Weight loss effect on times

Use the search. There's been threads on this before. I've read your times improve by .625 percent for each kilogram lost. I've heard other things though too.

cheers mate!

all things being equal....when I would drop 5-10 lbs, my racing times would improve quite a bit, not to mention training faster and easierl.

I'll add that I just feel smoother during my runs when I'm lighter. I gained weight this year and felt really awkward until I lost some of the weight. I'm still a bit heavier than I used to be and still don't feel as smooth while running.

Up to 1.5sec/mile/lb

I've read your times improve by about 20 secs./mile for every 5 pounds lost but that seems a little high to me.

If you use, perhaps misuse a little, the Charts in Daniel's Runnning formula (page 63& 64 of the 1998 version) you can see the effect. I find the charts do a great job of predicting my race times at different distances based on a recent race performance. Anyway, if you take your current weight and devide it by the target weight and then multiply that by the current VDOT you can reasonably well predict your target VDOT at target weight. It has worked very well for me. Of course my weight and the amount I am training are definitely correlated, so the lighter I get the faster I go. I am certain there is a point where this does not hold up - but I am no where near the 6% body fat range.

A famous JC coach said 1 lbs. = 1 min. in the marathon. That would be about 2 1/4 sec/mile. I don't know.

I have read other stories but never found anything definative.

During college days over 30 years ago a friend was on a huge weight loss program. He started running when getting thinner. Every month I timed him in the mile. He then stopped running. A month later without running a step but losing 20 lbs., he ran his mile 20 sec. faster than the previous month. That really opened my eyes to the importance of weight in running.

Interesting descussion.

ChemD wrote:

If you use, perhaps misuse a little, the Charts in Daniel's Runnning formula (page 63& 64 of the 1998 version) you can see the effect. I find the charts do a great job of predicting my race times at different distances based on a recent race performance. Anyway, if you take your current weight and devide it by the target weight and then multiply that by the current VDOT you can reasonably well predict your target VDOT at target weight. It has worked very well for me. Of course my weight and the amount I am training are definitely correlated, so the lighter I get the faster I go. I am certain there is a point where this does not hold up - but I am no where near the 6% body fat range.

using JD's vDot input old weight old vDot new weight

outputs new vDot:

I've often wondered about this myself. I've had friends who have improved their times as their weight dropped but they were also training extra hard. So did they improve from hard training or the weight loss? Probably both but I can't tell by that what percentage.

I typically calculate 2.7 sec per mile per pound of unnecessary tissue that you lose. It will vary with your ability level, but you have the idea -- (1) multiply your VDOT times your body weight in kg (pounds X .454 = Kg). (2) This will give your an absolute value for estimated VDOT (3) subtact the anticipated weight loss from current weight and (4) divide the new (lighter) weight into the Absolute VDOT value that you got in #2 above. This will give you a new VDOT to use for calculating performances. Naturally, the catch is that you must be getting rid of body mass that is not useful to your running. If you try to lose too much to make these mathematics look even better, you will start to lose muscle mass and the absolute VDOT value will decrease as fast or faster than the body mass is reduced and VDOT used for determining performances will not be to your liking

jtupper wrote:

I typically calculate 2.7 sec per mile per pound of unnecessary tissue that you lose.

Always appreciate your input jtupper.

Is the 2.7 sec per mile per pound formula for the marathon?

And does a lighter weight have more effect on marathon times then 1500 times?

Med Sci Sports. 1978 Fall;10(3):194-9. Related Articles, Links

Effect of experimental alterations in excess weight on aerobic capacity and distance running performance.

Cureton KJ, Sparling PB, Evans BW, Johnson SM, Kong UD, Purvis JW.

To experimentally investigate the effect of excess body weight or fat on maximal oxygen uptake (Vo2 max) and distance running performance, the metabolic response to maximal and submaximal treadmill running and the 12-min run performance were measured in six subjects under each of four added-weight (AW) conditions: normal body weight and 5, 10, and 15% additional external weight, added to the trunk. AW was found to systematically and significantly decrease Vo2 max expressed relative to the total weight carried (ml/min.dg TW), maximal treadmill (TM) run time and 12-min run distance, but not to systematically affect Vo2 max (1/min) or Vo2 max (ml/min.kg FFW). An increase of 5% AW was found, on the average, to decrease Vo2 max (ml/min.kg TW) 2.4 ml, the TM run time 35 sec and the 12-min run distance 89 m. These decreases were a direct consequence of the increased energy cost of running at submaximal speeds. It was concluded that changes in excess body weight can influence Vo2 max expressed relative to body weight and distance run performance independent of any change in cardiovascular capacity. Failure to distinguish the metabolic effects of body fatness from the influence of cardiorespiratory capacity may result in misleading interpretation of distance run test scores.

PMID: 723510 [PubMed - indexed for MEDLINE]

"2.7 sec per mile per pound"

I've always see this type of calculation in regard to weight loss, but is it for a single mile or a 10k?