How Gen Z is leading latest boom in distance running

• Distance running is experiencing a surge in popularity, particularly among Gen Z.
• Athletes who under-fuel their bodies risk a condition called Relative Energy Deficiency in Sport (REDs).
• Symptoms of REDs can include fatigue, hormonal problems, bone density loss, and decreased performance.

Distance running is having a moment — and it’s largely being led by Gen Zers, whose participation has been on the rise since the pandemic ended. 

In recent years, we’ve seen high-profile celebrities such as Harry Styles, Colin Farrell, Kevin Hart, Ashton Kutcher, Jennifer Connelly and Chelsea Clinton, among others, complete full marathons. In turn, races of all distances nationwide are seeing a dramatic spike in participation. 

And that certainly goes for all of the events — 5K, 10K, half-marathon, marathon relay and full marathon — that will take place Dec. 13-14 in downtown West Palm Beach at the annual Palm Beaches Marathon weekend.

But back to Gen Zers: According to Road Runners Club of America “from 2021 to 2024, the percentage of finishers aged 20 to 29 have increased from 16.4% to 24.5% in the marathon, 17.1% to 26.2% in the half marathon, 13.9% to 20.6% in the 10K and 12.3% to 17.2% in the 5K.” 

In addition, there’s been a marked increase in membership in running clubs across the nation. 

As Runner’s World noted earlier this year, “Run clubs are replacing dating apps. Brands are tapping these groups for sampling and sponsorships. Celebs like Diplo and blink-182 drummer Travis Barker are starting their own run clubs. Around 7 percent of runners surveyed for Running USA’s annual report in 2023 stated that they were part of a running club. And Strava saw a 59 percent increase in new clubs in 2024, according to the tracking platform’s annual Year in Sport report, with Gen Z as the leading contributor to that growth.”

TikTok and Instagram are chock-full of fitness and beauty influencers documenting their training and race-day experiences — and their followers are taking note. This has led to more sneaker and apparel brands targeting their distance running gear to younger consumers, further fueling the rise in the sport’s participation rates.

Seeing so many young adults lean into becoming endurance athletes is certainly heartening — especially when you think about how beneficial this could be for decreasing the nation’s obesity rates. 

That said, there are some aspects of becoming an endurance athlete that young folks — especially women — must stay vigilant about avoiding so as to ensure they can partake in their favorite road races for years and decades to come.

Dangers of Relative Energy Deficiency in Sport (REDs) 

We all know that proper nutrition — which includes sufficient caloric intake— is the foundation for undertaking any kind of athletic pursuit. 

And this is especially true for endurance sports — running, cycling, swimming and the like. 

But regardless of one’s age, gender or ability level, there’s a perpetual risk for endurance athletes to under-fuel their body’s basic caloric needs. 

When that happens, the athlete becomes vulnerable to suffering from a syndrome known as “Relative Energy Deficiency in Sport” (REDs). 

The term was introduced by the International Olympic Committee in 2014 and while it was originally coined to expand on an existing condition for elite competitors called “the female athlete triad” (which is comprised of irregular menstruation, loss of bone mass and disordered eating), in recent years experts have been stressing that REDs can affect anyone. 

CNN explains that “Relative Energy Deficiency in Sport (REDs) occurs when an athlete of any gender has overtrained and/or under-eaten for a prolonged period in an attempt to improve their performance, often without knowing the dangers of failing to compensate for the energy they expend in training and racing.” 

The potential complications of suffering from REDs are myriad and they include the following: 

• Fatigue 
• Weight loss 
• Missed or irregular periods
• Hormonal problems 
• Digestive problems 
• Bone density loss 
• Stress fractures 
• Repeated muscle or connective tissue injuries 
• Cold intolerance 
• Low sex drive 
• Frequent illness 
• Slow heart rate 
• Low blood pressure 
• Decreased athletic performance 
• Hair loss 
• Trouble focusing 
• Irritability 
• Depression 
• Anxiety 

Identifying — and treating — root causes of REDs 

Many athletes suffering from REDs may have other mental-health complications that contribute to the condition. 

Body image issues and/or disordered eating habits are the most commonplace. It also happens frequently to folks who put intense pressure on themselves and/or are perfectionists. 

In those instances, the athlete may benefit from being treated via a multidisciplinary approach that includes education and consultations with experts such as nutritionists, sports psychologists, sport-specific coaches, and/or sports medicine doctors. 

Another potential factor perhaps contributing to recreational endurance athletes suffering from REDs is how many people nowadays are taking GLP-1 medications to control their weight. 

Those on GLP-1 medications usually have decreased appetites as well as decreased overall interest in, and enjoyment of, food. 

It’s easy to see how those on GLP-1 medications who become involved in an endurance sport may inadvertently end up suffering from REDs during their training. 

For most recreational athletes who may be suffering from REDs, the condition can usually be rectified by a combination of eating a well-planned, nutrient-dense diet and incorporating more rest days into the training program. That’s where consultation with the nutritionists, coaches, and healthcare experts can be so beneficial. 

The bottom line is that participation in an endurance sport should be a fun and rewarding pastime — one that contributes to, rather than detracts from, your overall health and well-being.  

Palm Beaches Marathon weekend

If you go

What: U.S. Polo Assn. Palm Beaches Marathon weekend; races include 5K, 10K, half-marathon, marathon relay and full marathon 

When: 6 a.m. Dec. 13-14

Where: Start and finish lines at 104 Datura St. in West Palm Beach 

Info: palmbeachmarathon.com.   

Steve Dorfman is a journalist for The Palm Beach Post, part of the USA Today Network of Florida. He writes about all aspects of health, fitness and wellness. If you have news tips, please send them to sdorfman@pbpost.com. Help support our local journalism, subscribe today.