my 2c wrote:
So you dropped 1.5 seconds per pound per mile. That's 75% of the theoretical expected improvement. Solid C for effort.
It depends on your source?
The classic study determined 1.4 seconds per mile per pound:
https://pubmed.ncbi.nlm.nih.gov/723510/A more recent study found 2.4 seconds per mile per pound:
https://www.abstractsonline.com/pp8/#!/4196/presentation/10828Source consolidating this info:
https://www.runnersworld.com/nutrition-weight-loss/a20856066/how-much-does-an-extra-pound-slow-you-down/(Note that article references a letsrun thread.)
"A 1985 study found that a pair of 4-pound weights strapped to your waist increases the energy cost of running by about 4 percent; the same weight strapped to your ankles increases energy cost by a whopping 24 percent. "
(This is why shoe weight is a very important factor.)