Ideal racing weight / BMI for runners

julie_emma1

Hello all! I am interested in hearing what other runners have found to be your ideal racing weight or BMI?

I started my weight-loss journey approx. 7 1/2 years ago (yeah it took me awhile to achieve my first goal haha), when I just wanted to lose weight in general and was not a runner. At that time, I was 155 lbs, and sort of just randomly decided that 125 lbs for me (5'4") sounded like a good weight.

In 2013, I finally achieved my original goal weight and recently started getting more serious about running. So now I am less concerned with just general weight-loss and am more interested in setting goals that maximize my running potential. Sooo I'm just wondering what others have found through their experience works best for them in terms of racing weight / BMI for running (10k to marathon distances)?

blackcloud13

Not sure about BMI - but when I went for a running assessment last year, they said that 8-10% was the ideal body fat %age for a male distance runner. May be different for female runner, though (most likely more)

davemunger

According to "The New Rules of Marathon and Half Marathon Nutrition", ideal racing weight is the low end of the "healthy" range. "Healthy" is 18.5 to 24.9 BMI, so BMI around 20 would be pretty good. But that really depends on body type. For me a BMI of 20 would entail getting down to 156 pounds and I'm pretty sure that's not going to happen. I am quite thin when I weigh around 175 -- I don't know how I could lose another 20 pounds!

That said, when I do manage to get close to 175 (which doesn't happen often) I definitely can tell that running faster is a lot easier!

I had my body fat measured when I weighed about 185 and it was 15 percent. That means if I only lost fat and got down to 165 pounds I would be 4% body fat. I'd actually have to lose muscle to hit 156 pounds.

_Josee_

I've read that for a female body fat should be around 15-16% ...

I'm 5'6 130 lbs and around 19% body fat... My trainer estimated that without losing muscles I should weight around 120-122 lbs at 15% body fat.

I'm trying to get there but I'm having a really hard time with eating enough to fuel my runs + weight lifting and getting a deficit in. I was so much easier when all I wanted was lose weight!! (I was 188 lbs when I started this !)

Good luck! (And I'm looking forward to the answers you'll get!)

rduhlir

This is actually good info....I am starting to look into information on this as well.

KateRunsColorado

Good question...I will also be following this.

I've gotten down to 125 (5'-6"), and that's where I felt best so far. I'm now back around 130 just from not eating very well lately, but definitely want to drop those 5 lbs again (hopefully getting rid of all the christmas treats will help!).

julie_emma1

According to "The New Rules of Marathon and Half Marathon Nutrition", ideal racing weight is the low end of the "healthy" range. "Healthy" is 18.5 to 24.9 BMI, so BMI around 20 would be pretty good. But that really depends on body type. For me a BMI of 20 would entail getting down to 156 pounds and I'm pretty sure that's not going to happen. I am quite thin when I weigh around 175 -- I don't know how I could lose another 20 pounds!

That said, when I do manage to get close to 175 (which doesn't happen often) I definitely can tell that running faster is a lot easier!

I had my body fat measured when I weighed about 185 and it was 15 percent. That means if I only lost fat and got down to 165 pounds I would be 4% body fat. I'd actually have to lose muscle to hit 156 pounds.

Thanks everyone for your feedback!

Dave - it sounds like according to "The New Rules of Marathon and Half Marathon Nutrition" my ideal racing weight would be around 116-118 (taking into account BMI only). But as you and others suggested, it sounds like it might be more important to think about body composition, not just weight...So a silly question for you! How and where did you determine your body fat %? Are the online calculators any good or do I need to go to a professional for this?

julie_emma1

Not sure about BMI - but when I went for a running assessment last year, they said that 8-10% was the ideal body fat %age for a male distance runner. May be different for female runner, though (most likely more)

Thanks for your input on this! Just curious - where did you go to do the "running assessment" and what did this entail, if you don't mind me asking?

