Weight and Climbing: Optimizing Body Composition for Climbing Performance
Josh Dreher had not climbed V11 since he was 19. He had written it off as something he would never do again.
In 2015 and 2016 he climbed thirty boulders V10 and harder, two of which were V12. He had never climbed this grade before. So how did he do it?
Josh attributes his success 40% to training and 60% to losing weight. Josh lost forty pounds over the course of a year and after this he was crushing.
to hear more about Josh’s Story, check out episode 70 of The TrainingBeta Podcast.
Body Composition Matters
The subject is taboo, but the truth is that your weight as a climber actually matters.
Have you ever climbed with a weight vest? I have. Strapping dead weight to your body makes climbing much more difficult. To illustrate this point: typically in an endurance session I can climb 45+ minutes on sustained 5.10. When I try to perform endurance workouts with a twelve pound weight vest on, at about 10 minutes I have to start backing off and climbing 5.9. After about 25 minutes of climbing routes I am completely pumped out of my mind. For reference twelves pounds is me climbing at roughly 109% of my body weight. It seems to cut my performance almost in half, especially in terms of endurance. Weight matters.
Whether you like it or not, your body composition has an effect on your climbing performance. There is a reason that The Rock Climber’s Training Manual has an entire chapter titled “Weight Management”.

What is the strength to weight ratio?
In terms of athletics, the strength to weight ratio is the amount of power (total force exerted in a unit of time) vs. an individual’s body weight.
Let’s look at an example of two individuals performing a deadlift.

Obviously, Person B can lift much more than Person A. However, Person A has a strength (or power) to weight ratio that is 16% higher than that of Person B.
Proportionally, Person B can do more with less.
How does the strength to weight ratio relate to rock climbing?
Looking at elite gymnasts, fighters, runners, and rock climbers, there are not many that are storing excess amounts of useless tissue.
Sensibly, the following can be derived:
Whatever is making up a climber’s body composition, it had better be useful.
What factors should be considered when trying to determine optimal performance weight for climbing?
A Climber’s Body Composition:
Three Factors to Optimize
- Sport-Specific Muscle Mass
- Body Fat
- General Health and Well-being
It is easy to conceptualize the optimal weight for climbing performance. You need to have just enough of the right kind of muscle to be very strong. You need to have low enough body fat that you are not hauling unnecessary weight up the wall, but you need enough body fat that you are happy and healthy and you have the energy to train and climb and enjoy your life.
Easy to describe, difficult to execute.
Sport Specific Muscle Mass
Your muscles are the strength portion of the strength to weight ratio equation.
“If you put on sport-specific muscle, your percentage gain in strength and endurance way outweighs the weight gain.” – 5.14 climber, coach and yoga teacher, Alli Rainey speaking from experience on Episode 5 of the Power Company Podcast.
There was a time that I weighed 119 lbs and could not do a single pull-up. I was light and thin, but not very strong.
Today I am the heaviest I have ever been in my life. I am also climbing stronger than ever and lifting heavier as well. In the past year ,the number on the scale has been slowly crawling up. Weighing roughly 8-10 pounds more than what used to be my “normal” weight was a little jarring at first. However, I now consider it a bit of a triumph. Additionally, all of my clothes still fit just fine, so I know I am not headed in the wrong direction of weight gain.
Alli Rainey’s exuberant proclamation at the end of the aforementioned podcast sums it up nicely,
“I don’t really care what I weigh because I can do these moves that I couldn’t do last year. That’s all that I care about!”
So go ahead, pack on some useful muscle. Everyone’s body works differently so your rate of hypertrophy won’t be the same as your friends, or your girlfriend or your boyfriend. Gaining Sport Specific Muscle Mass is key.
What about legs?
Note that in general climbers do not require the same legs that a competitive Alpine Ski Racer might require. If you have really beefy thighs, you might want to see if your climbing improves if you can decrease the muscle mass in your legs.
For further reading about “the benefits skinny legs” check out this article by the Anderson Brothers, the authors of the Rock Climber’s Training Manual.
Decreasing body fat
Body fat is another factor that you can optimize for climbing performance. As stated before, the perfect amount of body fat is the lowest amount at which you are still energetic, comfortable, and you are not overly sluggish.
If you are lean to the point of chronic exhaustion, you will not be climbing at your best. Our bodies need fat to survive, so advisably we do not want to decrease body fat to the point of risking health–mentally, emotionally, and physically.
This is a sport. Don’t lose your mind over getting to a specific send weight.
