Since there's all these physics questions...

yesterday at the gym, i saw some guy put 20 lbs of freeweights in his backpack and use the stepmill.
I think he is stupid, cuz on a stepmill, you're not really bringing up your center of gravity, only lifting your legs. Your legs still weigh the same, no matter how much u lug on your back. Adding weight to yourself does nothing except put extra stress on your straight leg.

Am i wrong?

 

yes.

 

No.

 

maybe so

 

i don't know, but he was probably stupid anyways.

 

carry a weight up the stairs in your house. then walk up the stairs with no weight. which is harder

 

If his body rises and falls when he steps on the "step mill" than carrying the weight does add to the work out. If his body stays in place and only his legs rise, then the weight does nothing.

 

Just because the step is lowering at the same rate his leg is pushing his body up, doesn't mean his leg isn't doing any work. Carrying more weight will increase the workload on his legs.

 

1st sentence, absolutely, his legs are doing the work. They are pushing the step down. If the weight does not rise, he is doing no additional work. Simple physics. Now if the weight actually rises with each step and then falls over and over, he is indeed doing more work with the weight.

 

ok you're either dumb or have no idea what a stepmill is.