Ask the Physio

Specialist cycling physio Dan Guillemette has a solution for every niggle

- David Bradford

I have noticed a big difference in power between my left and right legs when cycling. I do not have any pain, but feel blocked on one side. Can you help?

When it comes to power production, the general rule of thumb is that up to a four to five per cent (i.e. 48/52) variation between legs is acceptable. Once you start noticing a constant significant difference in power production between left and right legs (i.e. 45/55), it needs investigating.

Cycling is about linear symmetry, and one potential cause of dysfunction is if you have had a recent crash or injury that has resulted in some malalignment, especially around the pelvis and hips. Pain inhibits good muscle function, and the combination of the two will change your muscle recruitment and activation. This will affect your ability to stabilise the pelvis and lower limb during the power phase of the pedal stroke. It is important, especially if there has been a crash, to check if there is any damage to your equipment, especially the saddle.

Alternatively, imbalance can be a result of poor positioning and a lack of endurance capacity and robustness for the type of cycling you are doing. This is common among those new to cycling and those who have recently increased their activity (training load).