The following stretches should be done 5-6 days per week, ideally after your body is warmed up for the best gain in tissue mobility.
Note: The rate of flexibility gains will depend on your body type, age, the quality of time you spend stretching, and how much you move during the day.
Kneeling Hip Flexor Stretch: 1 minute (each side). Start in a kneeling position with one knee up and the other leg down. Before you stretch, engage your abdominals and maintain a posterior pelvic tilt by bringing your belly button up (see the video below for reference). To increase the stretch further, engage your glutes. You may feel a stretch on the kneeling limb.
Stretch 2:
Hip Flexor Stretch (Active): 3 x 30 seconds (each side). Standing upright with your feet shoulder-width apart, step forward into a mini lunge, keeping your back leg straight. As you go forward, keep your torso upright while maintaining a posterior pelvic tilt (see the video below for reference). For added stretch, bring your hands overhead. Hold for a few seconds then switch to the other side. You should feel a stretch in the front part of your thigh on the trailing limb.