Hi

I think to be on the safe side you need to rule out a couple of things. Your symptoms (especially seeing as they haven't improved with stretching etc) could be related to a hip joint problem. You can get a synovitis of the hip joint which is basically inflammation of the joint or bursitis which is also an inflammatory condition affecting the bursa (fat pad) around the hip. Given the fact that you are a distance runner and engaged in sprint training which is unfamiliar to you a hip joint problem is quite feasable as they tend to manifest themselves after a period of altered use or prolonged use!! You can also get stress fractures in and around your hip so I think it is probably wise to see someone and rule out the possibility that there is something else going on other than a groin strain.

If it does turn out to be a straight forward groin strain - they can be tricky to resolve. A really good stretching and strengthening programme is vital! There is an active training programme documented by Homisch et al in a study published in the Lancet. Sorry - I don't have a link to this article but you could try searching online to see if you can track it down.

Hope this helps.

Rachael
Rehabilitate prevent perform physiofixme