Do you think that you should exercise your muscles individually (different muscle each day) or exercise your whole body every day?

Training all the muscle groups in same day, which in other words called Circuit training is recommended mostly for females but not more than 2-3 times/week for conditioning and toning. But if you are looking to increase your muscle mass, split routine is what recommended, which means 1-2 different muscle groups in a day. This allows you for better recovery and hypertrophy.