Hello all, I regard myself as generally quite unfit, although Fitbit says my cardio fitness is average to good at the moment (it was fair to average before) Even so, I always struggled to climb stairs, not just because of asthma and a heart murmur, but because my leg muscles hurt so much. I have lost nearly three stones in weight over the past year, which of course will help, but since starting intermittent fasting with a bit of extended fasting, I noticed I can get up three flights of stairs at work without my muscles hurting. I was so surprised that I even did another flight (went down one and back up) to see if my muscles would start hurting - they didn't. I should say that over the past few weeks I haven't been taking the stairs much due to exam season, so I've been relatively sedentary even for me. So I expected my muscles to really hurt, and am very surprised they didn't. Do you think this could be down to improved insulin sensitivity? I dont manage my diet perfectly by any means but have done a fair bit of successful fasting over the past few months.