A Body Tuned for Performance

I’m right now reading Matt Hart’s new book Win at All Costs: Inside Nike Running and Its Culture of Deception, and it’s got me thinking about (among other things) the issue of weight management in running. Last year, you may recall, the running world was rocked by allegations of fat shaming and other weight-related psychological abuse levied against Nike Oregon Project coach Alberto Salazar by Mary Cain and other former NOP athletes. Although Hart’s book focuses on other scandals — particularly the doping allegations that earned Salazar a four-year ban by the U.S. Anti-Doping Agency — the underlying culture of misogyny that fed into the alleged instances of weight-related maltreatment are a major theme.

As the author of the book Racing Weight, and as a coach and sports nutritionist who routinely assists runners and other endurance athletes with what I call performance weight management, I took a keen interest in the running community’s response to this story. Although different individuals had different takes, there was an unmistakable collective backlash against the very notion of actively managing or even talking about managing body weight and body composition as an athlete. Some even went so far as to deny the existence of a connection between weight and performance. “I don’t have a racing weight,” stated elite marathoner Allie Kieffer — herself a past victim of online body shaming — in an interview for Women’s Health.

Not everyone felt this way, though. On November 18, 2019, retired professional runner Jen Rhines offered her perspective in a blog post. She wrote, “For those that choose to be a professional athlete (and are of adult age) I have a strong opinion that body composition is not something that should be ignored. Pretending that it has no impact on performance doesn’t make any logical sense, it’s exercise physiology 101. I absolutely do agree with the athletes that have pointed out recently that weight or body composition should never be singled out as the sole factor to an athlete’s success, or as a source of shame. In addition to this behavior being destructive to the wellbeing of the athlete, it also completely defies logic. Body composition should be accounted for as one part of an athlete’s overall program, along with running, strength training, flexibility, sports therapy, sports psychology, etc.”

In my view, Rhines nails it — the only amendment I would offer is that what she says applies not just to professionals but to any runner who wants to realize their full potential. To pretend that body weight and body composition have no effect on running performance is to ignore overwhelming evidence that, in fact, they do. The latest evidence comes from a study conducted by Jackson Gaddie and colleagues at the University of North Alabama and published in the International Journal of Exercise Science in September 2020. Gaddie’s team used doubled-layered compression garments with gel inserts to add weight to the torsos of 18 male and 18 female runners and then measured the energy cost of running with three different amounts of added weight ranging from 3.5 to 7 lbs, as well as without extra weight. 

Among women, 3.5 percent more energy was required to run at the same pace regardless of how much extra weight was carried, while for men, energy cost increased with each increment of weight added. The authors concluded that “modest increases in body mass can produce detectable and potentially important levels of running economy impairment.”

Obviously, gel inserts are not the same thing as body fat, nor is the instantaneous addition or subtraction of weight in the form of gel inserts the same thing as gaining or losing body fat over time. That’s why scientists have also studied the relationship between body weight/ composition and running performance through real-world observational studies. In one such study, Swiss and Greek researchers measured body fat levels in 134 marathon runners and compared these measurements against their marathon times. In agreement with previous studies of similar design, they found a strong correlation between body fat levels in the trunk and upper limbs and race times, with the fastest runners carrying the least fat in these areas.

All in all, the relevant science strongly suggests that every runner does have a racing weight — an optimal performance weight defined by a lean body composition. The problem is that, in today’s reality, the pursuit of racing weight can be risky, with many runners developing an unhealthy obsession with their weight or appearance and using unhealthy methods to achieve their goal. The all-too-common consequences include stress, anxiety, disordered eating, body dysmorphia, and health problems ranging from nutrient deficiencies to amenorrhea. This is why many in the running community today advocate placing a taboo on any discussion of the topic of performance weight management.

The way I see it, though, the folks on this side of the debate really aren’t so far apart from the likes of Jen Rhines and me. What I mean is that there does exist a healthy, low-risk way to pursue one’s optimal racing weight, and it looks a heck of a lot like the approach taken by Allie Kieffer and others who say they don’t believe in racing weight yet whose performance demonstrates that they have achieved their optimal racing weight nevertheless.

Following are my top three items of advice on the subject of performance weight management for runners. You can read them either as an argument against consciously pursuing your racing weight or as guidelines for achieving your racing weight. Choose whichever interpretation you’re most comfortable with.

