UKC

Lattice training have had a close look at BMI and climbing ability, and concluded that so long as your BMI is in the healthy 18.5 to 25 range, you should be able to climb at your hardest, and that getting your BMI lower than the healthy range is unlikely to enable harder climbing!

Nice, more cake please

Their grade numbers are explained in pt 2.

http://latticetraining.com/2017/10/04/bmi-and-climbing/

http://latticetraining.com/2017/10/04/bmi-in-elite-level-climbers/

http://latticetraining.com/2017/10/09/bmi-and-climbing-part-2-elite-climber...

http://latticetraining.com/2017/10/30/bmi-and-climbing-part-3-all-8a-nu-cli...

A linear regression for variables that follow very weird distributions? Amazing.

My BMI is something like 25.9 but I'm not fat at all. Genetics have allot to do with our body's natural inclination to a certain physique so I don't think BMI in climbing is a very useful metric.

r^2 of those correlations must be very close to 0.

My bmi last July (when I was at a stage I was aiming to be) was 26.1, and I was 11% bodyfat. But apparently 11% is overweight.

Bmi is a terrible measurement. 

If you are already fit and climbing at a decent level you know that BMI has absolute no correlation to performance. Likewise if you have weighed yourself at a fit state and calculated the upper and lower limit of a healthy BMI the range is so large as to provide any useful guidelines. (Ie. When I am bouldering f7a+ I weigh 60kg - the lower 'healthy' BMI limit would put me at 8kg lighter! I would be absolutely powerless and emaciated at that weight. Other negative effects would apply at the upper limit.) Look at the body composition of Ondra and how much more mass he has now compared to when he climbed Dura Dura. He is obviously has more mass and probably weighs more. Yet he is climbing as hard as ever if not harder.

Summary - yes, being 'light' matters if you want to climb hard. Does BMI mean squat? No.

I think what lattice are doing great but their studies on BMI are just nonsense.

You can’t diet to lose weight and train effectively. 

You either train and eat well, or you don’t train well, diet and lose weight. 

BMI is a statistical measure to keep track of populations. It has absolutely no use for individuals other than highlighting that their wieght is not in the ‘normal’ range. Once you identify someone is not in the normal range, you have to work out why. BMI has absolutely no use for athletes. 

I, personally, don’t agree with that statement.

My calorific maintenance is around 2,500calories a day (from a mixture of calculations and trial and error). However, when cutting fat I am in a calorific deficit of 300calories. I also train in the gym, and include cardio. Some days my deficit can be up to 1000calories, as I eat the same cardio or not. 

I find I can lift exactly the same, while in a deficit. Run further, because cardio and energy levels are increased. 

Clearly when in surplus, the increase in strength is quicker and more noticeable. But I wouldn’t say you cannot train and lose weight at the same time.

Just thought it was useful to see that it's not worth worrying about too, so long as you are in the healthy range, + perhaps the middle of that range is ideal.

Losing a few kg might help when serious about a long term project / comp, which might then put you at the lower end of the healthy scale for a short time.

That's not correct. As an example, I'm bottom end of the recommended BMI. If I put on 21 pounds I'd be mid range BMI. 21 pounds is a lot of extra weight to drag up a route especially an overhanging one (even half that is significant). I could put on 42 pounds and still be in the recommended range, but I doubt I'd get above the 2nd clip on some things I climb now. I don't think it's useful looking at BMI generally, but more at body fat. And the more of that you lose, down to the safe minimum, the better. I'll add that I don't think this makes so much difference on vertical or near-vertical stuff, but when it gets very overhanging and sustained it does.

I guess fat percentage would be a better indicator than BMI?

Over 2 years I managed to go from 22% fat to 14% fat and feel I still trained effectively during that time. I'm currently at 15.5% and hoping to get to 10%, but it does get harder as you age (49 and counting). 

Most of the climbers that climb harder grades than me are leaner, and some considerably so. My finger strength and technique are pretty good, and I am working on my body strength, but I have no doubt that fat percentage is a big part of the equation for me.

I would like to see a study of fat percentage and climbing grade?

Bit harsh.  I'm sure it's very useful as a statistical tool to look at large groups of people, populations, that sort of thing.  It's only when you try to use it to tell you something about an individual that it's rubbish.

Which is how it is used by the NHS, occupational health teams in most public services and many other places. Strict BMI cutoffs are used because it's easier and cheaper than treating people as individual genetic entities. 

