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What is Causing My Leg Pain?

By Mederic M. Hall | Nov. 13, 2018, 6:32 p.m. (ET)

Leg injuries

It started as a mild ache along the inside of your shin after a long run. Now you can barely limp along the pool deck without pain. Or maybe your leg tightens up after 2 miles into your runs. At first the feeling was an annoyance, but now things have progressed to the point that you can barely lift your foot up after 5K.  The pain is so intense you are forced to stop. Your symptoms quickly improve, but on your next run it’s the same thing. You change your shoes, try a yoga class, adjust your bike, but nothing is helping! What should you do next? 

If exercise-related leg pain is interfering with your ability to train and compete, seeking advice from a sports medicine expert is essential. There are multiple causes of leg pain in the athlete including (but not limited to):

  1. bone stress injury
  2. muscle/tendon strain
  3. chronic exertional compartment syndrome (CECS)
  4. vascular issues such as popliteal artery entrapment syndrome (PAES), deep vein thrombosis (DVT), and external iliac artery endofibrosis (EIAE)
  5. nerve entrapment syndromes. A careful evaluation is required to ensure a quick diagnosis and appropriate treatment plan.

I’ve seen athletes struggle for months because of a missed diagnosis despite seeing multiple providers. You should seek out a physician with experience in treating athletes with exercise related leg pain and the ability to perform and interpret diagnostic tests such as MRI, compartment pressure testing, and vascular studies. 

The evaluation should begin with a thorough clinical history. Most exercise-related leg pain is from overzealous bump in training load with an increase in intensity or duration of training faster than the body is able to adapt. This training stress can cause muscle and tendon overload or bone stress injuries ranging from “shin splints” (also referred to as medial tibial stress syndrome) to a complete stress fracture (broken bone!). It’s not all about miles, either. Adding in speed work or lots of hilly terrain also increases the intensity of training even if miles and training time are constant.

Supplemental work in the gym with weights should be an important part of every triathletes training plan. Weight training can actually decrease your risk of developing a stress fracture. However, recognize that high intensity training in the gym with exercises like box jumps (plyometrics) and Olympic lifts can also put a lot of stress on the legs that you may not be accustom to. Any new training stress needs to be added in a thoughtful and progressive manner, allowing time for the body to adapt. Come to your appointment prepared to discuss your training over the past several months in detail.

Nutrition plays a key role in your body’s ability to handle high training loads. Your sports medicine physician will likely ask detailed questions about your diet and may even refer you to a nutritionist. If you are a female triathlete, don’t be surprised if you physician asks you questions about your menstrual cycle as well. Menstrual history can provide helpful information about your total energy availability and may help in identifying risk factors for injury.

After discussing your history in detail, a physical examination will be performed. Bone stress injuries have classic physical examination findings including tenderness along the shin and pain when hopping up and down on the painful leg. Depending on the location and severity of pain, an X-ray and/or MRI may be recommended to provide further detail on the severity of the injury and help determine how long it will take to heal. Overall assessment of your bone health with a DEXA scan may be recommended in some individuals. The physical examination is often normal at rest for most of the other diagnoses listed above, so your physician may ask you to run so you can be examined while you are symptomatic. This type of “provoked” examination may also include measuring compartment pressures or blood flow before and after exercise or performing a diagnostic ultrasound to evaluate for nerve entrapment. 

Treatment of exercise-related leg pain will vary based on the etiology. The most common causes of exercise-related leg pain are bone stress injury and muscle/tendon overload. These conditions typically respond well to modifications in training and occasionally equipment (shoes, bike fit, etc). It may be recommended that you work with a physical therapist or have a formal gait evaluation. For the other less common diagnoses (such as CECS or PAES), treatment options may include discussion of surgery. Since the treatment depends on the cause of pain, it is important to establish the diagnosis early and have a good understanding of what treatments are appropriate and what you can expect regarding time away from triathlon. 

In summary, exercise-related leg pain is extremely common among all levels of triathlete and the list of potential diagnoses is long. Any complaints that are not improving with a brief period of training modification should be evaluated by a sports medicine physician with expertise in evaluation and management of these conditions. Establishing a timely diagnosis and treatment plan will get you back to sport as soon and safely as possible. 

Mederic M. Hall, MD is an Associate Professor in the Department of Orthopedics & Rehabilitation at the University of Iowa and is the Director of Musculoskeletal and Sports Ultrasound for UI Sports Medicine ( He is a team physician for USA Triathlon, the US Ski Team, and the University of Iowa Hawkeyes. He is on the Board of Directors for the American Medical Society for Sports Medicine. 

Triathlon Medical Corner editor: Andrew Getzin, MD is the head team physician for USA triathlon. He is a USA Triathlon level I coach, multiple-time USA Triathlon All-American and has competed in Kona. He is a fellow of the American College of Sports Medicine.  Dr. Getzin is the medical director of Cayuga Medical Center Sports Medicine and Athletic Performance in Ithaca, NY, and the director of their shortness of breath in the athlete clinic,

The views expressed in this article are the opinion of the author and not necessarily the practices of USA Triathlon. Before starting any new diet or exercise program, you should check with your physician and/or coach.