How Much Weight Do You Actually Push Up During a Pushup?

I'm sure many of you fitness gurus out there have asked yourself this question after doing a few hundred pushups. Us non-fitness gurus have had the same aching question for quite a while too. "How much weight did I just lift?" you might ask yourself after a good round of pushups. Was it 90% of my body weight? No, maybe it was 50%? Well, in this article I will calculate the percentage of your body weight that you would expect to "push up" during both regular and inclined pushups.

Before I begin with the math, lets define what a pushup is. More specifically, lets discuss proper form and technique. First, get onto the ground. Elevate your body using your arms. Your back must be straight like a board. Don't let your gluteus maximus stick into the air or hang low. There should be a 90 degree angle between your arms and the floor. Your hands should be placed about one and a half times your shoulder width apart and pointed parallel to your body. Your body should be raised on the balls of your feet. Your feet should also be touching or no more than shoulder width apart. When you go downward, only bend your elbows. You can come back up once the elbows break the plane of your back.

I will calculate the percentage of body weight resisted during a pushup for an average sized person (I used Leonardo Da Vinci's "Vitruvian Man" to properly scale the human structure because there was no other source of body measurements I could find). Since the resulting number will be a percentage, it will be correct for any person who has the same dimensions or ratio of dimensions as the average person calculated here. However, if you have abnormally short or long legs or arms compared to your height, the calculation will not necessarily be valid for you. For the purpose of the calculations, the center of gravity for a human is assumed to act through the hips.

The characteristics of an average 25 year old American male are:

• Height: 70 inches (1.778 m)
• Palm to Shoulder length: 23 inches (0.5842 m)
• Shoulder to Hip Length: 24.75 inches (0.62865 m)
• Hip to Ankle Length: 31.5 inches (0.800 m)

For Inclined Pushups, the following objects will be used for the calculations:

• Standard Chair Height: 18 inches (0.457 m)
• Standard Counter Top Height: 32 inches (0.813 m)

I will calculate the resultant forces in the hand (e.g. arms) of a human using the principles of engineering statics, Newton's Second Law of Motion, and the assumptions stated above.. The metric system will also be used to simplify the calculations.

Regular Pushups

Using trigonometry, the angle between the floor and the plane of the back is 24.1218 degrees. The horizontal distance from the foot to the hip is 0.7301 meters and to the hand is 1.304 meters.

The forces in the Horizontal Direction are zero. F_x = 0

The sum of the forces in the vertical direction are: F_Y = F_Hand + F_Foot - W = 0

The sum of the moments about the foot is M_Foot = (0.730m)×W - (1.304m)×F_Hand = 0

Because we have cleverly chosen where to place our moment equation, it is the only one we need to solve to determine the force in your hand.

1.304F_Hand = 0.730W

Therefore, F_Hand = 0.5598W

Inclined Pushups on a Chair

Here, an inclined pushup is performed on a standard chair with a seat 18 inches above the ground.

Using trigonometry and the Pythagorean theorem, the horizontal distance from the feet to the hands is 1.475 meters. The angle between the plane of the back and the floor is 39.24 degrees. The horizontal distance from the feet to the hip is 0.620 meters.

The net force in the horizontal direction is zero: F_X = 0

The sum of the forces in the vertical direction are: F_Y = F_Hand + F_Foot - W = 0

The sum of the moments about the foot is M_Foot = (0.620m)×W - (1.475m)×F_Hand = 0

Rearranging the last equation, we can relate the force in the hand to the weight:

1.475F_Hand = 0.620W

F_Hand = 0.420W

Therefore, the upward force in the hands is 42% of your body weight.

Inclined Pushups on a Countertop

Here, an inclined pushup is performed on a standard countertop with the work surface 32 inches above the ground.

Using trigonometry and the Pythagorean theorem, the horizontal distance from the feet to the hands is 1.311 meters. The angle between the plane of the back and the floor is 53.96 degrees. The horizontal distance from the feet to the hip is 0.470 meters.

The net force in the horizontal direction is zero: F_X = 0

The sum of the forces in the vertical direction are: F_Y = F_Hand + F_Foot - W = 0

The sum of the moments about the foot is M_Foot = (0.470m)×W - (1.311m)×F_Hand = 0

Rearranging the last equation, we can relate the force in the hand to the weight:

1.311F_Hand = 0.470W

F_Hand = 0.360W

Therefore, the upward force in the hands is 36% of your body weight.

Based on these calculations, we can say when you are doing a pushup, you are "lifting" about 56% of your body weight (the other 44% is held up by your feet). In other words, for an average 200 pound person, doing one pushup is similar to (but not exactly the same as) doing one repetition on a bench press with about 112 pounds of weight. Now you know about how much weight your body is pushing up during this awesome exercise.

Additionally, we can definitely say that inclined pushups require significantly less force to perform than a regular pushup. For an inclined pushup on a standard 18 inch high chair, you will lift about 42% of your body weight. For an inclined pushup with your hands placed on a standard 32 inch high countertop, it is estimate that you will lift roughly 36% of your body weight.

To verify this calculation I weighed myself on scale in both the regular and inclined pushup positions as well as the standing position. I did my best to measure the forces in my arms in the above configurations using a standard bathroom scale. It was actually pretty hard to capture the measurements with the scale on the countertop because it kept trying to slide away from me, but I eventually got it (and a good abdominal workout too!). The table below summarizes my measurements and the calculations.

Here is a Graph to help you visualize and compare the results of the calculations versus the measured values.

Based on the verification measurements, I would say that the results are a good representation of what you would expect to see in real life.

These calculations also agree with the currently published research on the matter which says that anywhere from 50 to 75% of your body weight is lifted during a standard pushup. Since everyone's body shape and weight distribution differs, the actual percentage of your weight that you lift during a pushup will vary.