The Formula

A common way of assessing optimum running weight is by “doubling the inches” of your height to get a ballpark figure on your best weight. However, the issue with this formula is it does not take into account one’s bone structure, natural muscle mass, and goals in the sport.

With that stated, it is important to first complete a rudimentary test of your bone structure before calculating your optimum racing weight. Hold out your right hand in front on you. Using the index finger and thumb of your left hand, wrap these fingers around your right wrist.

If the fingers touch but don’t overlap, you have a medium bone structure and/or musculature. If your fingers overlap, you have a small frame. If your fingers do not touch, you have a larger than average bone structure.

Now, with you frame assessed in a general sense, let’s do some quick calculations using our “double the inches” formula as a baseline.

  • Small Frame– Double the inches, then subtract 5-10lbs to establish an optimum running weight for health and performance.
  • Medium Frame– The formula works! Keep it the same.
  • Large Frame– Double the inches, then add 5-10lbs.

Pretend we have a hypothetical runner who is 5’10 (that is 70 inches in height). It does not matter if this runner is male or female, but females often weigh slightly less than males at the same height.

If we “double the inches” for this runner as noted above, we come to 140lbs in weight. So, based on frame size, the following values would hold true.

  • Small Frame– 5’10, 140lbs – (5-10lbs) = 130-135lbs
  • Medium Frame– 5’10, 140lbs
  • Large Frame– 5’10, 140lbs + (5-10lbs) = 145-150lbs

Note- This formula represents numbers that may be hard to attain for many people even after a period of weight loss.

The figures above are geared towards athletic individuals who run regularly, compete recreationally or to a serious degree, and are looking to OPTIMIZE running performance.

Manipulating the Numbers for Optimum Health

Once you have established an optimum running that works for you, we can look at how to manage that figure over the course of the year. This section will provide a realistic look at how to use training and diet to optimize running weight when it matters most

“Sarah” will be our hypothetical model for this example. She is a medium framed competitive runner who races most frequently in the fall and spring. In the winter and summer, she runs recreationally to stay fit. Sarah is training for a fall marathon this year. She is 5’6 inches tall, and her optimum running/racing weight is around 125lbs based on previous experience.

In the summer, while training recreationally, Sarah likes to keep her weight around 130lbs as she can eat what she likes at this weight without counting calories or having to stress over training.

When preparing for her fall marathon, her weight will gradually drop through training to her optimum 125lbs a week or two before the race (or even slightly less). This weight is hard to maintain for Sarah, but she knows she races best lean and light.

Following her goal marathon, Sarah will want to quickly regain weight back up to her “normal” 130lbs. This will help her muscles recover from a season of training, protect her immune system, and allow her to train hard again in the spring. Even elite marathoners like Meb Keflezighi plan to gain weight after a marathon once they have achieved their racing weight for a few weeks prior to a big event.

Hopefully the formula above and ideas about planning one’s weight throughout the year will help you to answer one of running’s most common questions.

If you want to learn more about how to obtain and maintain your ideal body weight, read Running Shoes Guru’s “Run Lean, Run Strong” guide.