Eric T on Nostr: Try "The Tunnel", a simple box breathing exercise to test your CO2 tolerance: inhale, ...

Try "The Tunnel", a simple box breathing exercise to test your CO2 tolerance: inhale, hold, exhale, hold. First cycle 4 seconds, then 5, 6, etc.

How far can you get?

https://exercisetimer.net/workouts/shared/d4dsrv90sz12s0tcjr