I am almost 2 years post op 2 level lumbar fusion. low back pain has improved but still having issues with back muscle tightness/muscle fatigue. exercise regularly, weights, walking, yoga. advice?

Stretch: Before exercising. This is really important as it will help increase your strength as well as decrease injury. Get a loved one to give you a massage or get a professional one on a regular basis.

Everything Right: It sounds like you are doing everything right. Surgery is traumatic to the spine and muscular tissue. There can be irreparable damage as as result. Overall, it sounds like surgery was a success because you have an active lifestyle. I would recommend a short course of physical therapy so they can discuss your goals and deficits you have. You may be doing the wrong exercises. Discuss with doc.