Google stress fracture -
Stress fractures are much more likely to develop in people who have just started a new exercise or abruptly stepped up the intensity of their workout. When the muscles aren't conditioned, they tire easily and can't support and cushion the bones as well. Increased pressure is exerted directly on the bones, which can lead to a fracture. Boots
Stress fractures often are the result of increasing the amount or intensity of an activity too rapidly. Orthoinfo
stress fractures – a tiny crack that develops in a bone as a result of repeated stresses (for example, overuse during high-impact activities like distance running). Resting the affected body part will heal most stress fractures. NHS
A stress fracture is a small crack in a bone caused by overuse and high impact. A stress fracture results from repetitive use injuries that exceed the ability of the bone to repair itself. Orthosurgery
followed by:
'Treatment
Stress fractures heal with time and rest. Athletes are advised to rest from any activity that caused the stress fracture for the 6-14 weeks that the fractures take to heal (ask your doctor how long your particular fracture will probably take to heal), or until pain-free for 2-3 weeks. If activity is resumed too quickly, a larger stress fracture may develop, the original stress fracture may never heal, and athletes are at risk for re-injury. Activities of daily living and limited walking are permitted.
PREVENTION
High-impact exercises should be increased gradually (not more than 10% per week).'
This is an injury caused by overtraining / performing.
