Serum creatinine back to 2.0 mg / dL. Why?

My most recent blood test had a pleasant surprise. According to the results, my blood creatinine level is back to 2.0 (pretty much where it was when I was first diagnosed with CKD, 15 years ago). This was a surprise as tests during the last fives where all above 2.5.

I don't think my kidney function has improved but this result may at least mean it's not worsening as much as I thought. My current theories for the results are:
1. I have been exercising less lately. Perhaps the elevated creatinine levels were due to doing more exercise.
2. Inaccurate test results!

The next time I test, I'll try doing more exercise beforehand to see how much that seems to impact the results.


Current lifestyle/diet: No meat or chicken, low cheese/milk (some yogurt), low wheat, oats+berries+chia+olive oil for breakfast, fish a few of times a month, commonly eat: lentils, vegetables, fruits, potatos, rice, corn tortillas, peanuts,