8. Hamstring strain

Description: A strain of one of the hamstring muscles located at the back of the thigh, which often occurs during an explosive activity such as sprinting, when the hamstrings are suddenly put under extreme load. A hamstring strain is more likely to occur in the early stages of a run or when the muscle hasn't been warmed up sufficiently.

Treatment: Rest and ice to reduce inflammation, and follow this with a progressive programme of flexibility training and strengthening exercises under the guidance of a sports therapist.

Training and racing: Hamstring injuries can become chronic if you try to return to running too soon, so it is important to maintain treatment until your therapist advises that you can resume training. Until you can resume your running, maintain your fitness by swimming instead.