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Ideal racing weight / BMI for runners

julie_emma1
julie_emma1 Posts: 146
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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)?
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Replies

  • blackcloud13
    blackcloud13 Posts: 654 Member
    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
    davemunger Posts: 1,139 Member
    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_
    _Josee_ Posts: 625 Member
    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
    rduhlir Posts: 3,550 Member
    This is actually good info....I am starting to look into information on this as well.
  • KateRunsColorado
    KateRunsColorado Posts: 407 Member
    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
    julie_emma1 Posts: 146
    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
    julie_emma1 Posts: 146
    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? :smile:
  • mitchyinge
    mitchyinge Posts: 196
    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
    schmenge55 Posts: 745 Member
    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
    schmenge55 Posts: 745 Member
    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
    mitchyinge Posts: 196
    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
    CarsonRuns Posts: 3,039 Member
    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
    mlogantra76 Posts: 334 Member
    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
    schmenge55 Posts: 745 Member
    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
    davemunger Posts: 1,139 Member

    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
    jturnerx Posts: 325 Member
    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
    ohhayitskk Posts: 6 Member
    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
    SonicDeathMonkey80 Posts: 4,489 Member
    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
    PeteWhoLikesToRunAlot Posts: 596 Member
    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
    MinimalistShoeAddict Posts: 1,946 Member
    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).

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  • julie_emma1
    julie_emma1 Posts: 146
    Thank you everyone for your input on this. Thinking about your replies, it sounds like I should try to figure out my body fat %. I currently have a bmi of 21.4, but I really have no idea how much of that is lean mass and how much is "excess fat"...

    That being said, it also sounds like proper training and increasing mileage are probably going to have a much more significant impact on my running performance than weight loss per se (especially at my level). So I'll try to focus on that, rather than fiscating on the scale so much :)
  • julie_emma1
    julie_emma1 Posts: 146
    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
    Thanks for the links - very interesting to see the comparison across sports!
  • DavidMartinez2
    DavidMartinez2 Posts: 840 Member
    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!

    I used the tables in the back of his book to set a goal BF%, worked out well for me. Good reading if you are looking to expand your knowledge of dietary requirements and why good food is important, bad if you are looking for a set in stone diet plan.
  • mitchyinge
    mitchyinge Posts: 196
    Good reading if you are looking to expand your knowledge of dietary requirements and why good food is important, bad if you are looking for a set in stone diet plan.

    Embarrassingly I think I would like a set in stone diet plan. Otherwise I just eat refried beans or pizza until I get somewhere near my daily calories (this might just be a winter/holiday/virus thing), yeah, I would benefit from a diet plan at the moment.
  • beeblebrox82
    beeblebrox82 Posts: 578 Member
    So i just got the calipers put on me and they told me I'm at 9% body fat. I had no idea I was down so low already. I was about to embark on a full court press fitness crusade lol.

    Curious what scales others are using and if they've fond them to be accurate... or at least, more accurate than my Tanita, which had me at 20% this morning.

    Now I'm suddenly concerned about having too LITTLE body fat. I'm 10 pounds heavier right now than I was in Fall during racing season last year, lord only knows what my percentage was then. Trying to figure out what my fitness goals should be at this point. :indifferent:
  • legallyblonde916
    legallyblonde916 Posts: 43 Member
    There is a book called "Racing Weight" by Matt Fitzgerald. Get it. :)
  • SillyC2
    SillyC2 Posts: 275 Member
    Thank you everyone for your input on this. Thinking about your replies, it sounds like I should try to figure out my body fat %. I currently have a bmi of 21.4, but I really have no idea how much of that is lean mass and how much is "excess fat"...

    That being said, it also sounds like proper training and increasing mileage are probably going to have a much more significant impact on my running performance than weight loss per se (especially at my level). So I'll try to focus on that, rather than fiscating on the scale so much :)

    So, I think there's something key hidden here. Can you train well at that "low" weight? Personally, when I've been scraping the bottom of the "healthy" BMI range, I've been prone to hypoglycemia and I get too sluggish to train well, or I skip runs that don't line up perfectly with my meals and snacks.

    Anecdotally (I'm an ultrarunner), the ladies and I seem to notice that the thinnest among us tend to get injured more often, and we've been wondering if the extra layer of fat is somehow helpful with recovery. But that could be coincidence.
  • blackcloud13
    blackcloud13 Posts: 654 Member
    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? :smile:

    Not at all.

    I went to an Asic shop (in London), where they

    - Weigh you and estimate body fat using some hi-tech looking machine
    - They then put you on a treadmill, put a mask on you to analyze your breathing, monitor your heart rate, and then make you run on a treadmill, slowly upping the pace (until you surrender or fall off!)
    - They also film your feet, looking for where your feet strike etc, as well as using sensors to check your arm swing etc
    - After all that, then test your leg strength (looking for left right balance).


    At the end of all that, they write up a report an give you tips. They also predict how long you'd take to run a half marathon and a marathon (they were scarily accurate with me on the marathon last year - within two minutes!)

    If you like I can send you some excerpts of their report
  • julie_emma1
    julie_emma1 Posts: 146
    So, I think there's something key hidden here. Can you train well at that "low" weight? Personally, when I've been scraping the bottom of the "healthy" BMI range, I've been prone to hypoglycemia and I get too sluggish to train well, or I skip runs that don't line up perfectly with my meals and snacks.

    Anecdotally (I'm an ultrarunner), the ladies and I seem to notice that the thinnest among us tend to get injured more often, and we've been wondering if the extra layer of fat is somehow helpful with recovery. But that could be coincidence.

    Interesting observation about low weight and increased rate of injury. I wonder if there is relating to differences in nutrition between the medium-weight and low-weight runners? I.e. More calories and protein to help with post-run healing...just a thought?

    For me personally, I definitely find that I can train better at my current weight than when I was heavier. When I had a BMI of 26.6 running felt impossible (but I was also very out of shape and ate cr@p). At BMI 24.0 running felt okay but I was still pretty sluggish. Now at BMI around 21-22 range I feel much more efficient and energetic on my feet. But I don't know, really, if that's because I've been running longer and have built up my weekly mileage, or if that is truly due to the weight loss itself.

    Either way, what I'm at right now seems to be good. Maybe I'd see improvements if I got down to BMI around 20.0 but maybe I'd start to get more hypoglycemic and/or injuries...so staying as is seems like a good plan for now at least :-)
  • blackNBUK
    blackNBUK Posts: 58 Member
    It strikes me as nicely ironic that the measure that almost everyone cares about, body fat percentage, is so difficult to get! As far as I can see all the ways of measuring body fat are some combination of expensive, impractical and inaccurate.

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