Because you won’t stop stretching them. Many people who have consistent hip flexor tightness would be a lot better off if they just stopped stretching them. This often provides only a temporary relief, giving just a small window of comfort. And guess what? The more you stretch them, the shorter that window of relief becomes, until you’re at the point where you’re stretching them multiple times a day for a long duration just to feel good! That’s no way to live!
A sedentary lifestyle can lead to having weak and tight hip flexors as they are always in the shortened position. Tight hip flexors can lead to a limited range of motion, poor posture, lower back and hip pain, and even injuries. These muscles need to get a workout when you are standing and doing movements such as raising your leg to climb stairs, run, or ride a bicycle.