Adaptive 12-session plan, in phases
Start at your level: beginner, intermediate or advanced. Each phase is 12 sessions. When you complete one, the next is built from how your recent holds went.
Breath-hold training app for iPhone
Want to hold your breath longer?
ZenDepth is a dry-land training app for freedivers and spearfishers. It builds a 12-session plan around your current hold, then guides you through CO₂ tables, O₂ tables, open holds and stretching, one session at a time.
Phase 1 is free.
No payment needed to start.
Dry-land training only. Never in or near water, never alone. Read the safety note
How it works
A plan that starts where you are.
-
01
Set your baseline
Do a calibration hold or enter your personal best. ZenDepth uses it to size every table.
-
02
Train the plan
Each phase is 12 sessions mixing CO₂ tables, O₂ tables, stretching and open holds, with voice cues and haptics through every round.
-
03
Move up a phase
Finish all 12 sessions and your next phase is generated from your recent hold data.
What's inside
More than a table timer.
A guided path with adaptive phases, technique cards and stretching, plus friends to train alongside.
CO₂ and O₂ tables
Generated from your personal best. CO₂ tables keep the hold steady while rest shortens. O₂ tables keep rest steady while holds build. Tap to log contractions as you go.
Open holds with live Apple Watch heart rate
Count-up holds that end whenever you tap. With Premium and an Apple Watch, see your heart rate live during open holds and review it on a chart afterwards.
Guided stretching library
Five guided stretches for the chest, rib cage and diaphragm, with timed rounds you can do on their own or as part of your plan.
Unlockable technique cards
Twenty technique cards unlock as you train, starting with recovery breathing, belly breathing and contraction tracking. Each explains why it works and how to practise it.
Progress chart
Every hold lands on your hold-history chart. Drag across it to revisit any hold and see your trend over time.
The Surface
Add friends, compare max holds and training time on your friends leaderboard, and send O₂ reactions to each other's holds.
Safety first
Train on dry land. Never alone.
- Dry land only. Never practise breath holds in or near water: not in a pool, the sea, a bath or a shower.
- Sit or lie down somewhere safe. Never while driving, cycling, standing or operating anything.
- Never alone. Have someone nearby who knows what you're doing. Blackout can happen without warning.
- Don't hyperventilate. Breathe calmly before a hold. Stop and breathe if you feel dizzy, tingly, confused or unwell.
- Check with a doctor first if you have a heart, lung or blood-pressure condition, epilepsy or a history of fainting, or are pregnant.
In-water freediving needs a proper course and a trained buddy watching you. ZenDepth is for the training you do on land.
For schools & instructors
Students who keep training between courses.
Give your students a structured dry-training plan for the weeks after their course, so they come back prepared.
Email us about partnering-
3 months of Premium, free
We give your school free codes for 3 months of Premium. Hand one to each student at the end of their course.
-
Partner revenue share
If students stay on after the free period, you share in what they pay.
-
Founding-partner perks
A feature on our Instagram, and a say in what we build next, including an instructor view now in development.
- ZenDepth is iPhone-only today.
Built by a freediver
Made for the training between dives.
ZenDepth began as the app its maker wanted for dry training between freediving sessions: guided rather than clinical, social rather than solitary, and more than a timer.
It's easy to navigate, provides comfort, and has helped me relax and work on my goals. A really positive and supportive experience overall.
Pricing
Phase 1 is free.
Your first 12-session phase, manual drills, the stretching library and The Surface cost nothing. Premium unlocks every phase after that, plus live Apple Watch heart rate.
Best value
Yearly
$19.99
per year, auto-renews
About $1.67 a month. Save 58% vs monthly.
Get startedUS prices. Purchases are made in the app through Apple. Subscriptions auto-renew until cancelled; manage or cancel anytime in iOS Settings.