Lower back pain cycling can be caused by a multitude of reasons. The more common causes and solutions are listed below, fix the problem before it gets out of control and stops you completely.
Bike Fit
Many people do not like to spend money on one of the most important areas of cycling… Bike fit. A proper bike fit will save you from serious amounts of pain and frustration along with delivering more power to the pedals and a more comfortable ride. It is all too common for a cyclist to be too stretched out on a bike or too low.
Try shortening the stem or raising your bars. Ultimately, a professional bike fit is well worth the cost.
Weak Core
Many of us cyclists have very strong legs but have spaghetti like cores. I have always tried to build myself like a pyramid (stronger base, relatively weaker upper body) however, if your core is too weak then your legs have no platform to push off of. With a weak core power will not be transferred into the pedals, but rather be lost in your flexing torso, eventually resulting in a very fatigued and overworked back that may spasm. Riding with a weak core is like riding a cracked frame.
If you have lower back pain cycling often times the fix is core strengthening exercises.
Flexibility
Flexibility is another culprit when it come to a sore back while cycling. My problem is that I have very tight hamstrings which pulls my pelvis out of alignment during each pedal stroke causing my lower back to scream after doing the work other larger muscles should be doing. Tight quads and backs also contribute to back pain.
Find out what your limiter is and stretch it out.
Posture
Back pain is a result of all of the stress put on your back. Posture may be the most significant factor in the average cyclist. Many of us spend far too much time sitting in chairs with little to no back support causing our backs to round and stress. When we are not sitting we are walking hunched over or lifting things with a rounded back. It is important to keep an arched back and stay very focused on maintaining proper posture.
Purchase some back support for your chair or roll your back on a foam roller to “reset” your back to normal. (I do this a minimum of once a day… I am borderline obsessed with foam rollers)
Leg Length Discrepancy
I believe most people over diagnose leg length discrepancies. Find a quick test in knee pain cycling – causes and solutions post to see if you have a different leg lengths. Bike fitters will try and shim cleats for a discrepancy greater than 6mm; however, I find that some days my left leg is shorter and other days my right leg is shorter.
Test them over time and if one is continually shorter than the other then add the shims.
Riding Style
Even riding style can cause lower back pain. If you like to push a large gear then that can put unnecessary strain on your back, especially while climbing up a hill.
Try spinning instead of grinding, also get out of the saddle once in a while and stretch out your back.
Serious Issues
If you have a herniated disk no amount of core work outs, stretching or bike fit changes is going to help, go see a doctor.
Lower Back Pain Cycling
I purchased a great book called Foundation: Redefine Your Core, Conquer Back Pain, and Move with Confidence by Eric Goodman. The book teaches you proper movement patterns by strengthening the posterior chain to maximize power, flexibility and endurance. If you have back pain it is imperative that you remain vigilant to cure the problem. This book keeps what is important top of mind.