mitchyinge

I used my scales (they said 24% shock horror) and the calipers (they said 13%, I love them, they are my best friends) and I split the difference and decided it was about 18% (am not very good with numbers so please don't laugh too hard if all this is wrong)

then I did matt fitzgerald's thing to calculate my lard mass eg if you are 120lbs with 18% body fat then: 120 x 0.18 = 21.6

subtract that from your whole weight to find lean mass of, for example, 98 lbs

decide on a target (he suggests for women aged 20-29 anything between 10 and 16%) then express that lean mass goal in decimal form - so for example if you aim for 11% body fat then 100-11 = 0.89

then divide current lean mass by goal percentage

eg: 98 divided by 0.89 = 110 lbs

and that would be your target weight

but when I did this I must have made a mistake as it took me almost back to my birth weight so am probably going to not aim for that just yet!

schmenge55

There are guidelines, as everybody else said, but every individual is different. A rough rule of thumb is that every pound of EXCESS fat (that you do not need as you certainty need fat) adds about 2" per mile to your pace. Hence dropping 10 EXCESS pounds of fat would drop your pace by 20" a mile. The best way to look at your composition is to get a DexaScan. It will tell you pretty close what your fat percentage is AND where that fat is. I have a pretty good body fat percentage for a male but it is also disproportionately in one area (diet related) so ideally I think that should go. Now ideally and doable may be different

According to "The New Rules of Marathon and Half Marathon Nutrition", ideal racing weight is the low end of the "healthy" range. "Healthy" is 18.5 to 24.9 BMI, so BMI around 20 would be pretty good. But that really depends on body type. For me a BMI of 20 would entail getting down to 156 pounds and I'm pretty sure that's not going to happen. I am quite thin when I weigh around 175 -- I don't know how I could lose another 20 pounds!

That said, when I do manage to get close to 175 (which doesn't happen often) I definitely can tell that running faster is a lot easier!

I had my body fat measured when I weighed about 185 and it was 15 percent. That means if I only lost fat and got down to 165 pounds I would be 4% body fat. I'd actually have to lose muscle to hit 156 pounds.

Thanks everyone for your feedback!

Dave - it sounds like according to "The New Rules of Marathon and Half Marathon Nutrition" my ideal racing weight would be around 116-118 (taking into account BMI only). But as you and others suggested, it sounds like it might be more important to think about body composition, not just weight...So a silly question for you! How and where did you determine your body fat %? Are the online calculators any good or do I need to go to a professional for this?

schmenge55

BTW, I also have a scale and I use that as a comparison against my scan. has a larger error rate week to week but close enough for government work

mitchyinge

this is a bit unhelpful of me but my running has felt much easier since I gained 3kg and I even started running a tinier bit faster (not as fast as you today though obviously!)

so am not sure how it all works

CarsonRuns

There are guidelines, as everybody else said, but every individual is different. A rough rule of thumb is that every pound of EXCESS fat (that you do not need as you certainty need fat) adds about 2" per mile to your pace. Hence dropping 10 EXCESS pounds of fat would drop your pace by 20" a mile. The best way to look at your composition is to get a DexaScan. It will tell you pretty close what your fat percentage is AND where that fat is. I have a pretty good body fat percentage for a male but it is also disproportionately in one area (diet related) so ideally I think that should go. Now ideally and doable may be different

This was tested in a lab by adding weight to runners to see how it impacted their overall pace (if I remember correctly). In the real world, 10 pounds doesn't translate directly to 20 seconds per mile. There are far too many other variable involved, like race distance, training load, course topology, etc.

My personal experience doesn't play out to 20 seconds per mile either. I ran a HM at 120 pounds in the Spring of 2012. I ran a PR there, but not 20 seconds per mile faster than my previous 130 pound HM. Yes, I had less body weight to haul around, but the gains were from the mileage that I put in primarily. Weighing less just helped out a teeny bit.

mlogantra76

I've been thinking about this lately. I know when I was at the absolute lowest healthy weight for my height, I got accused of having an eating disorder. And due to my shape(pear), I was told my upper half looked skeletal. I also didn't feel my best and somewhat agree that it didn't look healthy on me. I was doing a lot of running back then too but didn't run any races and have no idea what my pace was. So, for me personally, my plan is to go from the upper range for my height to the middle range and see what that does to my pace. I also want a weight that I can maintain.