What the Data Says
Thankfully for us, the Tom Randall and Ollie Torr over at lattice training have collected some and analyzed some interesting data from 183 female climbers and 124 male climbers. All of the climbers whose data were collected ranked in the top 100 of routes/boulders in the world. The results? The average body mass index (BMI) for female elite climbers was 19.3 and that of men was 21.1. The healthy BMI range for both men and women is 18.5-24.9. Between 25-30 on the BMI index you are considered overweight. Over 30 you are considered obese.
As you can see the world’s most elite climbers lie at the low end of the healthy BMI range. This information is interesting but should be taken with a grain of salt. BMI is a useful indicator, but it is not a complete view of one’s body composition and should be treated as such.
Although this is a relatively small data set and I am only drawing correlations, it does say something to me that the best of the best are very lean. With this, I deduct that being very lean is helpful when climbing at a high level.
3 ways to gauge your body composition
While on the road to optimizing weight for climbing performance, it is important to determine where you stand. Here are three common ways to measure your body composition. I will go in ascending order of crudeness: the least helpful way being a scale and the most helpful being a formal body composition measurement.
Hop on the scale
The most simple metric one can use to measure their body is to hop on the scale. If you have measured your weight in the past, you can check your weight now and mentally compare where you are now vs. the past.
Your weight is easy to track and it can give you an idea about whether or not any changes to diet and exercise are working, but there are a few reasons the scale can be misleading.
- Weight can fluctuate exceptionally throughout the day. I am a 5’4″ female typically weighing in between 120lbs and 130lbs and I have seen my weight fluctuate up to 8 lbs in a day depending on activity, water consumption, etc.
- Muscle is more dense than fat. Therefore, if you are attempting to change your body composition and you are participating in any sort of resistance training program, you may be simultaneously losing inches off of thighs, arms, etc. while maintaining or even gaining weight.
The scale just doesn’t tell the whole story, so it is not a preferable measurement device for determing exactly where you are on the path to your optimal climbing performance weight.
Body Mass Index (BMI)
Apart from weight, the next best indicator of body composition is Body Mass Index (or BMI). BMI is a ratio of height to weight and is does not account for muscle mass vs. body fat. However, BMI does offer a rough architecture for determining an amount of weight you can safely lose, if you need to lose any at all.
Example: Alex Puccio’s Optimal Performance BMI
If you are not familiar with professional climber and decorated competitor Alex Puccio, give her a google. She is 5’2″ and beyond jacked. In her interview on The TrainingBeta Podcast, she describes her ideal competitive weight as being 114. At this weight, Alex has a BMI of 20.8. This is within the range that is considered healthy. However, this weight is hard for her to achieve and requires mindful changes to diet. Based on the this, it appears Puccio has determined her ideal performance weight.
Body Fat Percentage
The best way to determine where you are in terms of your body composition for climbing performance is pay for a service to determine this data. The main options for services are the Dexa Scan, the BodPod scan and the Underwater method. Calipers are also an option although they are not as accurate.
For more information best-selling author, Tim Ferriss, has a wonderful list of resources on his website outlining the different methods of acquiring body fat composition measurements.
Analyzing Body Composition Readings
Getting an actual reading of your body fat percentage is very helpful. Let’s take a look a scan I had taken in June of 2017 right before heading on a climbing trip to Spain.
Fat: 16.9 %
Fat Free Mass: 83.1%
Fat Mass: 20.4 Lbs.
Fat Free Mass: 99.9 Lbs.
Body Mass: 120.4 Lbs.
BMI: 20.7
I would say this is decent send shape, but not perfect. I could have lost five more pounds of fat, been in better shape, and stayed within the healthy BMI range at a 19.8.
Having this type of data is very useful. It prevents you from making incorrect assumptions such as, “The weight I gained over this training season is all muscle.” If you have two readings from the beginning and end of a three month period, you will be able to tell if this is true or not.
Additionally, specifically tracking muscle mass–even on an annual basis, is very interesting. Have you gained muscle in the past year? Have you gained strength without gaining muscle? These are all interesting and useful metrics to know.
Weight Optimization throughout the Training Season
I love sweets. I have a terrible sweet tooth. I literally could not upkeep the dietary habits that I would need to in order to stay at my optimal send weight year round. It would suck way too much and be a total waste of my mental energy. Additionally, Toblerone is delicious and so is beer.

In the winter time during ski season when I can’t really climb outside and I am trying to gain strength, I am a little more relaxed on the diet front. Then as Spring approaches I start becoming more mindful of my diet. Additionally, no matter what the summer months throw at me (AKA casual poolside drinking if I’m being totally honest), I do my best to have slimmed down by the fall for the second season of decent climbing.
