Regular short-term fasting? any concerns?

Good day,

I’ve been looking into water fasting more seriously for my health and I had a few questions.

it seems a lot of these fasts are long-term (>14 days) and I was wondering about the effects of several short-term fasts.

I work out a lot so I’m trying to prevent muscle loss so right now I have been doing a 5-day water fast every month and a 2-day water fast every week. keeping my diet high in protein on the days I eat.

so far I’ve seen great results, I take lots of vitamins and have been seeing noticeable improvements in the short time I’ve been doing this.

I was wondering what your opinions are of this long-term (about a year) anything I should be aware of / careful to avoid?

thanks in advance.