I'm on a keto diet. I've tried keto before with great success but I overdid it as I often do and ended up with no glycogen stores and couldn't even ride a bike for 2 minutes. I didn't know it was the cause so I ended up giving up and hence now I'm even worse off, starting over. I have learned my lesson and eat lazy keto now so it won't happen again, testing my blood sugar, ketone levels and getting blood tests at my GP.
I have never heard of having a lacte buildup in muscles before, outside of while actually training. I can't find anything on Google about it either except in diseases I know I don't have since I just had a check-up.
I'm going to do a test ride tomorrow and if an hours ride with a slow roll at the end and then stretching warm muscles doesn't help I'll go to the doctor again.
Very annoying when you after a lot of lazy years finally got a lot of energy and are seeing good progress. I'm too embarrassed to mention any watt or FTP numbers but my average watt for an hour is up by 60% since I started out. I really don't want to stop now