How to do the hip flexor stretch
From a half-kneeling position (one knee down, one foot forward), tuck your pelvis and shift your weight gently forward until you feel a stretch at the front of the hip of the kneeling leg. Keep the torso upright.
How long to hold it
The most common recommendation for a static hip flexor stretch is 45 seconds per side, repeated 2 times, with a short break to switch sides. That is exactly how this timer is pre-configured: press start and it counts every hold, tells you when to switch sides with a distinct sound, and gives you 30 seconds of rest after the final rep. Your eyes never leave the floor.
Common mistakes
Arching the lower back instead of tucking the pelvis (this fakes the range), lunging too far forward, and letting the front knee collapse inward.
Why it's worth doing
Hip flexors adapt to every hour you sit. Opening them restores hip extension for walking and running, and is one of the most common physio prescriptions for anterior pelvic tilt.
About this timer
ExtendTimer is a free stretching timer with sound cues for every phase: a steady tick while you hold, a count-in when you switch sides, and an alert on your final rep. It works offline, installs to your home screen like an app, and needs no account. Routines of up to two stretches are free forever; Pro ($4.99/month or $29.99/year) unlocks unlimited routines and the full sound studio.