How to do the hamstring stretch
Sit on the floor with one leg extended and the other bent. Hinge forward from the hips, reaching toward your toes while keeping your back long. You should feel a pull along the back of the extended thigh, not behind the knee.
How long to hold it
The most common recommendation for a static hamstring stretch is 30 seconds per side, repeated 4 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
Rounding the back to reach further (hinge from the hips instead), bouncing during the hold, and locking the knee so hard the pull sits behind the joint.
Why it's worth doing
Tight hamstrings pull on the pelvis and are a common contributor to lower back discomfort. Regular holds improve forward-bend range and make squats, running and deadlifts feel smoother. Runners and cyclists in particular tend to carry chronic hamstring tightness from repetitive, shortened-range movement — a few minutes a day of static holds is enough to keep it in check.
Variations
Seated (main version): best for control and keeping the back flat. Standing forward fold: hinge from the hips with a soft knee bend, letting your head and arms hang — good as a quick reset between desk sessions. Reclined with a strap: lie on your back, loop a towel or strap around one foot, and draw the leg toward the ceiling — the most lower-back-friendly version if seated forward folds bother your spine.
Who should be careful
Stop if you feel sharp or shooting pain, numbness, or tingling down the leg — that can indicate nerve involvement (sciatica) rather than a normal stretch sensation, and pushing through it can make things worse. A normal hamstring stretch feels like a steady pull in the belly of the muscle, not a pinch behind the knee or a burning line down the leg.
FAQ
How long should I hold a hamstring stretch? A common recommendation is 30 seconds per side, repeated 4 times. This timer's hamstring preset uses exactly these numbers and counts every phase for you.
What muscles does the hamstring stretch target? Primarily the back of your thigh — the hamstring group runs from the sit bones to just below the knee.
Should I stretch hamstrings before or after running? Save static holds like this one for after your run or workout, when muscles are warm. Before exercise, a few reps of dynamic movement (like leg swings) prepares the muscle better than a long static hold.
Related stretches
Calf Stretch Timer · Back Stretch Timer · Hip Flexor Stretch Timer · Quick 5-Minute Full-Body Routine
Want the anatomy and the "why"? Read the Hamstrings muscle guide.
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. Create a free account and it also tracks every session — total minutes stretched, your most-worked muscles on a visual front/back body map, and saved routines — so you can see your consistency build up over time, not just complete one session and forget it. Routines of up to two stretches are free forever; Pro ($4.99/month or $29.99/year) unlocks unlimited routines, custom recorded sounds for any phase, and curated multi-stretch routine presets.