Studying for long hours continuously drains your body's capacity and hampers retaining power. JEE 2022 aspirants should study dedicatedly, but that does not imply studying for 15-16 hours. Studying 15-16 hours per day is possible but for a very short duration of only 2-3 days (if it is absolutely essential). If you are studying regularly and strategically, you require a maximum of 8-10 hours a day to nail any competitive exam.