Boxed breathing therapy works too.
The SEALS rehearse it, probably as a diving regimine.
A SEAL nap is also effective.
The boxed breathing is a 10 minute cycle.
The nap is timed for 25 minutes with legs elevated.
I do these 3 to 4 times per week. It feels beneficial.
Can you describe the details of boxed boxed breathing. Does a seal nap consist of just laying down with your legs elevated for 25 minutes. Or is there more to it?