I always fast twice a week for 24 hours on work days. Always get stronger and gain muscle doing this mostly i believe due to increased insulin sensitivity. I eat a good surplus on training days and hold weight and get stronger and leaner, if i want to cut I eat maintainece on training days and hold strenght while lossing fat quick. If I want to bulk I increase size of meals on refeed. I do this in combination with carbless post workout and carb backloading on work days whennot fasting. Insulin sensitivity is through the roof. Your find studies for and against anything. I just try shit and see what happens, If it works i like to understand why, but even if i cant explain it and it works I do it. For instance if i train after a 12 hour night shift and 5 hours sleep, feel like shit, no pre workout drink, hit personal bests nearly every time. I can't explain why or find and plausible explanation why. It works, so i do it. Same with fasting, love it