Fasting and Working out

I have experience fasting, have done 2 seperate 3 day fasts (water only). I have also done intermittent at times. I'm vegetarian so I find it hard to get enough protein during intermittent fasting since I weight train. I'm considering doing 1 full day fast a week on one of my rest days. I work out 3 to 4 times a week (trying to sustain 4 days a week currently). Anybody have any experience fasting while strength training?