Calculating Your Optimal Racing Weight

The lighter you are, the faster you run. It makes sense because the lighter you are, the less weight you have to carry around, making it easier for you to increase your speed.
While there are other factors at play when it comes to making one runner faster than others, body weight certainly plays a greater role than most. When running, your body has to overcome the force of gravity to lift you off the ground and move you forward. The lighter you are, the less energy your body uses to move against gravity, minimizing your energy cost at any given pace.
This is where a runner’s optimal racing weight comes in. All runners have their own ideal racing weight, which is basically the lowest weight they can healthily attain to support their peak running performance and recovery. This varies from one individual runner to another and is influenced by factors such as gender, body frame type, and height among others. A tall runner with a broader body frame, for instance, cannot expect to get as light as a shorter runner with a much smaller frame.
At the same time, being light does not mean you’ll automatically be the fastest runner in the field. You also have to be extremely fit, adopt a training schedule to boost your speed, and also have good racing tactics.

How Does Weight Effect Your Speed?

Running Efficiency

As mentioned earlier, the lighter you are, the less energy your body spends overcoming gravity. A study published in the Journal of Experimental Biology showed that altering a runner’s weight had a direct effect on the metabolic cost of running. The findings indicated that the metabolic rate decreased with a corresponding decrease in weight, hence increasing the runner’s efficiency and speed.

Oxygen Delivery

Your body demands more oxygen as you run. Since larger people are less efficient at delivering oxygen throughout their bodies, they are more likely to run out of breath, become tired, and post poorer performances than their lighter counterparts.

Heat Dissipation

Your body generates a lot of heat when running and this needs to be quickly dissipated to avoid overheating. The more fat tissue you have, the more difficult it is to lose heat as the fat traps it within the body. This not only negatively affects your performance but also increases the risk of heat exhaustion.

Body Fat And Your Ideal Racing Weight

Speaking of fat tissue, the lower your body fat percentage, the closer you are to attaining your optimal racing weight. You see, your body weight is a combination of muscle, bone, water, and fat mass. Out of all these, you have the greatest control over your body fat. There isn’t much you can do to change your muscle, bone or water mass and messing with these can actually be detrimental to your health.
While all top runners have low body fat levels at their optimal racing weights, they are not equally lean. This is because body fat levels are determined by genes, gender, age, and other individual factors beyond our control. However, with the right diet and training, it is possible to overcome these factors to attain your ideal racing weight.
As you pursue your optimal racing weight, keep in mind that it is possible to become too lean. It can be easy to get so caught up in the chase for lower numbers that you compromise your health. Dangerously low body fat levels can lead to impaired performance, a weakened immune system, brittle bones, and a host of other health problems. To avoid this, it is better to find your ideal lowest body fat percentage depending on your age, gender etc. and work within those parameters.

How To Find Your Optimal Racing Weight

While you can’t predict your optimal racing weight beforehand, there are ways to get an estimation. Matt Fitzgerald, certified sports nutritionist, sports coach, and author of ‘Racing Weight: How to Get Lean for Peak Performance’, provides this formula to estimate your ideal racing weight:
  1. First, determine your goal body fat percentage i.e. what you’d like your body fat percentage to be.
  2. Next, calculate your goal lean body mass percentage i.e. 1.0 – goal body fat percentage (from step 1) expressed in decimal form.
  3. Then get a scale that also provides body fat percentage, weigh yourself, and note both figures down.
  4. Calculate your lean body mass by taking your current body fat percentage (from the scale’s reading) and subtracting it from 100%, then multiplying the result by your current weight from step 3.
  5. Finally, calculate your ideal racing weight by dividing your current lean body mass (from step 4) by your goal lean body mass percentage (from step 2).
Alternatively, you can use Fitzgerald’s handy online calculator to estimate your optimal racing weight based on your current fitness level, age and gender. Note that this number isn’t gospel truth and should only be used as a guideline to work towards.
The surest way to get your perfect racing weight is to train hard, get into the best shape of your life or run your best race then weigh yourself and get your body composition measured afterwards. This should give you a fairly accurate idea of what your ideal racing weight is.

Achieving Your Optimal Racing Weight

Reaching your optimal racing weight calls for a more focused approach than spending more time on a trainer or increasing your workout sessions. For excellent results, develop better eating patterns. For instance, eating a large nutritionally-dense breakfast is the best way to manage your appetite and maintain constant energy throughout your day. Additionally, learn to choose quality over quantity when it comes to calories by selecting foods that give you more satiety per calorie. This includes foods rich in proteins, fiber, calcium, and fatty acids i.e. fruits, vegetables, dairy products, and nuts.
Also, remember to listen to and understand your body. If you feel sluggish, unwell or excessively weak when running, you’ve probably fallen below your ideal weight and your health could be in danger. Achieving your optimal racing weight, therefore, calls for a delicate balance between low body fat percentage, a healthy body, and peak running performance.