Prohibition of Fasting for a lifetime for the one who will be harmed by that or who will neglect other duties, or does not break his fast on the two 'Ids or during the days of At-Tashriq; It is better to fast alternate days — Sahih Muslim 1159 d

The Messenger of Allah (ﷺ) said to me: Recite the whole of the Qur'An during every month. I said: I find power (to recite it) in a shorter period. He said: Then recite it in twenty nights. I said: I find power (to recite it in a shorter period even than this), whereupon he said: Then recite it in seven (nights) and do not exceed beyond it.