Sit-up: Proper Form, Benefits & How Fit Play Counts It
A classic ab exercise. From lying flat, curl your whole torso up toward your knees, then lower back down with control. One lie → up → lie cycle is a rep.
Category: Core · Type: Reps · Default goal: 15 reps
Benefits 💪
- Strengthens the abdominal muscles
- Improves core control
- Supports better posture
How to do it ✅
1) Lie on your back with knees bent, feet flat.
2) Curl your torso all the way up toward your knees.
3) Lower back down with control.
4) Keep the movement smooth — avoid yanking your neck.
How Fit Play counts the Sit-up 📱
Fit Play tracks the position and angles of joints such as your shoulders, hips, and knees in real time. One rep is counted each time you complete a full cycle from the start position to the end position shown above and back again, and it is announced by voice and a beep. If the movement is not completed, the count does not go up.
Joint angles read from the "Lie back" sample photo: knee about 66°, hip about 124°, elbow about 94°.
Joint angles read from the "Up" sample photo: knee about 66°, hip about 41°, elbow about 56°.
These come from a single photo, so they vary with body proportions and camera angle.
Recognition is most stable when the phone stands upright 2–3 meters away and your whole body, head to toe, is in the frame.
Related guides 🔗
Fit Play Exercise Guide - All 10 Bodyweight Exercises at a Glance
Browse all 10 bodyweight exercises by body area, each with the skeleton recognized by the app.
Fit Play - Auto Counter & Log
A home workout app that recognizes your movement with the camera and counts reps and hold time automatically. Run through 10 bodyweight exercises and routines — squats, push-ups, planks, and more — completely hands-free.
Frequently Asked Questions (FAQ)
How does Fit Play count the Sit-up?
It tracks the position and angles of your joints with the camera and counts one rep for each full cycle from the start position to the end position and back. Reps are read aloud.
How many reps should I start with?
The default goal in Fit Play is 15 reps. You can adjust it to your level, so start with what you can do with good form and build up gradually.
Do I need equipment for the Sit-up?
No. It is a bodyweight exercise, so a mat is all you need to do it at home.