Here are a couple of resources:

http://www.mcmillanrunning.com/Running%20University/Article%201/mcmillanrunningcalculator.htm[/URL" target="_blank">

http://www.runningforfitness.org/calc/weighteffect.php[/URL" target="_blank">

Based on these, here are some facts. Tthe mcmillan calculator predicts a 4:11.15 marathon based on your HM time. That is 9:36 pace.

You can also expect to gain 2 secs/mile/pound lost. Losing 20 pounds should get you down to 8:56 pace.

You will have to get down to 8:36 pace to finish in 3:45. That will be tough but good luck.

Charlie

With identical fitness (whatever that means!) weight loss will
get you measured improvement. However, certainly as Nobby
has alluded, weight loss alone is not a substitute for improving
your running fitness, one way or the other. For example, if you
lack endurance, weight loss is not going to fix that problem.
If you lack strength or speed, it won't fix that problem either.

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quote:<HR>Originally posted by tigger:
If Nobby is still looking maybe he can speak to the Tokyo course. I looked on the website but could not find an elevation map.<HR>

I thought I saw the elevation map somewhere this year's race. I remember Amby (Burfoot) asked me about the course and the race in general because someone he knew was running and I thought I got the course elevation for him??? It's a different course from Tokyo Women's Marathon which is known for its hill around 32k (and downhill in the beginning). My understanding, and I will check and get back to you later, is that it's pretty flat but lots of turns. Goes through most of touristy areas. I have the video of this year's race and remember Jenga was heading for famous Asakusa gate at around 35k. Freezing rain. Wasn't a great condition this year. Should be fun though. I you want, maybe I can check with my buddies there to help you out or something. Problem is; my friends who live in Tokyo are not the one who care about running. I know one or two who can speak English... My American friend who runs lives in Nagoya, which is about 2 hours from Tokyo; but who knows, if there's enough incentive, he might come and watch (or run???) the race!

quote:<HR>Originally posted by jeneureka:
I also applied to run the tokyo marathon.

Nobby, where in nagoya does your friend live? are they a runner too? i live 15 minutes from nagoya and am always looking for running friends!<HR>

I thought I saw someone saying he lived in Japan--it might have been you??? My friend's name is John and he lives in Anjo and teaches English. Yes, he's a runner and runs 10k up to 30k (Nagoya City 30k). Originally from San Francisco. A great guy.

quote:<HR>Originally posted by leitnerj:
With identical fitness (whatever that means!) weight loss will
get you measured improvement. However, certainly as Nobby
has alluded, weight loss alone is not a substitute for improving
your running fitness, one way or the other. For example, if you
lack endurance, weight loss is not going to fix that problem.
If you lack strength or speed, it won't fix that problem either.

<HR>

I have to agree with everything you said in fact it is not disputable. Running performance requires a lot of physiological development and weight loss is mainly a side effect of some of that. However, with respect to getting the training done and maintaining performance it is a lot easier for runners who or at a health body weight. Additionally, running performance and more so distance running is all about economy. This passage by Frank Horwill from the Serpentine website says it best.

"No man six feet tall and weighing 176lbs (79.8kg) will ever win the London Marathon, and it is unlikely that a woman five feet six inches in height and weighing 130lbs (58.9kg) will ever do so either. Why? To answer this we must consult Dr Stillman's height/weight ratio table. He fixes the non-active man's average weight for height with a simple formula. He allocates 110lbs (56.2kg) for the first five feet (1.524m) in height and 5 1/2lbs (2.296kg) for every inch (0.025m) thereafter. He is harsher with women, giving them 100lbs (45.3kg) for the first five feet and 5lbs (2.268kg) for every inch above this.
Having established the average, he then speculates on the ideal weight for athletic performance, as follows:

Sprinters (100-400m): 2½ per cent lighter than average (6ft/176lbs - 2½% = 4lbs)

Hurdlers (100-400m): 6 per cent lighter (or 9lbs)

Middle-distance runners (800m - 10K): 12 per cent lighter (or 19lbs)

