What if Galen Rupp wore MY running shoe? Would he still have placed 2nd and 3rd (Bronze Medal) in the Boston Marathon and Rio Olympics, respectively?
I'm in the market for road racing flats. Honestly, as I age, I'm hoping to offset youth with disposable income. Currently, I train in the Brooks Glycerin, which are great shoes that I have been using the past decade. They weigh 10.6 ounces.
Here's where the math comes. In 1984, Nike funded a now famous study that concluded:
"Effects on the economy of locomotion as small as 1% can be determined using conventional oxygen uptake measurements. The effect of carrying extra weight on the foot during running has been measured at 1% per 100 g per foot."
Got it? I thought about running the math on myself. But, decided that it would be more interesting to see how history would be different if I looked at an elite runner like Galen. (Plus, I am slow even with faster shoes).
Galen ran the 2017 Boston Marathon in the Nike Zoom Vaporfly 4%, which weigh 6.9 ounces. I estimate Galen's oxygen uptake (VO2 Max) at 82.26 mL O2/kg/min (see this calculator based off Galen's 5K PR of 12:59). (In comparison, my VO2 Max hovers probably around 53 with 18:55 5K PR). Galen placed 2nd in the 2017 Boston Marathon, beating the 3rd runner by 30 seconds. He placed 3rd in Rio, beating the 4th place runner by 59 seconds.
What if Galen ran in my Brooks Glycerin instead?
My shoes weigh 10.6 ounces, which is 3.7 ounces more than Galen's Vaporflys. Each additional 100 grams (3.6 ounces) per foot requires 1% more oxygen uptake. Therefore, Galen wearing my shoes would require approximately 1% more oxygen uptake. This equates to a VO2 Max reduction from 82.26 to 82.03 mL 02/kg/min.
This VO2 Max change adds 2 seconds per mile (using the same calculator as above). That's 57 seconds over the course of a marathon.
The result:

3rd Place: 2017 Boston Marathon (losing 2nd by 27 seconds)

Bronze Medal: 2016 Rio Olympics (barely by 2 seconds  close!)
I guess time is weight  and, at least for Galen, weight is money.