The Dark Side of Fitness

Inside the often unfortunate, sometimes weird, and occasionally gruesome drawbacks of fitness fanaticism.

April 2016

—Photography by Tom Speruto

Because the temptation to use performance-enhancing drugs is surprisingly strong. 

Endurance sports require near superhuman physical feats. As such, athletes have been experimenting with all kinds of substances in an effort to improve performance since…well…forever. To wit: Early 20th-century Tour de France cyclists took strychnine (used as a pesticide today) and held ether-soaked handkerchiefs to their mouths to stay alert and dull the pain. Today, the Tour de France, the Olympic Games, and other high-profile sporting events employ drug testing in an attempt to root out would-be cheaters. But blood and urine checks on amateur and sponsored endurance athletes competing in even relatively well-known events are much less frequent. With the help of Dr. John Hill, who served as the medical director for the Leadville Race Series for seven years, we looked at a handful of medications* for which endurance athletes are finding intriguing off-label uses. —Matt Hart

Methylphenidate (Ritalin)

Prescribed use: A stimulant used to treat ADHD, narcolepsy, sleep apnea, and shift-work-associated sleep disorders.

Athletes like it because: It increases performance by heightening energy, focus, and aggression—all good things for long-duration events. 

But there are downsides: It can cause fever, sore throat, headache, and vomiting. Long-term use of stimulants can lead to suboptimal sleep (and all its corresponding maladies).

Levothyroxine (Synthroid)

Prescribed use: Treating hypothyroidism, a common hormonal imbalance that causes fatigue, weakness, and weight gain (among other symptoms) and disproportionately affects women middle age or older. 

Athletes like it because: It improves energy levels and battles the fatigue caused by high-intensity, high-volume training. The drug also increases metabolism, ostensibly making weight loss easier—a serious draw for endurance athletes.

But there are downsides: The meds can lead to osteoporotic fractures, heart arrhythmias, jitters, insomnia, and increased heart rate, among other side effects.

Sildenafil (Viagra)

Prescribed use: Treating erectile dysfunction. 

Athletes like it because: The drug inhibits an enzyme that controls blood flow in specific parts of the body, including (but not, ahem, limited to) the pulmonary system (i.e., your lungs). Athletes competing at high elevations use the drug to mitigate the effects of high-altitude pulmonary edema, or fluid in the lungs.

But there are downsides: The main anti-performance side effect is a drop in blood pressure. Other negatives include stroke and heart attack, as well as headaches; flushing in the face, neck, or chest; and upset stomach. There are conflicting studies on the drug’s effectiveness for athletes: A Stanford University study found a 39 percent increase in time-trial performance at a high elevation, but subsequent University of Miami  research found “no clear benefits.” 

Prednisone (Deltasone)

Prescribed use: Treating inflammatory and autoimmune diseases such as allergy disorders, skin conditions, ulcerative colitis, arthritis, lupus, psoriasis, and breathing disorders. It’s also sometimes used to treat side effects plaguing cancer patients. 

Athletes like it because: It provides an incredible energy boost for day-to-day training or multiday events. It also suppresses the body’s natural inflammatory processes, diminishing stiffness and pain and therefore allowing athletes to return to training more quickly. 

But there are downsides: Prednisone can bring on headaches, dizziness, weight gain, and difficulty sleeping, as well as extreme mood swings or personality changes. Long-term use of the drug can lead to serious health issues, including osteoporosis, vision problems, and life-threatening infections.


Prescribed use: This hormone is used to treat males with hypogonadism. It’s also commonly prescribed as treatment for age-related decline of testosterone production.

Athletes like it because: The main anabolic steroid hormone produced by your body, testosterone is the primary driver of virility: It increases muscle mass, strength, energy, motivation, and greatly improves recovery from exercise. 

But there are downsides: Side effects can include enlargement of the clitoris in women and breast swelling and shrinking of the testicles in men, as well as acne.

Acetazolamide (Diamox)

Prescribed use: This carbonic anhydrase inhibitor is used to treat glaucoma, epilepsy, and acute mountain sickness.

Athletes like it because: It affects CO2 balance in the body, which increases respiration and therefore lessens the effects of racing at high elevations. It’s popular among athletes who live low but want to race high because it can prevent the headaches, nausea, and dizziness caused by acute mountain sickness. 

But there are downsides: Diamox can induce a distracting tingling sensation in the fingers and toes; very rarely, it can cause electrolyte imbalances.

*All of these drugs, except for sildenafil and levothyroxine, are banned by the World Anti-Doping Agency. 

Because you might tick off your immune system. 

While moderate exercise has been shown to bolster the immune system, overdoing it on the athletic front can actually decrease the body’s ability to fight everyday bugs. “The line between peak performance and overtraining-fueled sickness is almost invisible,” says Stephanie Morish, a certified holistic nutrition consultant who works with clients of Denver Sports Recovery, a drop-in center that gives both professional and everyday athletes access to state-of-the-art recovery tools. “High-performance athletes often have suppressed immune systems, making them susceptible to colds and infections.” How does too much physical exertion reduce the immune system’s prowess? People who are training for big races tend to skimp on three things: calories, sleep, and time spent off their feet. These ingredients combine to do the body a real disservice. “The body just breaks down,” Dr. John Hill says. “That’s how many high-level athletes know they’ve overtrained—they get a cold.” 

Because being a competitive athlete can bring out your demons.

It’s difficult for Wendy Greene to pinpoint exactly why or when she became too focused on her body and fitness. Maybe it was at 12 years old when she first began lifting weights with her dad when they were living in northern Wyoming. Or maybe it was when she was assaulted at 19 years old. Or maybe, she says, she has been compulsive and anxious since she was born. “Genetics loads the gun sometimes,” she says. “Life pulls the trigger.”

Whatever it was, Greene, 33, says she’s always had a tendency to be at the extreme end of everything. For example, Greene didn’t just continue lifting weights to stay in shape; she began competing in bodybuilding events. And she didn’t just go to CrossFit; she became a CrossFit instructor. Her other jobs—as a wildland firefighter and now a surgical trauma nurse at Denver Health—have also fed her need for constant, high-pressure stimulus. “I’ve always had an inability to focus,” Greene says. “I like things that make me pay attention because if I stop, I have to face myself.”

Facing herself became unavoidable in 2011. Greene’s anxiety and other emerging compulsions—like obsessively counting calories, chewing food and then spitting it out, and working out to the detriment of her social life—had her drowning in what felt like a pool of depression. She went to see a therapist, who helped Greene understand she might be experiencing orthorexia (an obsession with eating only healthy foods) and compulsive exercise disorder (prioritizing exercise over everything else), both mental health issues that research suggests are more common among competitive athletes. “I wasn’t underweight,” Greene explains, “so no one knew I was struggling.” But she was. “Social media didn’t help. CrossFit stuff is all over Facebook, and I felt the pressure to maintain the appearance—the abs, the bicep veins, the superhero look.”

Greene checked herself into Denver’s Eating Recovery Center for a 40-day partial hospitalization in 2011. The program changed her life by giving her coping skills. “In addiction, everything is black or white,” she says. “I had a hard time dealing with gray.” She learned though. She took herself off Instagram. She began looking at food not as strictly good or bad. She resolved to call a friend if she was isolating herself. Today, she still does CrossFit but limits it to a few times a week. “I’m still obsessive, and working out is still a part of my life,” she says, “but I’ve discovered that there’s more to life than CrossFit.”