# Any published biophysics or sports physics research on how much top running speed might change on Mars or the Moon? (Indoors, not in a suit.)

Thanks for reopening!: How fast could a person run on the Moon? asks for users to make their own conclusions. Here I'm making a reference-request for research and results.

Related but different: How would you move in low gravity without a suit?

So I think this can be reopened.

This silly video shows an idiot running across the surface of Mars in a space suit with big boxy boots, constantly looking at his wrist computer instead of obstacles. It is "based on Mars gravity simulations on Earth" and shows a top running speed of 44 kph, or roughly 17% faster than the record sprint on Earth.

Question: Have there been any published serious biophysics or sports physics attempts to calculate by roughly how much top running speed might change in Mars' or the Moon's gravity? (Indoors, not in a suit.)

note: The issue of running speed in reduced gravity has been introduced and discussed at length in How fast could a person run on the Moon? and its associated answers. Here I'm looking for a formal study, preferably peer reviewed if available, and including Mars if possible. That may be tough — it may be hard to find many peers in reduced-gravity running physics.

below: A lot of motion, torque, and work are required to move human legs back and forth to match ground speed and continue to accelerate faster. From here.

below: This requires substantial muscle at low moment locations within the leg. From here.

below: GIF from screen shots of the Zaptec video Born to Run. Appears to be almost effortless — "based on Mars gravity simulations on Earth."

• A related, but more generalized question along the same lines.
– uhoh
Apr 12, 2017 at 0:37
• @kimholder wow lots of goodies there! I've adjusted the title to match the body of the question, where I had asked "Have there been any published, serious biophysics or sports physics attempts to calculate..." It looks like it is not answered there. I don't see any discussion of torque - angular acceleration of the leg to keep up with ground speed. However there is lots of helpful information there, so I've added and edit and referenced it as well. Thanks!
– uhoh
Apr 12, 2017 at 2:43
• I don't think that focusing on studies sufficiently distinguishes this from the previous question for it to stand on its own. Answers on this site are often supported by relevant studies, especially in cases like this, where concise answers aren't possible and there isn't a broad consensus within the field. A proper answer to the previous question would need such a reference. I looked for such a study and didn't find anything, also - though i don't have access to academic libraries or anything behind a paywall. Apr 12, 2017 at 17:12
• @kimholder the other question zeros in from the start on forces against the surface and air friction. It predefines which parameters are important and excludes others, including the torque needed to move the inertial mass of the legs forward and backward. Marking this incorrectly as an "exact duplicate" of an over-specified question ensures neither will get a good answer. Why not free my question up? Or if you must kill my question, at least fix the other one?
– uhoh
Apr 12, 2017 at 18:56
• The old question has problems, and i've looked at it before without coming up with a good solution. It asks it be assumed a stance that adapts well to the lower gravity is possible, which is open to question. It could stand to lose the partial atmosphere part. It is specific because i need to look at how it would work in a colony that has had time to adapt the best approach, that part i'm okay with, and it's why i never got rid of the stance part. It still covers the aspect of 'has there been a study'. If you're interested in normal running, that could make this different. Apr 12, 2017 at 19:46