Long-distance runners (10 miles onwards): 15 per cent lighter (or 25½lbs)
Matching the figures to reality
How do these figures compare to past record holders? Here is a list of some of them:

Emile Zatopek - 5'81/2' (1.740m)/154lbs (69.8kg): same as the average man

Herb Elliott - 5'101/2' (1.791m)/147lbs (66.6kg): 11 per cent below average

Kip Keino - 5'9' (1.753m)/146lbs (66.2kg): 9 per cent below average

Seb Coe - 5'10' (1.778m)/120lbs (54.4kg): over 20 per cent below average

Steve Cram - 6'11/2' (1.867m)/153lbs (69kg): 15 per cent below average

Linford Christie - 6'21/2' (1.89m)/170lbs (77kg): 10 per cent below average

Wendy Sly - 5'51/2' (1.66m)/113lbs (51kg): 11 per cent below average

Yvonne Murray - 5'7' (1.70m)/111lbs (50kg): 18 per cent below average

Sally Gunnell - 5'6' (1.67m)/124lbs (56kg): 5 per cent below average

Ingrid Kristiansen - 5'61/2' (1.68m)/128lbs (58kg): 4 per cent below average

Tatyana Kazankina - 5'31/2' (1.61m)/110lbs (49kg): 6 per cent below average

Greta Waitz - 5'61/2' (1.689m)/110lbs (49kg): 17 per cent below average
There are one or two anomalies in these figures. For instance, Zatopek, who gained three gold medals in the 1952 Olympics (5km, 10km and marathon) weighs the same as the average man of his height. And Ingrid Kristiansen, who ran a marathon in 2:21.6, is just below the average weight for her height. However, note the staggering percentage below the normal for Seb Coe, who broke 12 world records in four years. If we take the average of these 12 world-class athletes, they weigh 10 per cent less than the average person of their height. So we must conclude from this that Drs Sheehan and Stillman had a point to make of considerable importance."

My view is if you are going to take up running as a hobby, for the sake of both performance and longevity shed those extra pounds.

quote:<HR>Originally posted by aharmer:
I'm a big fan of Daniels' principles so here's what he says. Your 4:28 marathon gives you a VDOT rating of about 33. He also has a calculator that tells you ow much your VDOT rating moves with weight loss or gain. This is based on a healthy weight loss of course. You are currently at about 190 lbs, which moves your VDOT to 35.6 which moves your marathon time to about 4:13. This is not figuring in improved fitness levels, just the weight you're carrying. If you are able to get down to 180 lbs for the race your VDOT moves to 37.6, which puts your marathon time at 4:02-4:03.

Assuming you can get down to 180 lbs you'll still need to find 15-20 minutes through improved fitness. If you're a new runner that's very possible, depends on your training methods. If you had any race times at the new weight it would tell us if your fitness level had advanced beyond the weight-loss-only improvement.

<HR>

Here's my take on these kind of calculations. As most of you know, these scientific researches always go; "everythng else being equal..." Here's a guy who's actively involved in marathon training; he would like to lose some more weight so, hopefully, he'd get faster. And all of us throw him some figures and formulas and all... There are basically two ways for him to lose weight; train harder (more) or eat less. If you train more, and hopefully he'd do it the right way, he'd improve anyways so his improvement will NOT be just from weight loss. And in this case, all things are not going to be equal. If he tries to lose weight by eating less and eating less alone (assuming he'd been eating right and not munching chips in the middle of the night, watching "friends" or "That 70s Show"), most likely, he'd get himself in a stress situation because he's not getting enough energy and, at worst, he'd get injured. Weight loss should come as a result of training; shouldn't be a target.

Concentrate on training right. If you have the "excess" weight, training will take care of it eventually. It may or may not be as quickly as you'd like; butanything else will not going to be as desireable as it otherwise would.

http://This message has been edited by Nobby (edited Jul-26-2007).

Nobby

I understand what you are saying. But we can all remember in school around XC time that for the most part the fat kids always bring up the back of the pack.