Push-ups with feet on stairs above body's CoM -- Why does it seem harder?

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In summary: I still enjoy playing pinball!Basically, one positions oneself between parallel bars, or perhaps two chairs, with hands on the bars/support, then assuming arms are extended vertically, one bends the arms, lowers the body and the pushes up. One could support ones feet on another support (method describe by pinball) or curl legs underneath. Otherwise, between parallel bars about 1.5 m from the ground, one can keep one's legs vertically. Bench press is still best to build your pecs, seated in the machine if you have no spotters.You have a gym near you? Do they safety tour first.During Covid I did dips in the bath! You put your
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Melbourne Guy
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TL;DR Summary
If I do push-ups off the floor as you'd normally do, they're hard enough. But if I elevate my feet on stairs, so my body is horizontal at the start, they feel harder. Are they?
I've been slowly increasing my push-up count, using the traditional pose:

1657716371336.png


For a lark, I thought I would try it with my feet on the stairs, so my body is horizontal at the 'up' position with my arms fully extended. It turns out, this seems to require a lot more effort:

1657716464977.png


But am I actually doing more work, or is it just that the unfamiliar posture makes it seem that way?

I've been trying to figure out if the 'feet on stairs' position puts more weight on my arms, but I can't see that it would because the same four points of my body are supporting my weight. Or, it might be that my centre of gravity is shifted with the feet on stairs, and that causes me to be lifting more weight...but that doesn't seem right, either.

Any thoughts on whether it's all in my head? Or are my arms really trying to tell me something?
 
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More of your body weight is on your arms in the second position. It must be about 50-50. In the first position there is more weight on your feet.

Do a free body diagram!
 
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  • #3
Melbourne Guy said:
Summary: If I do push-ups off the floor as you'd normally do, they're hard enough. But if I elevate my feet on stairs, so my body is horizontal at the start, they feel harder. Are they?

I've been slowly increasing my push-up count, using the traditional pose:

View attachment 304124

For a lark, I thought I would try it with my feet on the stairs, so my body is horizontal at the 'up' position with my arms fully extended. It turns out, this seems to require a lot more effort:

View attachment 304125

But am I actually doing more work, or is it just that the unfamiliar posture makes it seem that way?

I've been trying to figure out if the 'feet on stairs' position puts more weight on my arms, but I can't see that it would because the same four points of my body are supporting my weight. Or, it might be that my centre of gravity is shifted with the feet on stairs, and that causes me to be lifting more weight...but that doesn't seem right, either.

Any thoughts on whether it's all in my head? Or are my arms really trying to tell me something?
The angle of the body changes, but the location of your center of mass does not shift.
Think of both extreme positions: standing up straight on your feet only (100% feet/0% hands), and on your hands only (0% feet/ 100% hands).
Please, see:
https://www.physicsforums.com/threads/the-physics-of-the-inclined-pushup.953338/

https://courses.lumenlearning.com/suny-physics/chapter/9-6-forces-and-torques-in-muscles-and-joints/
 
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  • #4
PeroK said:
Do a free body diagram!
Thanks, @PeroK, I've had to look that up, but I can now see why there is a difference...and why my naive thought that "my weight is my weight" wasn't quite right!
 
  • #6
Melbourne Guy said:
OMG, @Lnewqban, great link, I'm slapping my forehead that I didn't look first! Thank you for doing my research for me :oops:
I was never keen, it always hurt my lower back and gave me a headache!

Dips remove that pressure and your triceps lats and side chest still get a good burn.

Bench press is still best to build your pecs, seated in the machine if you have no spotters.

You have a gym near you? Do they safety tour first.

During Covid I did dips in the bath! You put your feet where the taps are grip either side and you can go as low as you need.
 
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  • #7
pinball1970 said:
Dips remove that pressure and your triceps lats and side chest still get a good burn.
I've actually no idea what those are, @pinball1970?
 
  • #8
Melbourne Guy said:
I've actually no idea what those are, @pinball1970?
I'll post. You young guy Yes?
 
  • #9
pinball1970 said:
Dips remove that pressure and your triceps lats and side chest still get a good burn.

Melbourne Guy said:
I've actually no idea what those are, @pinball1970?
Basically, one positions oneself between parallel bars, or perhaps two chairs, with hands on the bars/support, then assuming arms are extended vertically, one bends the arms, lowers the body and the pushes up. One could support ones feet on another support (method describe by pinball) or curl legs underneath. Otherwise, between parallel bars about 1.5 m from the ground, one can keep one's legs vertically.

One should probably keep a cushion underneath so that if one's arms collapse, or one slips, one does not receive a hard landing.
 
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  • #10
pinball1970 said:
I'll post.
Thanks, and also to @Astronuc for their description (and cushion advice), much appreciated 👍

pinball1970 said:
You young guy Yes?
Not so much anymore, @pinball1970, I'm on the short glide down side of life, now :biggrin:
 
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Related to Push-ups with feet on stairs above body's CoM -- Why does it seem harder?

1. Why does it feel harder to do push-ups with my feet on stairs above my body's center of mass?

When your feet are elevated above your body's center of mass, your body is in an inclined position, which increases the difficulty of the push-up. This is because your arms and chest have to work harder to push your body weight against gravity, making the exercise more challenging.

2. Is there a difference in muscle activation between regular push-ups and push-ups with feet on stairs?

Yes, there is a difference in muscle activation. When your feet are elevated, your chest muscles are activated to a greater extent compared to regular push-ups. This is because the inclined position shifts more of the weight onto your upper body, specifically your chest muscles.

3. Can doing push-ups with feet on stairs help build strength and muscle?

Yes, push-ups with feet on stairs can help build strength and muscle. The elevated position increases the resistance and puts more stress on your muscles, leading to muscle growth and strength development.

4. Are there any modifications or progressions for push-ups with feet on stairs?

Yes, there are modifications and progressions for push-ups with feet on stairs. You can start with a lower step or a smaller incline and gradually increase the height or incline as you build strength. You can also try variations such as wide grip or diamond push-ups to target different muscle groups.

5. Are there any potential risks or injuries associated with push-ups with feet on stairs?

Yes, there is a risk of injury if proper form and technique are not maintained. It is important to keep your body in a straight line and avoid arching your back or letting your hips sag. It is also recommended to start with a lower step and gradually increase height to avoid straining your muscles. If you experience any pain or discomfort, stop the exercise and consult a medical professional.

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