Diamond push-ups are a variation of the traditional push-up that primarily targets the triceps and chest muscles. To perform a diamond push-up, start in a plank position with your hands close together, forming a diamond shape with your thumbs and index fingers. Keep your body straight and lower yourself until your chest nearly touches the ground, then push back up to the starting position. This exercise is effective for building upper body strength and improving muscle definition. It can be modified for different fitness levels by adjusting the width of the hand placement or performing the exercise on the knees instead of the toes.