Soomlet: CO₂ Breath Hold Timer

Keep your dry breath-hold sessions easy to follow. Soompyo is a CO₂ table timer for freediving practice on dry land, with clear recovery and hold phases, customizable timings and a collection of ocean-inspired themes.

Build your table
• Set the number of rounds, hold duration, initial recovery, recovery decrease and minimum recovery.
• Keep each hold the same length while recovery intervals follow the decrease and minimum you choose.
• Preview the round-by-round schedule and total session time.
• Finish with a 60-second recovery after the last hold.

Follow each phase
• See recovery and hold phases distinguished by both words and color.
• Check the time remaining, current round and upcoming phase.
• Turn sound cues and vibration on or off separately. Vibration requires a supported device.
• Keep the screen awake during a session, with a stop button available throughout.

Review your sessions
• See completed, stopped and interrupted sessions labeled separately.
• Review elapsed time, completed hold intervals and the hold duration you set.
• Keep up to 200 recent records on this device, or clear them all.
• Elapsed time includes recovery and hold phases. Records track the timer, not whether you actually held your breath.

Choose your ocean
Pick from 16 coordinated themes featuring ocean friends and diving characters, including an arctic hare, penguin, dolphin, manta ray and whale. Each theme brings its character, scenery and interface colors together. Choose Korean or English, and keep your theme and language preferences for next time.

Before you start
Use this timer only on dry land. Sit or lie down with a supervisor who can respond to an emergency. Do not hyperventilate. Stop immediately if you feel dizzy or unwell.

The preset times are editable examples, not personal recommendations or a training prescription. Soompyo is a timer; it does not measure your breathing or physical condition.

Soompyo is not a medical device and does not diagnose, treat, cure or prevent any medical condition. For medical advice, diagnosis or treatment, consult a healthcare professional.

Locking the screen or switching apps ends the session. Sessions do not resume automatically. Sound and vibration depend on your device settings. The app contains ads; banner ads are hidden during training.