How to use the Plank Timer
- Choose the plank type and goal time, and enter your weight for the calorie estimate.
- Start the camera and place it about 2 m to your side, 30–60 cm off the floor, with head to feet visible.
- Get into position and the timer starts automatically. Adjust when you see a sagging or piked warning; timing resumes once form is restored.
- Stand up or press stop, then save the result to see your personal best and recent records.
How is good form detected?
The AI finds your shoulders, hips and ankles, then measures how far the hips sit from the shoulder–ankle line relative to body length, plus the shoulder–hip–ankle angle. Near 180° with little offset counts as good; hips well below the line means sagging, well above means piking. It also checks that your body is close to horizontal so standing is not mistaken for a plank.
Why only count good-form time?
A plank works because your core stays braced. Sagging shifts load to the lower back and piking lets the abs off the hook. Many people hold on long after their form breaks, and that time adds little while risking back strain. Automatic pausing shows how much of your plank really counts.
How long should beginners hold?
A common starting point is 3–5 sets of 20–30 seconds with good form, building toward 60 seconds or more. Several clean sets beat one long, sloppy hold. Everyone is different: stay pain-free and keep good form.
Calorie estimate
Planking is moderate body-weight exercise at about 3.8 MET: kcal = 3.8 × 3.5 × weight ÷ 200 × minutes. A 60 kg person burns about 4 kcal per minute; the number is only a reference.
Frequently asked questions
Does it support side planks?
Yes. Choose “Side plank” and face the camera; the AI checks that shoulders, hips and ankles stay in line.
Why doesn’t the timer start?
Make sure the camera sees you side-on, your whole body is in frame and you are close to horizontal. A camera placed too high makes your body look diagonal; lower it toward the floor.
Are high (straight-arm) and forearm planks both supported?
Yes. Only the line of the torso and legs is checked, not the arm position.
Where are my results stored?
Only in this browser’s local storage. Clearing browser data removes them; nothing is uploaded.
Is it OK with back problems?
If you have a herniated disc or similar condition, ask a doctor or physiotherapist first. The tool only flags obvious form errors and cannot judge whether the exercise suits you.