You are running a race on a low-gravity world. What is the optimal stride?

Factual Questions
1

The moon has c. 16% of Earth’s gravity, while Mars has 38%. The Apollo astronauts learned to do this hop-walking thing to get around efficiently, but if you assume an Earthlike atmosphere (thus no need for a bulky spacesuit), then how exactly would you run if you were trying to win a race? In lunar gravity, I’d imagine that Usain Bolt would go sailing 6 feet into the air using his normal stride, and of course any air time means you aren’t pushing off of the ground to increase/maintain your velocity. Anyone want to hazard a guess as to the optimal stride?

2

I’d imagine a really low, cheetah-like sprint using all fours would work well. That’s kinda what they use to traverse around the ISS. They use their arms to grab on to stuff then just launch themselves into the next room.

3

I’m picturing a motion more like a speed skater.

A typical running stride is basically a series of little jumps. Maintaining anything like that in low gravity will inevitably result in too much time spent in the air, which you pointed out is bascially wasted.

So what if one instead used a more lateral motion, pushing off an some diagonal that isn’t exactly straight forward? That would remove the ‘bounce’ of the body having to more or less ‘jump’ over the leg, and it would allow the leg to push the body in a direction much more parallel to the ground.

Edit - Ok, maybe less like a speed skater than I previously envisioned.

4

According to all the SF stories I’ve read, the quickest way of travel is likely to be quite similar to a kangaroo hop.

5

A couple of possibilities:

  1. Pretty much the same stride rate and distance one uses on Earth, except you would learn not to exert so much downforce with each footfall.

  2. same downforce per footfall, but much greater length of time between footfalls. This would be something like the bounding stride used by the Apollo astronauts, except with much more leg flexion (the suits limited those guys), and therefore the ability to travel faster and with a longer stride than they did.

#2 might be more difficult: with a far greater length of time between footfalls, there is greater opportunity for your body to achieve a problematic orientation before the next time your foot contacts the ground and is able to apply corrections. I would expect stumbles/falls to be more common with #2 than #1.

I would guess we probably can’t run any faster in different gravity because we are limited by how fast we can push forward with our feet, and we already run at that limit on earth; if our bodies move forward any faster than that, our feet can’t keep up, and we fall on our faces.

6

I used to run track and even though it has been a long time I still remember the feeling that my feet and legs were ready to push off again but I was waiting to hit the ground so I could do so. This would be exagerated greatly on the moon.

7

But you assume the surface of the planet is extremely rocky in order to have lots of handholds? I think that running in a pool might give some insight as you don’t have much friction on the ground due to the decrease in gravity owing to buoyancy. But this has the drawback of the viscosity of water- however you don’t see anyone “crawling” on the bottom of a pool to move quickly. So I think the most efficient would be leaning more forward to aim the power down but very similar to natural human gait. This would definitely be the most energy efficient. A four limbed scramble may be faster but I don’t more optimal (any recombent cyclist will tell you that you have to learn to breath less deeply).