The biceps brachii is one of the most often trained muscles. stereotypically most guys want big biceps - and in practice, this is often true. As is commonly known, the main function of the biceps brachii is elbow flexion (what occurs during a curl exercise). However, the biceps have far more responsibilities than just curls.
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Bodyweight
Chin-Ups
Difficulty: Intermediate
Grab the bar shoulder width apart with a supinated grip (palms facing you)
With your body hanging and arms fully extended, pull yourself up until your chin is past the bar.
Slowly return to starting position. Repeat.
Inverted Row
Difficulty: Beginner
Lay underneath a fixed horizontal bar and grab the bar with a wide overhand grip.
Pull your body straight up to the bar.
Return to the starting position, your arms fully extended. Repeat.