What was quite heartening was that you can have a relatively high BMI and still boulder high into the grades. You would have to assume the weight was being driven by muscle mass rather than fat mass (unless they surveyed a retired John Dunn?) The general noise and scatter observed at mid to lower grades may be missing due to lack of people surveyed operating in the higher spectrum.

It is quite interesting to see that a significant portion of female elite climbers are in the unhealthy BMI category. To give some context this would mean a 5’2” women would need to weigh less than 47.5kg (assumed age of 23yrs). Unhealthy female BMI category may lack nuance, so maybe splitting out height, age, weight, muscle and fat mass separately maybe useful.

So if I buy some decent scales, which only cost around £30, my weight and my % body would be the 2 things worth watching. I can't remember now, but 6 months ago looked at a few from Argos, and think even 1 set claimed to measure muscle mass or %.

Measuring body fat percentages is notoriously hard, unless you have access to a DEXA scanner and a tame radiologist. With the scales, which measure the impedence of your body, you can get a rough idea of which direction your body composition is moving (try to take measurements at the same time each day, maintain a consistent level of hydration, and calculate a rolling average), but think of it as a relative value, as it could be miles from your actual body fat percentage.

Ciro is correct, bathroom scales even on expensive models have poor accuracy compared to DEXA or similar imaging technology.  The best method is to average a weeks daily recordings and compare week on week in the hope that the inaccuracy level is always the same.

Right yep, even 2 different makes claiming 50g accuracy didn't know if I had my sox n harness ( new word for undies) on.

They would give the same weight for just in my baby suit, and same with my kit on. Took them back.

The data does not compare onsight grades. I suspect there is a vastly bigger difference there - and that getting lighter will change your onsight grades markedly. Would be interesting if they tested that.

It's difficult to be objective, but if you can do without putting a number on it a good look in the mirror is as effective a way of getting an idea how much fat you're carrying as any.

Another easy way to get a rough idea of a number is the so called 'American military' method, which only needs a tape measure - you just compare the circumference of your waist with your neck, for men, waist, hips and neck for women.  There are lots of calculators online to put the two (or three) measurements into, and get a percentage out the other end that's probably just as good as the number an electrical gizmo will give you.

+1

It's very easy to draw incorrect conclusions from this analysis (ignoring the statistical variation) say that "as long as your bmi is healthy then weight won't make a difference."  That would be 100% wrong. It makes a huge difference. To test this they would need to follow trends in performance vs weight change of individuals over a period of time.*

But what this tells us is that you don't need to be outside the nhs 'healthy' range in order to climb at an elite level. Given that most climbers have additional musculature vs a standard adult, (ie lower fat% for a given bmi) this isn't surprising.

*This would take quite a lot of effort to organise and time to play out, but it'd be really interesting. I'd be willing to support if anyone is listening.

I climb hardest when my BMI is at the bottom of the healthy range.

But I think we all know BMI is a bit misleading anyway.

Bmi is just a modern idea to jolt people who do absolutely nothing into getting off their butts. Once you start to factor those who exercise and difference muscle mass it is worthless. Look in the mirror, it doesn't lie.

Just done mine and it is 27.1 and I'm probably fitter now than I've been for a couple of years, training most days for some races through the year as well as bit of physical graft most days.

I’m not convinced it is useless as a guide for individuals, we just have to understand it’s limitations and use it with other measures such as measuring body fat or just looking objectively in the mirror. Genetic differences will lead to some BMI differences, but 18-25 is a very wide range.

It is easy to come up with examples of sports people above and below the range, but a) most sports people competing at a decent level are within the range b) those outside of the range may be very well adapted to their sport, but that isn’t the same as healthy.

I think a lot of the people who claim BMI is rubbish, have their own agenda, even if that is just not admitting that they are as healthy as they think they are.

From my own perspective, most of my training is running focused. I currently have a BMI of around 23, I’m aiming to lose a little weight / fat over the next few months, as I know that will help me go faster, but I know that if I went under 20 I would be underweight / unhealthy.

Interesting that that this work is being done. In my opinion most of the plots show no correlation (or very weak at best) between BMI and grade at the group level. Some of the correlations seem to be biased/driven by outliers as well. It would be interesting, and I think more indicative of any causal relationship, to see a longitudinal study of how BMI vs grade varies in individuals.