Grasp a pull-up bar using an underhand grip, with your hands shoulder-width apart.
Hang from the bar.
Exhale as you pull your body up until your chin is raised above the bar.
Hold for a count of two and squeeze your biceps and back muscles.
Inhale as you slowly lower your body back to the starting position.
Repeat for the prescribed number of repetitions.
Comments and tips
Use the chin-up, a major compound bodyweight exercise, to build the size and strength of your upper body, especially your back and elbow flexors.
The chin-up activates the biceps brachii more than the pull-up does because the forearms are supinated with the chin-up but pronated with the pull-up.
For best results, move through the full range of motion.
Engage your core to keep your body straight throughout the exercise.
To make the chin-up easier, use an assisted pull-up machine. If you have no access to an assisted pull-up machine, tie a long exercise/resistance band to the bar and place one foot inside the loop that the band creates. Perform the chin-up as instructed above. You should feel the band assisting you as you pull your body up.
To make the chin-up more difficult, either use a dip belt with additional weight or hold a dumbbell between your feet.