Before the inception of weights, machines, genetic engineering, time travel, light sabers, or the Internet, people who wanted to get big and strong had to train using only their bodyweight. Although it originated out of “necessity,” this training method continues to be used because of its efficacy.

The methodology of bodyweight training has a long and storied history, particularly in military settings. From the Spartans to the Romans to the Navy SEALS, bodyweight only training has been a consistent component of the methods of nearly every military organization from antiquity to the present.

Admittedly, this is due in part to the inexpensive nature and the inherent convenience of not needing any equipment and being able to perform these exercises anywhere. However, expense and convenience notwithstanding, bodyweight workouts are undeniably effective for everyone from new recruits to drill sergeants.

Outside of being used in the training of the world’s greatest warriors, bodyweight exercises continue to be used in the athletic training world, and are a key component of many of the best fat loss and muscle gain workouts available, anywhere—like this one.

Within the context of a complete program that uses weights as well, bodyweight training has some specific benefits. Now, notwithstanding the fact that bodyweight exercises have been empirically proven to be effective, speaking generally, bodyweight exercises are fundamentally different from most weight bearing exercises—even when the same muscles or movement patterns are involved.

As an example, I don’t think anyone would debate that there is a tremendous difference between a bodyweight pull-up and a machine pull-down.

This fact remains true despite the fact that the same muscles—the latissimus dorsi, teres major, rhomboids, et al.—are involved; this will also remain true if one were to use the same load. That is, use weight on the pull-down comparable to your bodyweight, which acts as the load on the pull-up.

Of course, this raises the question: why are they different?

In the gym, your run of the mill meathead will tell you it’s a matter of pull-ups being “hardcore” and pull-downs being kind of a wussy exercise. The may be true, and while you know I love a good broscience argument more than anyone, that answer isn’t really relevant to your goals.

Instead, let’s focus on something substantial.

Bodyweight exercises like pull-ups, push-ups, squats, lunges, and the like belong to a group of movements known as “closed kinetic chain exercises.” Closed kinetic chain exercises include those in which the distal end of the exercise is fixed, such as a squat or lunge, where the foot remains in place. In other words, are exercises performed where the hand or foot is fixed, and does not move relative to the body.

Compare these with exercises like the pull-down, bench press, leg press, or leg curls, which are known as “open kinetic chain exercises.” In contrast to CKCEs, open chain kinetic exercises don’t have a fixed distal point. Put another way, OKCE are performed without the movement hand or foot being fixed, and instead allow movement relative to body position.

Speaking generally, if you are moving your body towards or away from an object (instead of moving an object towards of away from your body), the chain is closed; if you’re moving something either towards or away from your body (instead of moving your body towards or a way from an object).

This might seem a little academic, and while I apologize for boring you with the science, the differentiation is of vital importance when considered within the context of a complete training paradigm.

All of which is to say that bodyweight exercises are incredibly valuable, and often underused.