It is well known that climbing (both bouldering and sport climbing) is a sport that is affected by power to weight ratios. The biggest factor that bodyweight affects is the percentage of bodyweight that we’re able to hang on a climbing hold – simply put, if you reduce body fat and retain lean muscle mass you’ll be able to hang poorer holds for longer.

For this reason there are many who have tried to reduce bodyweight as a method for increasing performance. Whilst we are objective enough to acknowledge that this can work in certain situations our data suggests that long term low BMI does not necessarily result in the best climbing performances.

Below we have plotted the BMI against the max grade climbed in the preceding 2 years for every climber in our database.

While there is a slight negative correlation it is not substantial. Of greater note is that the line of best fit in all cases lies within the ‘healthy’ 18.5-24.9 range, this suggests that maintaining a low BMI is not necessary for climbing hard.

Note: this is a slightly expanded version of a facebook post.