Should Runners Lose Weight?

The New York Times recently published an article that has the running world talking. The article highlights Jen Miller, a woman who lost 25 pounds by switching from marathon style training to training focused on a 1-mile race. This included less volume, but more intensity and a good deal more lifting. Jen also changed her diet, but she did not, by any means, go on a diet. In fact, she cites bacon as one of the foods she ate on a regular basis.

I must concede that Jen’s story is an inspirational one. Furthermore, it hits home for many runners who are unsure of how much of a factor body weight is on performance.

With that in mind, I want to focus on an issue the article raises in the minds of many runners. How much should we weigh, and how concerned should we be with weight?


Losing weight is one of the primary reasons many people begin to run. If that is the case, then of course weight is a concern. However, I am speaking specifically about people who are of a healthy weight, but are trying to improve their running performances.

I am not necessarily trying to act as an expert here. I do have quite a bit of background, but I am neither a biomechanics expert or a dietician. My main goal with this post is to get people to discuss what they agree and disagree with. What is your take on weight as it pertains to running performance?

I am sure you know someone who would have thoughts about this subject. Share this article with them because I would love to hear their thoughts.

My Take On Weight Loss As It Pertains To Running

There are some that subscribe to the idea that runners shouldn’t be concerned about their weight at all, and that running, along with a healthy lifestyle will make them the prime weight.
That’s is certainly one way to approach it, and there is some excellent support for that idea, but I think there is something to be said for slimming down for a race.

Obviously it is easier to carry something that is light than something that is heavy. Thus the lighter your body is, the easier it is to carry – that is basic physics.

Let’s assume that losing 1 pound would equate to a 0.5% increase in speed with the same amount of energy. I want to stress that there is no specific data to back this claim, this is just a ballpark estimate based on my experience. I would love to hear what others think. If anyone knows any experts, please get their thoughts.

Weight Loss Pace Chart

I am estimating a 0.5% increase in speed, using the same amount of energy, per pound of weight loss. If that is the case then the following chart indicates the increase in pace that would occur with weight loss:

weight loss pace calculator

As I said this is an estimate, but, according to my experience, it seems very plausible. In my opinion, this is a great case for being as trim as possible if you want to run your best, since even a few pounds can make a difference.
However, I think that there is something that is even more important:


The ultimate argument against worrying about your weight is that it may negatively impact your caloric intake. The scary part about this is that, if it happens, you will probably not notice for awhile. In fact, you may notice an increase in performance. However, lack of proper nutrition is a slow bullet.

You see, food is like fuel for your training. You have to make sure you have enough fuel in your car to drive somewhere. Similarly, you need enough fuel in your body to drive your training. Your body’s fuel tank becomes depleted slowly if it is not properly filled after exercise (being depleted.) Think of it as driving 50 miles everyday, but only putting 40 miles worth of gas in your car each day . . . You may start out full, but eventually you are going to run out of gas.

As your body’s fuel tank becomes depleted over weeks, or even months, you will notice weight loss, and at points, you may notice a bump in performance. However, once the fuel tank becomes depleted, your body will shut down. Generally what will start to happen is that you will feel tired and Lathargic, and every run will feel like it is completely draining your body of energy.

In my experience, I have had my best performances when I am as slim as I can possibly be. However, I have also gone to the point of depletion and it resulted in extreme sickness that took months to recover from.

The strategy I use now is to have a target race weight that I try to get down to (in a healthy way) before key races, but I err on the side of keeping the tank full during most of the year.

What at your thoughts? Do you have a prime racing weight, or do you just make sure you are taking in enough fuel? Who is the most knowledgable runner you know? What do they think?

Cover photo courtesy of The New York Road Runners

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 A picture of John Coyle in running stuffJohn Coyle is a recent Graduate of Weber State University where he ran Cross Country and Track. He now runs semi-professionally. He is the Marketing Director for and loves to run and write about running.






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