I think your numbers will go down on that one. You can get used to ketosis, many people do, but five days of it and then a fast is going to really suck.
Just finished a 60 hour fast a few hours ago. 34/M/186cm/86kg. Last week was all keto, 4 weight training sessions and a 5km run on the first fasting day (Sunday, around 18 hours in). Run time was unaffected. First weights session post-fast will be tonight (i.e. after breaking the fast).
The first 24 hours breezed by, but it started getting tough around hour 42. Note this wasn't hunger - I actually wasn't hungry at all. The problem was overall lethargy and feeling foggy/light-headed. I did bounce back after a few hours though, and although I felt very weak around hour 58, mentally I felt fine. Constantly felt very cold, too.
I don't think the lethargy/weakness was due to dehydration (though drinking a lot of water on the second morning helped) or lack of sodium (was ingesting salt regularly). It could be lack of other minerals (potassium/magnesium).
The worst is that it really interferes with my sleep. It takes me hours to get to sleep and then I wake up every couple of hours.
I actually think I'm going to stop fasting for this very reason - it's not like I was doing this for weight loss, I was just experimenting to see how it felt. OMAD/IF will probably give me most of the health benefits of fasting without any of the drawbacks.
