Building Physical Capacity

The window of tolerance

Everyone has a range of activation they can hold while staying present and thoughtful. Researchers call this the window of tolerance. When something activates you, a wider window means the same event may not push you into fight, flight, or freeze, and a narrower window means it may.

Many of the practices in this course help in the moment. This one works on the container itself, through the body's physiology. It is related to the idea of raising the banks of the river, which comes up in a later segment.

The practice: a simple exhale test

This test gives a rough sense of how sensitive your body's breathing alarm is, often called CO2 tolerance. A shorter time may mean the alarm goes off sooner, and a longer time may mean you can stay with the sensation of wanting more air for longer. The test is borrowed from the work of Andrew Huberman. It is not a competition, and a number is just a place to start. Have a stopwatch ready, such as the one on your phone.

• Sit or lie down comfortably and breathe normally through the nose for four or five breaths
• Take one deep inhale through the nose until the lungs and belly are full
• Start the stopwatch and begin a slow, smooth exhale, as if through a tiny straw. Do not hold your breath
• When your lungs are completely empty, stop the stopwatch and note the time

First thing in the morning is a good time to test, but any time is fine for the first try.

What your time suggests

• Under 25 seconds is a shorter exhale time. This does not mean you did poorly. It describes where your body is today.
• 25 to 45 seconds is moderate.
• Over 45 seconds is a longer exhale time.

Box breathing to build capacity

Box breathing uses four equal sides: breathe in, hold, breathe out, hold. Choose a count based on your result:

• Shorter exhale time: three seconds per side
• Moderate: five or six seconds per side
• Longer: eight to ten seconds per side

A common suggestion is to practice two or three times a week for a few weeks, then repeat the test to see whether anything has changed. Choose a count that stretches you a little without causing stress. If counts feel strained, go back to a shorter count.

Safety

Stop if you feel lightheaded or unwell, and return to normal breathing. If you have a respiratory or heart condition, or if focusing on your breath tends to increase your anxiety, check with a health professional before trying breath practices like these. The other practices in the course use touch, vision, and movement, and may fit better.

Why bother with a number

Many of the practices in this course are hard to measure. This one gives you something you can check over time. It does not measure your worth or your progress as a person. It is simply one tangible way to see whether the work you are doing on the body is making a difference.