1. Don’t set goals.

The first mistake that many runners make in the effort to achieve their optimal racing weight is to set a goal to attain a specific weight or body fat percentage — usually a round number. The problem with such goals is that they are utterly arbitrary; there is no way for any runner to accurately predict the weight or body fat percentage at which they will perform best. Chasing a number that’s not right for you is likely to negatively impact not only your running performance but also your health.

Even top professional runners, including two-time U.S. 5000m champion Lauren Fleshman, have been known to make this unfortunate and sometimes costly mistake. In a recent New York Times article, Fleshman revealed that she once believed she needed to lose eight pounds to reach her optimal weight, but it turned out she was wrong, and instead of yielding the performance breakthroughs she expected, her weight-loss efforts resulted in amenorrhea, stress fractures, and erratic training.

It’s important to understand that racing weight is functionally defined. By definition, your optimal weight for running is the weight at which you perform best and most consistently. Hence, the only way to determine this number with certainty is to actually achieve peak fitness and performance. The principle of “form follows function” applies perfectly to the relationship between body weight/composition and performance. You don’t arrive at peak performance by attaining a certain weight or body fat percentage; rather, you optimize your body weight and composition in the process of attaining peak performance. Which leads me to my second item of advice on the subject of performance weight management.

2. Focus on the process.

The primary means by which a runner’s optimal racing weight is arrived at are diet and training. Because it’s impossible to predict your optimal racing weight, and because the phenomenon is functionally defined, the best way to work toward it is to focus on the process of eating right and training smart, trusting that by doing so you will eventually get where you need to go. Too often, runners do the opposite, viewing any weight loss as good weight loss regardless of how it is achieved. 

Remember, by definition your optimal racing weight is the weight/body composition at which you perform best and most consistently. The most effective — and arguably the only — way to eat and train your way to racing weight, therefore, is to eat and train for performance. You can lose a lot of weight very quickly by not eating anything, for example, but your performance would suffer.

The most successful runners — those who consistently perform at a high level — tend to eat and train in similar ways. With very few exceptions, they do not follow popular diets. They do not eliminate entire food groups or avoid certain macronutrients. They don’t fast or restrict calories, nor do they do anything else that’s extreme, unbalanced, or difficult to sustain. Instead, they maintain a balanced and inclusive diet based on a wide variety of natural, unprocessed foods. They eat things they enjoy and eat enough of them to satisfy their appetite. Show me a runner who’s running as well at 45 as they did at 25 and I’ll show you a runner who does these things.

On the training side, the most successful runners again put process first and let form follow function. They do not run an extra mile to “justify” eating a cookie or to make up for having eaten a cookie. Instead they obey proven best practices in training for maximal performance, including the 80/20 rule of intensity balance, and trust that their weight and body fat levels will take care of themselves as they journey toward peak fitness.

3. Prioritize healthy relationships with food, exercise, and your body.

Over the past 20 years or so I have talked to scores of athletes about their eating habits, and the most important pattern I’ve observed has nothing to do with what they do and don’t eat. Rather, it’s that the most successful runners have healthy relationships with food, exercise, and their body. Put another way, I’ve never known a runner who loved their diet but was unhappy with its long-term results, or known a runner who did not love their diet but was happy with its long-term results. In our society, we are not accustomed to thinking this way, but it’s absolutely true that if we focus on nurturing a love for our diet, our training, and our body, the results will follow.

This isn’t just a bunch of touchy-feely pop psychology I’m throwing at you. Science backs up my observation. For example, a study published earlier this year in Nutrition and Dietetics reported that, among more than 1,600 men and women who were either following or had recently abandoned a particular diet, individual scores on a standardized measure of dietary enjoyment strongly predicted the duration of adherence to the diet. 

In my one-on-one work with runners who are concerned about their weight I put a major emphasis on nurturing healthy relationships with food, exercise, and the body, and it pays. Jason is a talented young trail runner with elite aspirations. He’s stockier than most elite runners, though, and acutely aware of the fact. When Jason asked me to help him manage his weight for performance, I analyzed his current habits and recommended a few small adjustments such as snacking less on calorie-dense foods like nut butters and more on high-satiety foods such as veggie sticks. 

A few minor incidents, however, including an over-the-top day of carb loading before a race, alerted me that Jason was beginning to engage in unhealthy restrictions. So we talked it out. I urged him to stop weighing himself and comparing his body to those of other runners and to put a little more enjoyment back into his diet. He reacted to this advice with gushing relief and, more important, he put it into practice. Today, Jason continues to close the gap on the elites and is having fun doing so, and isn’t that really the whole point?