Ideal Race Weight for Runners

By: Andrew Jagim

How to identify an ideal race weight?

There is a lot of controversy surrounding the topic of identifying an ideal race weight for endurance athletes.  A lot of people believe that the lighter you are, the less weight you have to carry, which should then translate to being faster and improving overall endurance. However, there are also concerns with being too small and weak or losing too much weight and "running" (get it?) the risk becoming injured, specifically having an increased risk of stress fractures or hormonal dysfunction. However, the latter might be more a result of improper training tactics utilized to get down to a lighter weight (i.e. high training volume paired with an insufficient nutrition program.

You may still be wondering then what the ideal race weight actually is? I'm sure you can guess my response but I'll say it anyway... it usually depends on the person. First and foremost, I like using body fat percent rather than strictly body weight when working with an endurance athlete.  With that being said, elite runners usually have a body fat % ranging from 7-14% based upon gender.  This seems to be the range in which athletes perform at their best and have the optimal combination of minimal body fat paired with an adequate amount of lean muscle to maintain power output and endurance while at the same time not risking any injuries.  If you are curious about what your body fat percentage is, seek out your local exercise science department at a University in your area or a bigger commercial fitness center that may have the proper equipment to get an accurate reading.

When is the best time?

Typically, major changes in training adaptations, whether it be improved endurance, power, strength, or body composition are usually addressed during the off-season so as not to interfere with competitions or the rigors of a competitive season. 

However, for a lot of runners or cyclists this is also the time for a lot of high volume training (i.e. 80-120 miles a week for runners and 200-300 miles for cyclists) which creates a bit of a problem. Generally speaking, any reduction in body weight or body fat typically requires a caloric deficit. This means that an athlete would have to intentionally under eat during training in order to elicit the desired drop in body weight which subsequently may interfere with the athlete's ability to recover and maintain fuel supplies needed for the higher training volume. Can it be done? Yes. Is it easy? Hell no.  For example, I had a local cross country runner approach me at the end of Spring asking if I could help him lose a few pounds and more importantly drop his body fat percent prior to his upcoming season this fall. He explained that he was currently running about 70 miles a week and would be increasing it up to ~90-100 miles towards the end of the summer. So, we did some baseline testing and mapped out a nutritional program that was designed to slowly reduce body fat while still allowing him to training at that high of a volume. Slowly but surely, each month we did follow up testing and his body fat % went down along with his body weight.

Fortunately, this did not come at the expense of any lean muscle; essentially meaning that he should now be lighter, with the same amount of strength, power and muscular endurance to help him in competition. The table at the right highlights the progress he made over the course of the summer with body weight and lean mass represented on the left y-axis and body fat % and body fat (lbs.) represented on the right y-axis.  He says he still feels good and is looking forward to the upcoming season.

Take Home Message:

Identifying your optimal race weight and/or body composition will likely take a bit of trial and error. If you are interested, I encourage you to get some body composition testing done and then monitor training quality, recovery status and race times as you compete or train at different weights to identify where you perform at your best. Again, it is a fine line between competing at a lighter and leaner weight versus running the risk of becoming injured or constantly feeling over-trained.