Any data out there to estimate time saved running as shoes get lighter? Rule of thumb I could use?
2 seconds per mile per pound?
Data, no; anecdotal, yes. I’ve heard 1 sec per mile per ounce. Hopefully, someone will post some data that confirms/refutes.
I have read in a few places that the energy saving is estimated at 1% per 100g (=approx 4 ounces). Not sure of the source, but think the figures might have originated from Jack Daniels.
That implies that a 100g reduction in shoe weight would translate into 24 seconds over a 40min 10k race.
Out of curiosity I did some limited testing with the two shoes I use: my regular training runners and my race shoes which are about 35grams lighter (70g for the pair = approx 2.5 ounces I think). Over a few series of 1k intervals I thought I seemed to be averaging about 1 sec faster in the lighter shoes. However, given the unscientific nature of the ‘testing’, I would say that any observed difference was certainly within the margin for error/variability and not conclusive as a result.
There is no reliable data. The theory is that if you save one ounce you are saving 90 ounces a minute and over a 10k becomes pounds. A theory that it would take a great deal to figure out. So we go with subjective data.
1 . A lighter shoe feels better at the start. That’s why elite runners warm up in training shoes and put on racing flats just prior to start.
2. A lighter weight to pick up at the end of your race when your legs feel shot feels better.
So the answer is always to run in the lightest shoe you can get away with and to race in a lighter shoe than you train in.
It was Bill Bowerman who did that testing long ago. If I’m not mistaken, oxygen consumption was 1% less per 100g of shoe weight reduced…how much FASTER can one run as a result, don’t know if that specifically has been studied.
meant to post a link to this. summary of a few different studies discussed.
Most relevant section:
“The next relevant study was by Catlin & Dressendorfer (1979) where the authors, apparently, looked at the effect of shoe weight on the energy cost of running. Since I am unable to get hold of the article and PubMed does not have an abstract for it I am limited to recounting what Jones et al. (1986) state about it. The study looked at marathon runners, on a treadmill wearing lightweight racing flats (520g total weight). They recorded a 0.9% increase in energy cost for each 100g increase in shoe weight (per pair).”
520g for racing flats? Wow technology has advanced in 25 years for sure. My flats are 242g (Mizuno Universe 3) and 398g (Brooks T7 Racer) per pair in size 11-11.5
yeah. i noticed that too.
I am also a big Brooks fan. have a pair of the GTS and GTX - both are around 330g (european size 9 / 44) and would not be considered lightweight flats by any stretch
520g for racing flats? Wow technology has advanced in 25 years for sure. My flats are 242g (Mizuno Universe 3) and 398g (Brooks T7 Racer) per pair in size 11-11.5
I think the authors just had different standards about what constituted a racing flat. My Air Pegasus trainers from 30 years ago (size 10.5) weighed around 300 grams . My Nike American Eagle flats certainly a lot less than that.
520g for racing flats? Wow technology has advanced in 25 years for sure. My flats are 242g (Mizuno Universe 3) and 398g (Brooks T7 Racer) per pair in size 11-11.5
I think the authors just had different standards about what constituted a racing flat. My Air Pegasus trainers from 30 years ago (size 10.5) weighed around 300 ounces. My Nike American Eagle flats certainly a lot less than that.
Those are some heavy kicks! No doubt the others would be lighter. 
Seriously dude. We made them out of concrete back in those days
(Corrected my post :-))
1% per 100g saved.
Looking at weight alone is a poor way of determining if a shoe is fast. There are two equally (if not more) important characteristics that easily offset 3-4oz of weight.
Just moved from a 6.3 oz shoe last season with a PR of 6:10 per mile 10k average to a 3.9 oz shoe this ear with a 6:12 per mile 10k average. So…lighter shoes make you slower.
Those would be??
Just moved from a 6.3 oz shoe last season with a PR of 6:10 per mile 10k average to a 3.9 oz shoe this ear with a 6:12 per mile 10k average. So…lighter shoes make you slower.
Nah, put them on your feet instead of your ear and you’ll run faster
Just moved from a 6.3 oz shoe last season with a PR of 6:10 per mile 10k average to a 3.9 oz shoe this ear with a 6:12 per mile 10k average. So…lighter shoes make you slower.
Nah, put them on your feet instead of your ear and you’ll run faster
That’s weird, I “heard” they were faster.
Who really knows, but racing flats just make you feel fast, and I think that confidence counts for something. In my experience; feel fast=run fast. Though I like the one ounce = 1 second per mile.
I think the issue gets more complicated with distance as “carrying” energy may be negated by less attenuation, not to mention the kinematics. Newer materials and design are bringing all the numbers down. I have been running for a loooong time and can tell you my shoe requirements have not changed much relative to cushioning and stability for long distance, but now find myself in a 9-10 oz shoe versus 12-15 15 years ago. I can get away with less for a 5K, but that same shoe would kill me in anything over 10 miles.