Stiff-Leg Deadlifts! This is my absolute favorite exercise for a deep burn in my hamstrings. Some of you may not be able to complete the full range of motion at first, but in time you will gradually increase your flexibility as you perform the exercise.
Add 5 sets of 10-12 reps to your next leg routine! I also like to superset stiff-leg deadlifts with a leg curl machine from time to time to an extra deep burn.