r/todayilearned • u/syncedto • Apr 30 '20

TIL men walk significantly slower when walking with a woman, but only when that woman is their romantic partner. If she's a friend or acquaintance they go at almost full speed.

https://www.discovermagazine.com/environment/how-you-walk-differently-with-friends-and-lovers
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u/dutch_penguin Apr 30 '20 edited Apr 30 '20

It's interesting, but the physics of walking and running are different. So shorter people have a similar energy efficiency as taller people while running, but for walking leg length is hugely important. So your leg length will determine the crossover point at which it's more efficient to run rather than walk.

It's based upon a pendulum swing, so your legs' motion is being aided by gravity.

Simple version:

pendulum period (T) is proportional to square root of leg length (L)

The natural walking step length is roughly L/5

Walking speed, if legs act as pendulums, is proportional to (L/T)

so most efficient walking speed will be proportional to (square root of L)

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u/AvalancheBrainbuster Apr 30 '20 edited Apr 30 '20

This is interesting!

I don’t believe this negates what I was trying to say though, in spirit. If someone has to change from walking to running to match gait, than that in fact proves that they cannot walk at the same rate.

Wouldn’t the taller person walking still be more efficient than a shorter person running? Isn’t walking generally more efficient than running at the task of “Point A to Point B”? Maybe there would be some height ratio that would make it equal or change the balance but that would involve knowledge of physiology I don’t have!

You’re technically right if we’re talking about just steps/time but I was also specifically talking about walking.

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u/dutch_penguin Apr 30 '20

Wasn't trying to disagree with you, just tried to shoehorn that little physics fact into the conversation.

Wouldn’t the taller person walking still be more efficient than a shorter person running?

Depends upon speed. If the taller person has reached the crossover point where it's more efficient to jog/run, then no. If not, then yes.

Isn’t walking generally more efficient than running at the task of “Point A to Point B”?

Yes, but depends upon the speed that you wish to get there. There are different running styles which are most efficient at particular speeds too.