Complex sentence: Pull ups are one of the best ways to measure the upper body strength of the "pulling muscles" is commonly used by armed forces as the United States Marine Corps use this exercise as a vital way to determine strength among servicemembers.
Split into simpler sentences: Pull ups are one of the best ways to measure the upper body strength of the "pulling muscles". They are commonly used by armed forces, such as the United States Marine Corps, as a vital way to determine strength among servicemembers.