Objective: To compare the immediate. short term and long term effects of active isolated stretch versus post isometric relaxation on hamstring flexibility in young healthy adults. Study Design: Randomized controlled trial (trail number is NCT04024839). Place and Duration of Study: Islamabad Federal College. https://www.ealisboa.com/great-pick-BERKLEY-POWER-WORM-7-100-PACK-super-buy/