Your muscles need a day of rest in order to recover from a strength training workout, so if you are going to the gym every day, you may want to split up your workout routine into groups that you can work together. Your muscles vary in size from large groups such as your chest and back to smaller groups such as your shoulders and arms which assist many of the larger groups during your exercises.
Your chest, shoulders, triceps and the back of your upper arms are strengthened when you push a weight away from your body. For example, your shoulders contract when you press a weight overhead. Your shoulders and triceps are assistors during your chest exercises, so these three muscles are one grouping you could work on at the gym.
Your back, biceps, the front of the upper arm, and forearms are strengthened when you perform pulling movements. For example, a pull-up in which you hang by your hands and pull your body weight toward the sky uses your back, biceps and forearms. Your biceps and forearms assist in most of your back strengthening movements and these three muscles combine well during resistance training.
You may want to divide your body into upper and lower training groups. You could train your chest, back, shoulders and arms on one day and your legs and core the next day. This allows your upper body a day of rest while you strengthen the lower body and the vice versa. If you are a beginner, choose one or two exercises for each body part so as not to over train your muscles.
You may work all of your body parts on one day if you allow for a complete day of rest the next day. This type of training is comfortable for beginners, but can also be used if you are short on time, or short on available days to train during a week. When you exercise the entire body at once, choose one exercise for each body part and aim for two to three sets of eight to 10 repetitions.