Hi thereThank you for taking the time to leave a review. The shorts do not need to be a tight fit to work and due to the patented Multi-path technology you should NOT experience any contractions on your legs or thighs, the primary feeling should be on your buttocks initially. From when you start to increase the intensity you should feel a tingling sensation and as you increase it further you will feel a tightening on your buttocks and then once you get to the therapeutic intensity you feel a lifting, tightening in between your legs.I will ensure one of customer care team reach out to you to today, to ensure you are experiencing the above sensations. If for any reason you do not experience these sensations, we will happily arrange a size exchange.Kind regardsChristina