4 ms·

How much of that is due to only using two limbs? Which also makes us slower I guess.

derektank 1y ago
There is actually some evidence that, in a sprint, humans might be able to run faster on all 4 limbs than on 2 https://pubmed.ncbi.nlm.nih.gov/27446911/ https://pubmed.ncbi.nlm.nih.gov/27446911/
- _Algernon_ 1y ago
  >some evidence https://xkcd.com/605/ https://xkcd.com/605/
  - derektank 1y ago
    I think it's sort of reasonable in this case, given there's very little investment in running on 4 limbs, while nation states fund track and field programs to the tune of millions of dollars. That the small number of 4 limbed runners are making progress against 2 limbed runners does indicate it might allow higher peak performance. Of course, 4 limbed runners have probably already plucked the low hanging fruit in performance improvements, but the researchers aren't projecting linear improvement
    - jessekv 1y ago
      Don't sprinters start with 4 limbs on the ground? The advantage of the 4 limbs seems to be gone by the second step. Trail runners often run with poles on up or down hills. Not sure about top speed, but from experience the poles definitely help with endurance.
- kbutler 1y ago
  The article was published in 2016, and the authors extrapolated from 7 data points (!) over about 7 years of progress in the world record. This is obviously insufficient to project 30 years into the future. https://pubmed.ncbi.nlm.nih.gov/27446911/#&gid=article-figures&pid=figure-1-uid-0 https://pubmed.ncbi.nlm.nih.gov/27446911/#&gid=article-figur... That record progressed 2008 18.58 2015 15.71 2.87 seconds over 7 years. https://en.wikipedia.org/wiki/Kenichi_Ito_(athlete) https://en.wikipedia.org/wiki/Kenichi_Ito_(athlete) If we check in on more recent progress since then, we find the current record is 15.66 set in 2022. https://web.archive.org/web/20241222175947/https://www.guinnessworldrecords.com/world-records/88771-fastest-100-m-running-on-all-fours https://web.archive.org/web/20241222175947/https://www.guinn... Another 7 years, for an improvement of 0.05 seconds, or about 850 years of linear improvement to reach Bolt's 9.58 seconds. Anyone wanting to bet on beating Bolt by 2048?
dehrmann 1y ago
It's a tradeoff. Having two general purpose limbs is useful for all sorts of things, but not escaping scary things, so endurance can somewhat make up for that.
tim333 1y ago
Two limbs combined with afro hair (https://en.wikipedia.org/wiki/Afro https://en.wikipedia.org/wiki/Afro) which acted as a sun shade allowed humans to move faster and longer at midday in Africa than most of their prey. Lack of sun hitting the body being upright plus sweat from the largely hairless skin made them overheat less than the prey.

There is actually some evidence that, in a sprint, humans might be able to run faster on all 4 limbs than on 2 https://pubmed.ncbi.nlm.nih.gov/27446911/ https://pubmed.ncbi.nlm.nih.gov/27446911/

_Algernon_ 1y ago
>some evidence https://xkcd.com/605/ https://xkcd.com/605/
- derektank 1y ago
  I think it's sort of reasonable in this case, given there's very little investment in running on 4 limbs, while nation states fund track and field programs to the tune of millions of dollars. That the small number of 4 limbed runners are making progress against 2 limbed runners does indicate it might allow higher peak performance. Of course, 4 limbed runners have probably already plucked the low hanging fruit in performance improvements, but the researchers aren't projecting linear improvement
  - jessekv 1y ago
    Don't sprinters start with 4 limbs on the ground? The advantage of the 4 limbs seems to be gone by the second step. Trail runners often run with poles on up or down hills. Not sure about top speed, but from experience the poles definitely help with endurance.
kbutler 1y ago
The article was published in 2016, and the authors extrapolated from 7 data points (!) over about 7 years of progress in the world record. This is obviously insufficient to project 30 years into the future. https://pubmed.ncbi.nlm.nih.gov/27446911/#&gid=article-figures&pid=figure-1-uid-0 https://pubmed.ncbi.nlm.nih.gov/27446911/#&gid=article-figur... That record progressed 2008 18.58 2015 15.71 2.87 seconds over 7 years. https://en.wikipedia.org/wiki/Kenichi_Ito_(athlete) https://en.wikipedia.org/wiki/Kenichi_Ito_(athlete) If we check in on more recent progress since then, we find the current record is 15.66 set in 2022. https://web.archive.org/web/20241222175947/https://www.guinnessworldrecords.com/world-records/88771-fastest-100-m-running-on-all-fours https://web.archive.org/web/20241222175947/https://www.guinn... Another 7 years, for an improvement of 0.05 seconds, or about 850 years of linear improvement to reach Bolt's 9.58 seconds. Anyone wanting to bet on beating Bolt by 2048?

dehrmann 1y ago

It's a tradeoff. Having two general purpose limbs is useful for all sorts of things, but not escaping scary things, so endurance can somewhat make up for that.

tim333 1y ago

Two limbs combined with afro hair (https://en.wikipedia.org/wiki/Afro https://en.wikipedia.org/wiki/Afro) which acted as a sun shade allowed humans to move faster and longer at midday in Africa than most of their prey. Lack of sun hitting the body being upright plus sweat from the largely hairless skin made them overheat less than the prey.