Which Muscles are Really Used During the Pedal Stroke?

Ever wonder which muscles you really use during cycling? No matter which kind of cyclist are you, MTB or Road or an Indoor Cyclist chances are you use the same muscles while pedaling. 

One of the most persistent myths in the mountain biking world or in general in the biking world,  surrounds the pedal stroke and goes something like this – without being attached to the pedals you can not use your hamstrings properly which forces you to rely too much on the quads the power the pedal stroke. By not being able to curl the knee joint during the upstroke of the pedal stroke you create muscular imbalances and tire out the quads faster, or at least that is what most of us have been told. However, this understanding of which muscles are used and how they are used during a pedal stroke is completely wrong and potentially dangerous over the long run.   

The photo illustration is the most common representation of the “muscles” used while pedaling. Also it is the theoretical model that is most accurate, at least in theory. 

But things are rarely the same in theory and in reality. The human body, therefore its muscles are more complex than this visual illustration that suggests mirroring each muscle during the pedal stroke. It is like the quads are doing some work and the hamstring is just sitting there waiting to be utilized.

The hamstrings are made to powerfully extend the hips while less powerfully flexing the knee, the quads are made to powerfully extend the knee while less powerfully flexing the hip. Together they both work with and counteract each other to produce lower body locomotion. Train the hamstrings to flex the hips and stabilize the knee and the quads to flex the knee and help stabilize the hip joint – that is how those muscles function in real life and how we should train them, not based on the old model of training each muscle that crosses a joint to powerfully flex it.

As you can see the Biceps Femoris (fancy talk to hamstring) is most active on the downstroke and least active on the upstroke. In fact, where first chart shows the hamstring to be most active is actually the place it is least active according to the EMG in the second picture. In other words, the first chart is flat out wrong and in no represents what is actually happening during a pedal stroke.

So this shows that the muscle groups are more complex and this can be seen when we have a complex movement like pedaling.

What does this mean to You?!

- You can ride with flat pedals.
- You should train your legs to produce a powerful downstroke using your hips.
- Have fun.