Runners with longer strides at the end of the run had stronger hamstrings. This suggests that strength in the hamstrings helps to maintain a full stride even when an athlete is tiring, supporting the idea that strength can help delay fatigue. - pponline.co.uk
I've already covered a couple of different ways to eccentrically strengthen your hamstrings here- this article offers a couple of more ideas.
1. Lie on your back with your feet hip width apart and the soles of your feet on an 18” bench or step.
2. Push down into the bench with your feet lifting your hips up high. You will feel your hamstrings working. Do not lift your shoulders or neck off the floor and keep your upper back flat down.
3. Lower the hips back down until your bottom is just off the floor, then push down into the bench again.
4. Continue for 15 repetitions, rest for 45 seconds, then complete two more sets.
Once you can do 3 x 20, progress to one-legged hamstring hip lifts on the bench. Start with 3 x 10 and build up to 3 x 20.
Once you can do the one-leg lifts on the bench, progress to using the Swiss ball.
Place two feet on the Swiss ball, as you did on the bench, and complete the exercise using the same technique. The instability of the ball automatically makes it harder.
Build up to completing 3 sets of 20 reps of one-leg hamstring hip lifts on the Swiss ball. I recommend that all good runners should be strong enough to do this.