change muscle activation with different types of squats for hamstrings.
The hamstring muscles group contains three different muscles…
- Biceps femoris
They run down the back side of the femur (thigh bone), between the hips and the knee. They’re responsible for knee flexion (bending the knee). They also help to stabilize knee joints during activity.
The most common hamstring exercises are the leg curl, kettlebell swing, stiff leg deadlift and hip thrust. In this article though we’re going to explore the role of hamstring muscles during the squat exercise. We’ll look at how squat variation, range of motion and squat position affects the hamstrings in the squat.
- 1 Main muscles trained by squats
- 2 Hamstring and quadriceps activation during the squat
- 3 Squats vs. Deadlifts for Hamstrings
- 4 Tips to increase hamstring activation during your squats
- 5 Alternative squat and lunge patterns for greater hamstring activation
- 6 Squat hamstring activation
Main muscles trained by squats
Squats train the front of the thighs (quads), glutes and hips primarily, with hamstring and calf activation kicking in at different points of the movement.
We can assess the amount of leg muscle activation using electromyography, which is a technique used to measure the amount of activity performed by skeletal muscles. Another way to do so is by assessing the direct impact that a training program has on muscle mass.
In a research study titled Effects of squat training with different depths on lower limb muscle volumes, researchers found that…
The volumes of knee extensor muscles significantly increased by 4.9 ± 2.6% in full squat training (FST) and 4.6 ± 3.1% in half squat training (HST), whereas that of rectus femoris and hamstring muscles did not change in either group. The volumes of adductor and gluteus maximus muscles significantly increased in FST (6.2 ± 2.6% and 6.7 ± 3.5%) and HST (2.7 ± 3.1% and 2.2 ± 2.6%).
What this means is that squats heavily favor the quads and not the hamstrings. The hamstring really only plays a stabilizing role during the lift, and this only really becomes apparent at greater squat depth.
Hamstring and quadriceps activation during the squat
There has been a lot of research into squat training, and the role of muscles during the exercise. In a piece titled Knee biomechanics of the dynamic squat exercise, researchers found that…
‘Quadriceps, hamstrings, and gastrocnemius activity generally increased as knee flexion increased, which supports athletes with healthy knees performing the parallel squat.’
These findings were echoed by a 2022 study called Muscle Activation during the Squat Performed in Different Ranges of Motion by Women. Researchers in that study concluded…
‘The activation of the biarticular muscles RF and BF was not influenced by the squat range during the concentric action, but it was influenced during the eccentric action, with more activation at 90°.’
In English, this means the deeper the squat (greater knee flexion), the more hamstring activity (as well as the other muscles) there was. So to increase hamstring muscle activation, we need to make sure your squat movements allow for maximum knee flexion.
Deep squat = more hamstring muscle activity and better, stronger hamstrings.
Squats vs. Deadlifts for Hamstrings
These two exercises are often compared, because they’re both exercises that can involve heavy weights for the lower body. They’re also major knee flexion exercises.
What the research shows us is that hamstrings are best trained when they are positioned in a fixed, extended position. Deadlift variations which maximize time in this position are stiff-legged deadlifts and Romanian deadlifts.
It’s important to remember that there’s no better or worse exercise here, they’re good for different reasons. If you want to build big, strong and powerful quads, you should squat. If you want to build strong hamstrings and improve flexibility, you should perform one of the deadlift variations.
Deadlift variations are better hamstring exercises than squats.
Tips to increase hamstring activation during your squats
When trying to increase the activation of the hamstrings in the squat, what we’re really trying to do is increase the range of movement at the knee. The hamstrings contract more when knee flexion is increased.
Increasing squat depth
A few tips to help you increase hamstring muscle activity when squatting…
Use squat wedges
Squat wedges are plastic, rubber or wooden wedges that are placed under the heels when squatting. This has the effect of reducing the impact of tight calf muscles, which can restrict ankle flexibility and therefore squat depth.
By using wedges when squatting, you allow a greater depth. This will increase the time under tension of the muscles, improve your squat technique and recruit the hamstrings more.
Wear weightlifting specific footwear
Weightlifting shoes are designed to help improve squat technique. They have a few unique features that make them excellent for squatting and weightlifting…
- A completely flat sole, to increase foot contact with the floor and helps to keep the feet flat when lifting
- A hard midsole, so no power is leaked during the squat
- Rigid upper, which is supportive across the foot when lifting heavy weights
- A wedged-shaped midsole, which helps you to squat deeper and maintain a neutral spine in the deep squat position
A good pair of weightlifting shoes will improve your squat technique, which will in turn increase use of the quadriceps and hamstrings muscle on both legs.
Improve your ankle mobility
This one takes more time, but will benefit you more on a long term basis.
One of the limiting factors with squat depth (and therefore hamstring activation in squats) is the lack of ankle mobility. When you lack ankle mobility, your ability to flex at the ankle is restricted and you can’t get into a good quality, deep squat.
Here’s a few drills to improve ankle mobility...
Alternative squat and lunge patterns for greater hamstring activation
In this squat hamstrings article we have to look at ways to increase muscle activation patterns, whilst still staying true to the movements. Here’s a couple of similar exercises that will increase the activity in muscles, without being a dramatically different exercise…
In my personal training work, I use step ups as an exercise for people who struggle to hit great squat depth. You can do these loaded or unloaded. You have to make sure you set the box or step high enough so that when you stand on the box, your thighs are at least parallel to the floor.
This will help you to achieve more knee flexion and improve hamstring activation from a standing position.
Bulgarian split squats
Just like the step ups, split squats are an excellent way to increase squat depth for lifters who lack the ability to perform a deep barbell back squat. By encouraging greater depth, the split squat exercise also helps to increase hamstring muscle activation.
The unilateral nature of the exercise also helps to exaggerate hip extension at the top of the movement, and allows a good hip stretch.
Squat hamstring activation
What we’ve learned in the article is that when it comes to hamstring activation, squats aren’t a great exercise. The role of the hamstrings in squats is to stabilize the knee.
There are ways to increase the hamstring activation (adjust the depth of the squat), but beyond that, the hamstring is merely a part of the supporting cast. If your goal is to strengthen your hamstrings, performing exercises such as stiff-legged deadlifts, hamstring curls, and a Nordic curl are far superior hamstring strength exercises.
Building strong hamstrings will help to improve your lifting, your injury resistance and your athleticism so it’s an important thing to do.
Just don’t rely on squats to do it!