Why Thin Does Not Equal Fast

Attention runners – it’s time to talk about one of the biggest myths out there in the running community: thin = fast. 

Where does this idea of thin = fast come from?

For some athletes, this concept may have first been introduced by a well-meaning coach or a parent. For others, the media may be a culprit as pictures of extremely thin runners are easy to come by.

Required weigh-ins by performance staff at any level can also reinforce the idea that performance in a sport is weight dependent. Unfortunately, this concept and these practices can lead athletes, especially runners, down a slippery slope. Athletes may become consumed by weight loss, weight control, food rules, underfueling, and maybe even an eating disorder. 

It may seem like it makes sense at first. The thinner you are, the less weight you have to carry and thus the faster you can run. Right? However, this isn’t so much the case. In fact, an “optimal running weight” may not exist at all.

To dig a little deeper into this topic, let’s talk about what it takes achieve this thin runner ideal. 

What does it take to be thin? 

It’s important to first talk about what being “thin” entails. Some individuals, due to genetics, have naturally thin builds. They can eat enough, enjoy what they want, train appropriately and live healthfully in a smaller body. However, when this isn’t naturally the case, being thin entails much more. 

Reaching a lower body weight than your natural body weight entails a caloric deficit temporarily or long-term. To create a caloric deficit, one must cut calories or increase their training and exercise. A lower running weight may initially be associated with faster running times, a new PR, and feeling lighter on your feet. However, this is what we call the “honeymoon phase” as it doesn’t last for long.

When a lower weight is achieved as a result of a calorie deficit, runners will eventually start experiencing negative effects. Health and athletic performance may be hindered by “low energy availability” or “relative energy deficiency in sport” (RED-S).

Low Energy Availability

From a performance perspective, low energy availability can lead to:

-Increased fatigue

-Decreased stamina

-Decreased intensity

-Longer race times

-Limited training gains

-Poor concentration/focus during running events

One’s general health will also start to be greatly impacted by low energy availability. In the short-term, Individuals struggling with low energy availability have a higher risk for:

-Irregular/missing periods

-Injury

-Illnesses

-Bloating/gas

-Mental health concerns

In the long-term, a consistent calorie deficit can also put you at a higher risk for:

-Heart issues

-Weakened immune system

-Decreased bone density

-Other health consequences

It’s important to note that even though low body weight, bodyweight fluctuations, and weight loss can all be signs of RED-S, these specific weight “red flags” don’t always occur. Long story short, experiencing the impacts of low energy availability can completely negate any advantage that a lower weight may provide. 

Shedding light on the thin = fast myth in media

For a lot of individuals and runners, focusing on a specific weight can get in the way of physical AND mental health.

In a recent Runner’s World article, Paige Roberts, a former collegiate runner, talks about how body comments by her coach and a false impression of her “ideal running weight” led to years of battling an eating disorder. Paige states that she continues to get support regularly to ensure she maintains a healthy mindset around food and exercise. 

In 2017, Allison Baca opened up about her experience striving for unrealistic weight goals on her blog, Thinner, Leaner, Faster, Weaker, and later in an article for Women’s Running. She talked about her obsession with daily weighing and food/training tracking. Allison had cut out carbs, started training excessively, and found herself deep in a binge/restrict cycle between meets.

For Allison, this dangerous pattern led to isolation from friends and teammates in addition to osteopenia (the early stages of osteoporosis) at only 19 years old. She experienced persistent injuries that kept her out of training/meets, and mental exhaustion from trying to keep up with food rules. The negative impacts of her efforts finally set in, leading her to quit her division 1 team before her senior year.

In 2019, athlete Mary Cain spoke about her experience at Nike’s Oregon Project in a ground-breaking New York Times article. She specifically highlights the negative consequences female athletes can face when they are fed the thin equals fast narrative.

Oftentimes female athletes, especially runners, are expected to meet athletic standards similar to male athletes. These standards are based on how boys develop, not girls. This can hinder female’s physical and mental health, in addition to their performance and running career. Mary, the youngest American track and field athlete to make a World Championships team, underwent this exact experience.

What can actually make you a faster runner?

Being a fast runner requires proper fueling, optimal training, and adequate recovery.

Fueling

Proper fueling requires a mix of different food groups and high quality food choices. Most importantly, is involves eating enough calories on a daily basis to meet both the needs of your body AND the needs of your training. The International Olympic Committee’s Athletes Plates can be a great resource when beginning to navigate what proper fueling looks like. 

Training

Optimizing training includes adequate training but also proper rest, stretching and consistent training over time. Training participation can be easily interrupted by issues resulting from low energy availability, like repeated injuries or illnesses. In fact, female runners with irregular periods are more at risk for injury and are six times more likely to sustain a stress injury. Males facing low energy availability also have a higher risk of injury too. 

Recovery

Wrapping up each training session with proper recovery can go a long ways. Proper recovery includes adequate hydration and a mix of at least carbohydrates and protein after a training session.

Taking advantage of recovery with proper nutrition can help replenish energy stores, reduce the risk of low energy availability, increase energy levels, and build and repair muscles for future workouts. Timing is essential too. Aiming for a carbohydrate and protein based snack within 30 minutes of finishing up training or a full meal within 45-60 minutes can help you get the most out of your training for future speed and endurance. 

Looking for sports nutrition guidance to help your optimize speed and get the most out of your training? Our Certified Sports Dietitians have experience providing guidance for athlete of all levels and sports. You can check out our sports nutrition packages here.