The Prophet (Peace and blessings of Allah upon him) used to do much prayer, fasting, dhikr, supplication and other kinds of worship. And when he performed an act of worship he would continue with it and do it regularly. `A'ishah reported, "When he (Peace and blessings of Allah upon him) missed his night prayers due to pain or something else he (Peace and blessings of Allah upon him) would pray twelve rak`ahs the next day." (Muslim)