Relaxing your diet is to your advantage for many reasons, apart from the fact that most of us enjoy eating some junk from time to time. Gaining muscle mass is difficult when you are in a caloric deficit. In a season of relaxing your diet you train at a heavier weight which will inherently make your fingers stronger as well. When you cut weight for a performance period your power to weight ratio increases and your odds of pushing your limits certainly increase as well.
It takes experimentation, but it is useful to determine your general training weight and optimal performance weight. With this knowledge, you can swiftly cycle through these biological markers as needed for your climbing objectives: training or performance.
You Can’t Ignore Your Weight
Like it or not, weight is a factor or climbing performance. If you are trying to send your hardest route to date this season and you somehow packed on 15lbs of fat in the last year, this will impact your performance.
Controlling your bodyweight is a tool that you can use to improve your climbing. Accept it, experiment with it, and be mindful of its power.Â
What about you? Have you ever experienced gains in your climbing from losing weight? Do you know what your ideal “fighting weight is”? Have you noticed your weight increasing from gaining muscle? I’d love you to hear your experience. Drop a comment below or shoot me an email. I am interested to hear your experience with observing body composition and climbing performance!
Hey Senderella!
So happy to hear you reference a DEXA scan. Most people have never heard of it. Some people understand that calipers aren’t that accurate, but few people understand that the water dunk test isn’t particularly accurate either. It assumes a bone density, and can vary quite a bit if you have high or low density bones. The DEXA is definitely the gold standard.
Great article too! I love that you touch on life balance. Losing weight is definitely helpful, but when your body fat gets too low, and it can definitely wreak havoc on energy, mood, hormones,… All sorts of stuff!
BMI is an interesting thing too. It’s really pretty useless for most applications. It tells you nothing about health, strength, fitness, or ability. It’s a completely useless ratio. But climbing might be one one of the few areas where being aware of it is interesting. All top climbers seem to sit in a similar place. This has nothing to do with their health or strength, but is more a sign of what a good weight for your given height might be.
Despite living around 10% body fat, my BMI still comes in as solidly high. I’ve played with lower body fat percentages, but they’re hard to maintain, and personally mess with my head. For me, losing weight means losing muscle mass and / or bone density. And neither is something I’m really after. Unfortunately, I’m not willing to sacrifice structural integrity (bone density). Which means I’m stuck with the Sisiphusian task of building strength without building muscle. Cest la vi!
I deal with similar issues in cycling. It’s hard to explain to the average person and even some cyclists why Im trying to lose weight. At between 9 and 16% body fat (because what is accuracy amirite?), and being visibly lean, it doesn’t make sense to most people! We want to excel at our sports, so it takes abnormal measures. However, it’s a much larger issue is climbing than cycling, because there are actually advantages to weighing more in some instances, even if that weight is fat. For example windy conditions or downhill. In the end, it’s always about maximizing your ability to “win”, whatever that is.
This year when my focus switched to the gym more than the climbing gym, I noticed that the weight gain definitely hurt the climbing. Things that would have been easy became difficult and things that I could follow friends up with a struggle became not possible with the extra 15 lbs. My weakness climbing is always group strength, then technique. That being said body fat percentage did the same, it was just the specific muscles that got bigger that made the difference. curious to see as I switch over to a more cardio balance and keep climbing if that makes a difference. I do need to focus on keeping climbing though, that’s always a struggle in the summer for me with few outdoor opportunities for the sport where I live.
Great article. I really appreciated your article, a lot of information about the body composition. Thanks for sharing your knowledge.
WOw!!!, amazing, this is exactly what i always to do
Thanks for the article, I have tried to investigate the role of both height and weight for rock climbing performance simultaneously using a statistical approach. This might be interesting for you. While being taller clearly seems to be a disadvantage when it comes to rock climbing, this seems to be entirely driven by the higher absolute weight of taller climbers.
See here
http://climbstat.blogspot.com/2018/12/being-tall-and-carrying-more-weight-are.html
That is interesting. Thank you for sharing. Have you compared your findings to those from Lattice training? It seems they have arrived at a different conclusion as far as height and climbers, citing that taller climbers can get away with lower finger strength and decreased economy of movement vs. their shorter counterparts.
The observations regarding really heavy and really light taller climbers is interesting as well. Perhaps if you are tall and too light, you lack power/muscle mass. Conversely, it is understandable that a heavier climber who is also tall is doubly disadvantaged due to the correlation between lower BMIs and climbing performance.
Do you think the results would be different in your examination if you observed only climbers who climb below 7a?