schmenge55

not sure how the testing was done but regardless I agree with your statements. Although I will never see 120 pounds. It is a very rough rule and there are dozens of variables. Just like calculating max heart rate with a chart. Actually I guess that is worse than rough

There are guidelines, as everybody else said, but every individual is different. A rough rule of thumb is that every pound of EXCESS fat (that you do not need as you certainty need fat) adds about 2" per mile to your pace. Hence dropping 10 EXCESS pounds of fat would drop your pace by 20" a mile. The best way to look at your composition is to get a DexaScan. It will tell you pretty close what your fat percentage is AND where that fat is. I have a pretty good body fat percentage for a male but it is also disproportionately in one area (diet related) so ideally I think that should go. Now ideally and doable may be different

This was tested in a lab by adding weight to runners to see how it impacted their overall pace (if I remember correctly). In the real world, 10 pounds doesn't translate directly to 20 seconds per mile. There are far too many other variable involved, like race distance, training load, course topology, etc.

My personal experience doesn't play out to 20 seconds per mile either. I ran a HM at 120 pounds in the Spring of 2012. I ran a PR there, but not 20 seconds per mile faster than my previous 130 pound HM. Yes, I had less body weight to haul around, but the gains were from the mileage that I put in primarily. Weighing less just helped out a teeny bit.

davemunger

Thanks everyone for your feedback!

Dave - it sounds like according to "The New Rules of Marathon and Half Marathon Nutrition" my ideal racing weight would be around 116-118 (taking into account BMI only). But as you and others suggested, it sounds like it might be more important to think about body composition, not just weight...So a silly question for you! How and where did you determine your body fat %? Are the online calculators any good or do I need to go to a professional for this?

The online calculators are pretty much worthless. Calipers are okay if they are administered by a well-trained person, but by far the most accurate are immersion methods -- either getting immersed in water or in a "bodpod" which does the same thing using air. Basically what is happening is that your body's volume is being measured -- from that your density can be determined and a calculation made to give body fat percentage.

I think there are some places that will do this for a fee, but I got mine done at a local research institution because I participated in a study on running, so in my case it was free.

jturnerx

My ideal weight is the one where I can be healthy. I'm 5'0". When my weight has dropped to around 110 or thereabouts I lose my period. This has happened consistently and that's the sort of health Russian roulette I don't feel particular keen on playing. So I keep my weight around 115, I have a regular period and I can easily stay there without getting neurotic about food.

ohhayitskk

I'm 5'3 and currently around 130 pounds. I find that when I weigh around 125, it's much easier for me to maintain a sub 8 minute mile pace in most shorter races (5k, 10k, etc). I ran my 10K PR when I was probably around 115-120, but that was five years ago and I didn't pay much attention to my running back then. I'm curious to see where I would be if I weighed 115-120 again with all the running work I've put in over the past three or four years. Because of my build, 115 is on the skinny side for me, but I'd like to get down to 120 for racing purposes over the next several months.

That being said, I just ran a 5K PR about a month ago at this weight, so who the hell even knows.

SonicDeathMonkey80

I went from 178 to 152, BMI of 26 to 22. I dunno if it was a huge factor, but losing nearly 20% of bodyweight has to count for something.

PeteWhoLikesToRunAlot

Good question - personally, I'd think it'd be the lowest you can be while keeping yourself healthy and fueled adequately, and able to train to the point that you're able to make gains in endurance/speed. I can tell you from experience that in some races, I've run a faster pace while weighing a couple more pounds (no more than 3 lbs), because I had done some solid training prior to the quicker race. While being lighter can't hurt, i think your overall fitness & training probably play a bigger part.

MinimalistShoeAddict

I offer no opinions other than what has already been stated above. You may however find this data of interest:

http://www.runnersworld.com/elite-runners/bmis-champions
http://www.runnersworld.com/womens-running/bmis-of-champions-womens-edition

Personally I pay more attention to my body fat percentage than BMI. That being said when comparing yourself to others (such as the Olympic gold medal winners above), BMI data is easier to track down for obvious reasons (it can be calculated solely based on height and weight data).