When an injury sidelines adiehard runner, chances are the culprit is one of the Big Five: shin splints, Achilles tendonitis, plantar fasciitis, iliotibial band syndrome or cartilage damage - the dreaded runner's knee.
Injuries hobble 40 to 50 per cent of runners on an annual basis, according to a 2010 study published in Current Sports Medicine Report. Researchers found that the only proven prevention strategy is to reduce weekly mileage.
The bad news? Besides the Big Five, myriad other insidious conditions can get in the way of a runner's high, including these four.
DEAD BUTT SYNDROME
Say what? That's the catchy term, popularized by New York Times blogger Jen A. Miller, for inflammation of the tendons in the gluteus medius, one of three large muscles in the rear.
Anatomically speaking: The gluteus muscles help stabilize the hips and the pelvis. Weak glutes - common in runners who don't cross-train - overburden smaller muscles around the hip. When inflammation and scar tissue develop in the gluteus medius, runners unconsciously adapt by changing their strides, which may lead to a domino effect of injuries to the hamstrings, Achilles tendons, knees and calves.
Symptoms: Sharp pain in the hip, discomfort sitting for long periods.
Next step? Cut back on running until you get assessed by a sports medicine specialist who can recommend strengthening exercises for the gluteus muscles and lower abdominals. Try deep tissue massage to break up scar tissue and increase blood flow to your glutes. Then get off your butt and start cross-training.
Say what? Pounding the pavement damages red blood cells, which may lead to "footstrike anemia" originally diagnosed in marching soldiers. Unlike anemia found in athletes who eat an iron-deficient diet, footstrike anemia may not improve with iron supplementation.
Medically speaking: Running compresses tiny capillaries in the feet, causing red blood cell fragmentation. Depending on the frequency and severity of foot-pounding, this may result in hemolytic anemia - too few red cells in the blood. Compounding the problem, distance running increases blood plasma volume, which dilutes the red cells. Jagged red cell fragments in the blood smear of an otherwise healthy endurance runner may indicate it's an exercise-related form of anemia.
Symptoms: Fatigue, shortness of breath, sensitivity to cold.
Next step? Get tested to rule out iron deficiency and other types of anemia. Ask your doctor about footstrike anemia, which is under-diagnosed. Train on softer ground, using well-cushioned shoes, and run like Fred Astaire - staylight on your feet.
Say what? Just like it sounds, this injury involves a snapping sound or sensation around the hip joint. A clicking feeling on the outside of the hip doesn't usually hurt, but persistent snapping on the inside can be annoyingly painful.
Anatomically speaking: In a lateral (outside) snapping hip, muscle fibres of the gluteus maximus or tensor fascia lata of the thigh flick across the bony head of the upper thigh bone. An internal snapping hip is caused by the iliopsoas tendon as it catches on the front of the pelvis. Either type may be due to biomechanical quirks or repetitive overuse.
Symptoms: All that hip snapping and clicking as you run or walk.
Next step? Ease off on training and stretch muscles in the area, including the hip abductor and hip flexor. Get a running coach to check your stride. If that doesn't help, a sports injury specialist may recommend soft-tissue therapy (myofascial release) or, in the worst-case scenario, surgical release of the iliopsoas tendon.
Say what? We're talking burnout, not the practice of "overreaching" a training limit temporarily for long-term fitness gains. When performance begins to lag, Ironman types tend to push harder, creating a vicious cycle of chronic overtraining.
Medically speaking: Inadequate rest periods combined with excessive training frequency and intensity wreak havoc on the body's hormonal and neurological systems. Markers include decreases in maximum heart rate (the highest rate an individual can safely achieve), urinary output of norepinephrine (a stress hormone) and blood lactate levels (which may indicate a reduction of lactic acid to produce energy). Overtraining thresholds may be difficult to determine since they depend on individual makeup, and change as the runner's fitness level increases.
Symptoms: Persistent muscle soreness, sinusitis, frequent illness, mood swings, disturbed sleep.
Next step? Hang up your running shoes for a week and get lots of sleep. When you start running again, build up mileage gradually. Keep a training journal to monitor your energy levels and track your overtraining threshold as it rises. If your buddies suggest that you might be in denial about overdoing it, think about getting psychological help.