Left/Right Power Imbalance

I had left knee replacement surgery early in 2020, and to help gauge my recovery, I bought Assioma power meter pedals to measure true L/R balance. Because I had arthritis for years prior to surgery, I knew my left side was weaker (and visibly smaller). Initial rides a few months after surgery confirmed this. Recently I was thrilled to get readings of 48/52 and even 50/50 — on my trainer. But on outdoor rides I’m still getting 40/60 or 42/58.

I realize that riding outside forces you to recruit and coordinate more muscles, but would that really account for readings so different? And am I putting too much stock in these readings? Curious to know what folks think.

To give you an idea of how personal this obviously is, I have an arthritic left knee but my left leg is markedly stronger than my right! I also show a difference in power imbalance inside and out but it’s greater inside. It also evens out as my power increases going to 50/50 at 5/6min power. It also evens out as I fatigue, presumably because whilst one leg is working at sweet spot the other is only at tempo LOL. Not much help but I’m starting to stop worrying about it. It is what it is.

Carytb, do you get dramatically different results between riding your trainer and riding outside? That’s what’s confusing me. I was trying to use the L/R split to monitor improvement, yet the readings are so different

Yes. I’ve put it down to the bike moving around outside and me standing up and also moving around more. My fit might be a bit different on the outside bike as well.

OK, I’m gonna just quit worrying about it :slight_smile:

1 Like