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The ideal weight for runners: One that allows you to run!

Focusing on an "ideal racing weight" could mean worse performance.


Despite my efforts to avoid a focus on weight loss, the reality is that most runners who care about their performance will, at some point, care about achieving their "ideal race weight."

There is no hiding that body weight correlates to running performance, but let’s be honest … what sport doesn’t have a correlation? Even on the opposite end of the sport spectrum, Olympic power lifters have a correlation between weight and performance!

Yet the running community is notorious for throwing around dangerous sayings like "2 seconds per mile faster, for each pound you shed" which makes runners of all levels, shapes, sizes, and ages attempt to drop weight before a big race.

Why is this dangerous, you ask?

Because it takes a runner’s focus away from running, and onto dieting. It takes a mental focus away from training and onto body criticism and self-sabotage. It takes a focus away from fueling and refueling, and onto restriction. This focus on weight loss is so detrimental to a runner because in the end:

Weight does not dictate performance. Training dictates performance.

Rapid weight loss, low body weight and lack of nutrition will ultimately stop training right in its tracks, therefore slowing a runners training progression. Rachel Schilkowsky, pro-runner for Rabbit, summed this up while slashing weight critics on the internet:

"I am approximately 10 pounds heavier than the woman that these cowards were criticizing. I may not be quite as fast as she is, but I dare say I train and race at a relatively high level. I’ve been running 90-100 miles a week for years now and, other than the occasional tight hamstring, I have been remarkably injury free. Since gaining 10lbs in 2016, I have had zero bone injuries. But in 2015, back when I was seriously underweight for my build, I did get a bone injury. A big one, in fact. A pelvic stress fracture. So it would appear that, despite the fact that I’m “carrying extra weight around”, I’m currently LESS likely to get injured. Why, might you ask? Because my body is nourished, healthy, and happy at this weight. And any slight increase in energy required to carry those additional 10 lbs is more than made up for by the fact that I’ve been able to put in strong, consistent training for years without injury."

- Rachel Schilkowsky, (1:15 half-marathon and 2:41 marathoner) @Rachelandherlaces Instagram post March 27, 2019.

As is the case for most life-long and professional runners, the ability to sustain a running career depends on years of training. When people focus on achieving a low racing weight, they deprive their body of essential nutrients, vitamins, and minerals. But most importantly, they deprive themselves of calories needed to sustain such a high energy output.

The International Olympic Committee has coined the term "Relative Energy Deficiency in Sport" or (RED-S) to describe the extensive physiological, metabolic, and hormonal consequences of not eating enough while participating in sport. Signs and symptoms, which can be noticed early by athletes, peers, coaches or parents, include irritability, decreased training response, and fatigue.

If these issues are not addressed, the body shuts down essential processes like bone building and repair, tendon strengthening, and the creation of enzymes and antibodies. The result: stress fractures, bone breaks, ligament tears, digestive issues, hormonal imbalances, weakened immune system, sickness and more.

These injuries will take months, if not years to resolve. A setback in training that is far more detrimental than carrying a couple extra pounds. Needless to say, in these instances, low body weight on runners certainly does not lead to improved performance.

I like focusing on the word "relative" in "Relative Energy Deficiency in Sport" because it highlights why runners do not fit into the traditional calorie-counting formulas and ideal racing weight ranges found on nutrition apps or health websites. What your body needs, and what weight you perform best at, is all relative to what you are physically demanding from it, day in and day out. And that is all relative to your body, your sport, and your training cycle. There is no way that a st