What exercise works the rectus abdominis muscle in the midsection of your body and has many variations?

This exercise helps you develop isometric strength in your core muscles.

The targeted muscles of this exercise are pectoral (chest muscles), deltoids (shoulders), and triceps (back of your arms).

This exercise works to strengthen the muscles in your legs, hips, buttocks, abdomen, arms, chest, and shoulders. This is a full-body calisthenics workout that aims to build muscle strength and endurance in both your lower and upper body.

This exercise is similar to squats but your toes point out and you bring your arms out straight in front of you.