The rule of thumb i have heard from is 2 secs per pounds per miles
Is there any bigger for slower runners like 2.6 s /lbs/mile?
For a 30min 10k runner who loses 3 kg which is 6.6 pounds
That is : 6.6 pounds x 2 s x 6 miles = 82.69s
That translates to 28m37s 10k
What a big improvement!
2 seconds per mile is roughly accurate but you are not going to find too many 30 minute 10K people with nearly 7 pounds to spare, they'd already be pretty lean
It's a rough estimate and it's fairly accurate, just don't look too far in to it.
this has always perplexed me so much as a relatively built runner (5'11, 160lb). I have ran competively for 7 years, and I don't think losing weight would benefit me at all, but I've always heard this 1-2 secs/lb/mile stuff. I guess it's maybe talking about losing a pound of fat and not muscle?
To a certain extent, muscle also factors in. http://www.runnersworld.com/race-training/your-fastest-weight
trackboat wrote:
this has always perplexed me so much as a relatively built runner (5'11, 160lb). I have ran competively for 7 years, and I don't think losing weight would benefit me at all, but I've always heard this 1-2 secs/lb/mile stuff. I guess it's maybe talking about losing a pound of fat and not muscle?
Here's a more accurate formula:
(Current VDOT) x (Current Weight/Goal Weight) = Goal VDOT
So let's take an age grouper with a 15:54 current 5k (VDOT of 65) and a weight of 148. (Kilos or pounds obviously don't change the formula.)
If he cuts his weight to 142 and loses no fitness, then his new VDOT is 67.75, and his projected 5k is roughly 15:21, or 1.77 second per mile.
It may depend on the individual. I'm a female in my 30s (yeah yeah insert mom jokes here) and I am 5'8" and 125 lbs. I've actually found myself gaining a few pounds since I've added in track workouts. It's leg muscle that I didn't used to have. I'm faster now than when I was 122 lbs.