The Female Athlete Triad: A Syndrome Affecting Women Runners

For many runners, burning extra calories is a welcome benefit of training for a race like a marathon. But it can turn into a health risk when athletes struggle to maintain a healthy weight and become undernourished. Lean bodies are typically what we associate with being in shape, but it shouldn’t come at the expense of your health.

In female athletes, not having enough calories can have some serious hormonal implications. This problem is so common that doctors have a name to describe it: The female athlete triad.

The downsides to calorie deficiencies  

The female athlete triad occurs when there’s a combination of inadequate calorie intake, menstrual abnormalities and bone degradation. 

Inadequate calorie intake, or inadequate eating, describes anyone who doesn’t regularly eat enough to replace the calories burned while running or exercising. Sometimes, these calorie deficiencies can result from conditions like anorexia (severe calorie restriction) or bulimia (binging followed by purging behavior). Unfortunately, eating disorders are seen more among athletic women than compared to women who aren’t training consistently.

Menstrual irregularities can impact those who have these calorie deficiencies. Some women experience oligomenorrhea (fewer periods), while others develop amenorrhea (no periods) when they aren’t getting enough calories to replace what they lose while exercising.

Why does this happen? Well, there’s a complex interaction of hormones that are required to signal your period to start, and those signals are disrupted when someone doesn’t eat enough calories. In addition, this might also lead to reduced estrogen levels — sometimes levels as low as those seen in postmenopausal women.

More recently, there has been growing concern that low estrogen levels in these women may be increasing their risk for heart disease and stroke due to cardiovascular disease. Estrogen increases good (HDL) cholesterol and decreases bad (LDL) cholesterol, which might explain the increased cardiovascular risk in those with low estrogen levels. Estrogen also affects your blood’s ability to flow through vessels, also influencing these risks.  

Ultimately, the full extent of the cardiovascular risks for those affected by the female athlete triad isn’t completely understood, but it’s a growing area of research. 

Skeletal demineralization (bone break-­­down) is the third and final component of the female athlete triad. Normally, our bones are constantly being remodeled and reformed. In this process, the overall bone mass remains constant as old bone is broken down and replaced with new.

A number of factors can disturb this delicate balance, however, including low estrogen. When this happens, more bone is broken down than is being formed. The bones weaken, making them susceptible to stress fractures — small cracks in the bone typically caused by overuse — and more serious fractures even after minor trauma.

Many different factors can disturb this balance, including the amount of estrogen in your body. Because many women with the female athlete triad have low estrogen, their bone break-down process happens faster than their bone formation.

How to avoid the female athlete triad when exercising

We’re still learning the health risks associated with the female athlete triad. The best thing you can do to protect yourself is to recognize the warning signs of the female athlete triad and see your doctor if you’re concerned. Some of these warning signs include:

• Unhealthy eating habits such as excessive dieting and binding and purging
• Fewer, irregular or absent periods
• Bone pain, stress fractures or fractures from minor injuries

Listen to your body to prevent other injuries

In addition to preventing the female athlete triad, there are other reasons to stay in tune with your body as you’re exercising.  

Don’t forget to stretch and do a proper warm up. Just like a slow progression in running distance, your body needs adequate time to warm ­up before heavy training or competition. A light short distance jog and gentle stretching will assist the body and muscles in preparing properly for more intense exercise.  

The warm up routine that works best for you will likely vary from one another, but ultimately, you should feel comfortable with your routine — including stretching, warm-­­up, meals, shoes and clothing — before marathon day.

Unfortunately, not all injuries can be avoided. From blisters to leg cramps, it’s essential to be prepared to modify your running if an unexpected problem arises. As a runner, you shouldn’t “push through” significantly painful symptoms.  

If you develop unexpected limitations, slow your pace, walk, rest or stretch before continuing. If you develop major symptoms such as chest pain, difficulty breathing, lightheadedness or confusion, stop immediately and ask for help.

Remember, your body is more important than a new PR. You’ll have the most success when you train appropriately, plan well, listen to your body and, most of all, prioritize your safety. 

Dr. Mark Harrast is a sports medicine physician and medical director of the Sports Medicine Center at Husky Stadium and the UW Medicine Seattle Marathon. He specializes in diagnosing and treating sports-related injuries and illnesses in endurance athletes, runners and triathletes. He is also an accomplished competitive endurance athlete himself.