If you have suffered from a pulled hamstring, it is important that you don’t immediately injure yourself again once you return to training. To prevent doing so, make sure that you do appropriate strengthening exercises.
The best exercises to carry out for hamstring a sports injury, are bicycle leg swings. Begin by standing on your left leg only (you may use a wall or other type of support to keep steady). Lift your right knee to waist level until your thigh is parallel with the ground, with your knee being flexed at 90˚ or more.
Now that your thigh is parallel to the ground, straighten your right leg out in front, keeping your thigh parallel with the ground. As your leg becomes fully stretched, drop your leg down and back so that your leg is stretched behind your body. Make sure that your leg is straight and fully extended then bend your right knee and life your right heel towards your bottom. At the same time, move your right knee forward until parallel with the ground.
To start off with, do two sets of 15-30 repetitions on each leg. Increase this over several weeks until you reach 4.-60 repetitions.