A common problem with people who engage mostly in running or other 'forward motion' activities without doing a lot of strengthening and stretching of other muscles groups in the leg is that they can create an imbalance between muscle groups. The most common form of this is called piriformis syndrome, in which the piriformis muscle on the inside of the thigh is very strong and not balanced by the gluteal (bottom) muscles. The result can be that the nerve that runs through the piriformis, called the sciatic nerve, can be compressed which can lead to nerve pain. The solution to this problem is to stretch out the piriformis while at the same time performing lateral motions of the leg and other exercise to strengthen the gluteal and other hip adductors. Your personal trainer can develop this exercise program for you, which should resolve your problem quickly. As always the diagnosis and the management of your particular condition will require a physical examination by your personal physician. Setting up a visit with a sports medicine doctor
might be particularly beneficial.