Hey there! I’m currently on day 6 and yesterday was pretty much like that for me! I didn’t feel like complete death but I just felt off and shitty like my electrolytes were off and noticed a bit more heart palpitations but kept drinking my electrolytes. Today I woke up completely fine feeling way better and I’m not exactly sure why this happens. I supplement with a men’s multivitamin, snake juice (1tsp salt lite/no salt brand, 1/2tsp of pink Himalayan salt, and 1tsp of baking powder all in 1L of water) and about maybe 750mg of magnesium spread throught the day. I’ve read some other posts awhile back, not sure if it’s true, but some people would say that it’s similar to withdrawals and your body is going through fat that’s been in your body for awhile causing you to feel like shit. Now I’m no scientist so I can’t validate whether that’s true or not but that’s as much as I got out of it. I’m shooting to break my record of 12 days and everyday I feel like I’m learning something new about my body and how it reacts to too much supps, too little supps, drinking too much fresh water, or even not enough. Good luck on your journey and keep strong! Know when to keep going and know when to listen to your body!
That’s definitely not enough potassium and depending on what kind of magnesium you are taking, it’s possibly not enough magnesium (as most magnesium does not have 100% bioavailability, some kinds are as low as 3%!)
To me, the words that jumped out were “after my workout”, which makes it sound like you’re regularly working out during your extended fasts. That is asking a lot of your body. Just because you can exert yourself despite not having eaten for a week doesn’t mean your body’s going to be particularly happy about it.
To me, common sense suggests that collapsing into bed for two hours after a workout is a pretty good sign that your body is having trouble coping with the demands you’re making on it. You started your fast at a low body fat percentage, so there wasn’t a lot there for it to burn, and you’re constantly damaging muscles that aren’t receiving very much new protein to repair them.
My general advice is that if fasting causes mood issues, push through it, but if you’re running into objective evidence of physical failure, you need to listen to your body and ease up - stopping all the exercise would be a good start.