Hey
Most I’ve ever done fasting is 36 hours. I don’t have any issues, but I do tend ease off a little. On my hard days, don’t beat myself up about not hitting my splits, etc.
I exercise 5 or 6 times a week and most days twice a day. Cardio in the morning and strength afternoon.
I always do my cardio fasted anyway. I can run anywhere up to about 10 miles, no problems. Track work or hill sprints is a little harder on extended fasts, especially if I am hitting it hard.
I tend to ease off a little on my strength training though especially my legs. I just get really carb hungry after a leg session.
Make sure you’re taking electrolytes, and you will be fine.
I don’t typically do much cardio when I exercise, I mostly lift weights.
Depending on how I feel on a fasting day I might just take a long walk if not able to lift weights though. It seems for me slow steady movement is better than anything more intense when fasting.