EFFECT OF LOSING WEIGHT ON RUNNING PACE

tunney wrote: »

Good article. I had been aiming for 145 lbs but based on that its 140lbs I should be looking at. Man that will be tough. Worth it though.

Last time I weighed myself I was about 19.8% lower than what that says is average. Groovy.

I've never looked at the men's weight/height/speed ratio's but if you look at the women, the world's fastest are all 10-25% less than the minimum weight considered necessary for health (and reproduction). It would appear from the research that there is a very real distinction between athletic performance and health at both ends of the scale (pun intended).

While I have no problems with the elite doing damage to their bodies in the persuit of excellence, I'm not sure we can recommend it to the average runner/triathlete who doesn't earn their living from sport.

One example of this is bone health. Elite marathoners tend to have weaker t-squared scores (a measure of bone density) than the general public. This is believed to be due to the conbination of lots of mileage and low body weights. At the other end of the scale, those people who never exercise also have lower bone density than the moderate person who excerises regularly (weight bearing) and maintains a healthy weight. There are similar results in gynaecological studies, rheumatology etc.

hunnymonster wrote: »

One example of this is bone health. Elite marathoners tend to have weaker t-squared scores (a measure of bone density) than the general public. This is believed to be due to the conbination of lots of mileage and low body weights.

So true. Sadly though, I'd say it's gotten to the stage where it's probably impossible to be an elite female distance athlete without being osteopoenic/porotic.

These people seem to take stress fractures for granted nowadays, it's seen as just a consequence of the necessary training rather than a sign of perhaps serious weight or nutritional deficiencies.

Maybe we should bring weight categories into running! Anyone up for lightweight, middleweight, heavyweight categories in the next BHAA race

cfitz wrote: »

Are there studies to show the problems that these top athletes (who are below what is considered the minimum healthy weight) suffer from? There are probably plenty of studies to show that people who are below their minimum 'healthy' weight are likely to suffer from x, y, and z. But I'd be interested to learn whether the risks are as high when you're in the kind of shape that the top athletes are in.

Because distance athletes have the combination of 'repetitive impact' (loads of miles) on their bones and often a restricted diet (through a desire to be as light as possible to maximise performance or through an eating disorder (I suppose that's a bit of a continuum), they may have more risk factors for osteoporosis (brittle bones) than a non-athlete who is on a restricted diet, all other things remaining equal. Added to this, the hormonal factor in females (and possible contraceptive complications*), mean that low bone density (osteopoenia and osteoporosis) are probably pretty widespread in female athletes. It is probably vastly underdiagnosed. Less intake of meat and calcium products is also sometimes prevalent in young women and may be a factor.

I know of a now retired international athlete who went to have her bone density checked and the staff doing the test wanted her to go in a wheelchair they were so terrified that the next step she took could lead to a hip fractue her score was so low:eek:. However, because of the possible combination of risk factors, recreational athletes may also be at risk -it is not just your elites who are vulnerable. Wimmin athletes, check your bone density!

*when docs are prescribing contraception it doesn't always come naturally to them to check if the person does a lot of exercise and if this may need to be considered...

At the same time impact loading of bones is necessary for healthy bones, there just needs to be a good balance of bony degeneration and regeneration, so don't assume loading or weight bearing exercise is bad!

Is anyone else surprised that Linford Christie was underweight? Granted he didn't have much fat, but he had so much muscle...

MCOS wrote: »

Rob Kearney smokes like a trooper :mad: yet he will face Rockokoko et al on Saturday.

:eek: Is smoking common amongst professional athletes? Am surprised by that.

@ Peckham - I suppose it's just the weight that I stabilise at when I'm running 50 miles a week consistently and eating healthily.* If I run 30 miles a week, I tend to be about 4-8lbs heavier. When at this 'race weight' I feel good, light but not weak, strong but not fatigued. My easy runs feel easy and I tend to race well. So I just assume that 'stabilised' weight is my race weight. I might have been a few pounds lighter for Ballycotton, and maybe the marathon, but I'm not sure, I didn't monitor it much this year, but will have to remember to check weight on race days in future to see if I have a more ideal 'race weight', in light of this thread.


* So I'm generally this weight most of the time now, but after holidays, Christmas, rest week (twice a year) I'll be up to half a stone heavier, might take about 3 weeks of training to stabilise again.

hunnymonster wrote: »

cfitz, the studies I was talking about were done on professional athlete's or college scholarship people (most of this stuff is done in the US). Underweight Jane Blogs have a whole lot of other problems.

I'm not sure I put my question across very well. Let's take bone density as an example. (I'm no doctor/scientist so this hopefully this example makes some sense.) Low bone density is something that makes you vulnerable to problems rather than being a problem itself. So my question is: If an athlete trains really hard and looks after herself, will other strengths gained from this make her less vulnerable to broken bones (despite her lower bone density) than someone who exercises 'moderately'?


-I'm not really that concerned about healthy weights for female athletes but I wouldn't like to think that I (a male athlete) would be significantly healthier at a higher weight.

cfitz wrote: »

Low bone density is something that makes you vulnerable to problems rather than being a problem itself. So my question is: If an athlete trains really hard and looks after herself, will other strengths gained from this make her less vulnerable to broken bones (despite her lower bone density) than someone who exercises 'moderately'?

The more you run, the more bone you'll break down. A good diet providing enough things like vitamin D and calcium etc. as well as having a good hormonal balance will facilitate regeneration of new bone. If an athlete looks after herself by ensuring she has the right diet etc. she will lessen the risk of bone damage due to all the impact from running, but she'll still be more at risk than someone who eats well and doesn't run as much. However, she'll probably have a healthier heart, cardiovascular system etc.

Osteoporosis is maybe a bad example, because while you need weight going through your bones to stimulate regeneration of bone (bone is constantly being turned over, ie broken down and regenerated regardless of whether you exercise or not), excessive impact, particularly repetitive cycles of this lead to increased breakdown of bone. With obese kids for example, they are getting more diabetes and othe such problems, but their bone density is improving - this is because they have more weight going though their bones. Similarly when Ian Thorpe was at his best there were stories that he was in the pool 14 hours a day (?exagerration) and their were concerns that he would get osteoporosis because he did not have ebough weight going through his bones due to the buoyancy effect of the water.

So distance running, IMO will generally make you healthier in nearly every way. But the repeated impact may be a risk factor for osteoporosis. Alone this may not an issue but combined with other risk factors, which unfortunately are common in (particularly female) athletes, might be enough to tip the scales and so stress fractures occur.

The female athlete triad is a recognised medical entity in female athletes - the combination of low weight, amennorhoea (lack of period) and eating disorder has been a major downfall for many top athletes.

I don't know if that answers the question, but no matter what, repeated loading leads to increased bony breakdown. Minimise this bony breakdwon by wearing supportive footwear, run on soft surfaces, or in the pool! Maximise regeneration by having a diet rich in calcium, and vit D and try to maintain correct hormonal balance. With this you are doing all you can, but the risk factor of repeated loading will still be there...