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If you’ve ever watched an open run race or a triathlon run leg, it’s fairly obvious that the top contenders look remarkably similar in one important way: They are all devoid of those pesky extra 10 pounds (or more) that plague many athletes today.
One of the most important things to keep in mind for sports performance at all levels is that the aerobic engine (which is genetic) should match the body frame. So if you have a Prius engine in a flatbed truck frame, you might see more gains by whittling down the frame than you ever do from just taxing the engine alone.
Though differences in weight certainly exist due to height, frame and genetics, the importance of being lean while still healthy cannot be overstated. The triathlon run leg is where the impact of extra weight is most obvious in terms of split times. For a before-and-after example, check out Heather Jackson, a pro triathlete who has always turned in top bike splits. After losing 25 pounds following her first year racing, she became a contender for top run splits as well.
If you’re carrying a lot of extra body fat or naturally have a large frame, it’s easy to get discouraged instead of inspired by examples of pros with single-digit body fat percentages. But shaving off pounds can make as much or more of a difference to age-groupers. Joseph McLeod, a competitive age-grouper in Atlanta, started with a quest in January 2008 to run a 10K in four months—he could barely run a mile, and weighed 245 pounds at 5-foot-11. After completing that first race in about 50 minutes, he continued training and losing fat over the next three years; his current PR is a sub-37-minute 10K run at a race weight of 175 pounds. What was once a goal to simply complete a marathon is now a goal to qualify for Kona.
How Fast Could I Go?
Though there are many variables and no way to actually prove it, conventional wisdom is that times will improve about two seconds per mile per pound of fat loss. That may not sound like a lot, but when you do the math, it can add up to big numbers over longer distances!
Imagine losing 10 pounds of fat and being rewarded with a one-minute 5K PR, a two-minute 10K PR, a four-plus-minute half-marathon PR, and a near 10-minute marathon PR—all with your current training and fitness level!
What is my optimal race weight?
One of the biggest challenges with finding and achieving ideal race weight is figuring out what is realistic for you personally, then going about it in a healthy way that’s sustainable, accounts for proper fueling and takes the long view in terms of overall body health. Here are a few resources for getting started:
- Matt Fitzgerald, author of Racing Weight, offers up his race weight estimator
- Owen Barder, the author of Running for Fitness, attempts to quantify the effects
of weight loss, all other factors being equal: Runningforfitness.org/calc/diet/weighteffect
- Dr. Paul Vanderburgh developed this calculator based on his study, which attempts to quantify the effects of age and body weight on your run splits: