Pain in the groin while running is a common but complex issue for athletes. The groin is crowded with muscles, tendons, ligaments, and nerves, making it challenging to pinpoint the exact source of discomfort. Understanding the differences between muscular strains and more serious structural issues is the first step toward safe and effective recovery.
The Most Common Muscular Causes
The majority of groin pain in runners stems from soft tissue injuries, primarily affecting the adductor group and the hip flexors. Adductor muscles run along the inner thigh, with the adductor longus being the most commonly injured muscle. These muscles stabilize the legs and bring them together, and they can be strained by overuse, a sudden increase in training intensity, or insufficient warm-up.
Adductor-related pain often presents as localized tenderness that worsens during activities like squeezing the legs together or pushing off during the running stride. While discomfort may begin subtly, it typically returns with greater intensity after the activity is finished. Tendinopathy, a chronic issue affecting the tendon, can develop gradually over weeks or months, often presenting as a deep, dull ache.
Hip flexors, including the iliopsoas muscle, are also frequent sites of injury because they perform the repetitive action of lifting the knee during running. A strain or tendinopathy in the hip flexors causes pain at the front of the hip that is aggravated by resisted hip flexion. These injuries occur when the tissue is suddenly overstretched or overloaded. Biomechanical imbalances, such as weak gluteal or core muscles, often force the hip flexors and adductors to work harder to stabilize the pelvis.
Structural and Skeletal Contributors
Groin pain that is not purely muscular often points to a structural or skeletal issue that requires careful diagnosis.
Athletic Pubalgia
One distinct condition is Athletic Pubalgia, often referred to as a “sports hernia.” This is not a true hernia but a soft tissue injury involving a strain or tear of the muscles and tendons in the lower abdominal wall, frequently where the oblique muscles attach to the pubic bone. Athletic pubalgia causes severe pain in the groin, especially with movements that increase intra-abdominal pressure, such as sprinting, twisting, or performing a sit-up against resistance. The pain typically improves with rest but flares up immediately upon returning to vigorous activity, and unlike a true hernia, it does not produce a visible bulge.
A true Inguinal Hernia, by contrast, is a structural defect where abdominal tissue protrudes through a weak spot in the abdominal wall. This creates a palpable lump that may become more noticeable with coughing or straining.
Stress Fractures
Stress Fractures, particularly those affecting the femoral neck or pelvis, result from repetitive mechanical loads overwhelming the bone’s ability to repair itself. This type of injury often begins as an insidious onset of groin or thigh pain that worsens with weight-bearing activities and may radiate toward the knee. If the injury progresses, the pain can become constant, occurring even at rest or at night, and may make normal walking difficult. A stress fracture of the femoral neck warrants immediate medical attention because of the risk of complete bone failure.
Immediate Steps and Medical Red Flags
When groin pain begins during a run, the immediate step is to stop the activity to prevent further injury. Initial self-care involves temporary rest, applying ice to the painful area, and avoiding movements that provoke discomfort. During the acute phase, the focus must be on recognizing “red flags” that indicate a potentially serious condition requiring immediate professional medical evaluation.
A severe, sudden, or stabbing pain that makes it impossible to bear weight on the leg is a red flag. Pain accompanied by systemic symptoms, such as an unexplained fever, chills, or nausea, also warrants urgent medical assessment. Any pain involving the testicles, or the presence of a new, painful, or tender lump in the groin area, should be promptly checked by a physician to rule out conditions like a complicated hernia or testicular torsion. Pain that continues to worsen despite a few days of rest suggests the injury is more severe than a minor muscle strain.
Rehabilitation and Safe Return to Running
Once a diagnosis is established and the acute pain phase has passed, rehabilitation focuses on restoring the tissue’s capacity to handle the stresses of running. Physical therapy is important in this phase, not just for treating the injury, but for identifying and correcting underlying biomechanical weaknesses. Therapists commonly target weakness in the gluteal and core muscles, which, if insufficient, place excessive strain on the adductors and hip flexors.
The core principle of rehabilitation is progressive loading, which involves gradually increasing the force applied to the injured muscles, tendons, or bone. This typically begins with low-load exercises, like isometrics, which strengthen the tissue without excessive movement, and slowly advances to heavier resistance training and then to sport-specific movements. For adductor injuries, strengthening protocols that specifically target hip-adductor strength have shown the highest level of evidence for effective recovery.
A safe return to running must be guided by pain-free movement, meaning the athlete should not experience pain greater than a mild, tolerable level during or after the activity. Runners should reintroduce activity using a walk-jog progression, closely monitoring their training load, and adhering to the 10% rule—never increasing weekly mileage by more than ten percent. The rehabilitation program should also incorporate exercises that improve balance, coordination, and plyometrics to ensure the hip and core can handle the dynamic forces inherent in running and prevent re-injury.