MODIFIED CO2 TOLERANCE TEST

The Modified CO2 Tolerance Test (also known as the Exhale Control & Hold Capacity Test) is a respiratory test developed by Dr. Justin Ternes. It is based on the well-known CO2 Tolerance Test created by Brian Mackenzie - with a few modifications aimed at improving the reliability and validity of the popular CO2 Tolerance Test.

Continue to see step-by-step instructions, a video tutorial, and a way to record your results.

SIMPLE INSTRUCTIONS
1. TAKE 3 DEEP BREATHS TO PREP
2. DEEP BREATH IN… START TIMER… EXHALE AS LONG AS YOU CAN
3. PUSH “LAP” WHEN YOU CAN’T EXHALE ANY MORE
4. HOLD YOUR BREATH AT THE BOTTOM AS LONG AS YOU CAN
5. STOP TIMER WHEN YOU NEED TO BREATHE
6. RECORD YOUR TIME

GOAL: PERFORM 3 TIMES AND SEE IF YOU CAN INCREASE YOUR TIME BY 10 - 20 SECONDS EACH TIME.

BREATH CONTROL TIPS

  • Hold your palm approx. 6 inches from your mouth and blow just barely enough to feel the stream of air on the palm of your hand.

  • Visualize blowing a candle just enough to make it flicker.

  • Round your spine and contract your abs as you get to the end of your exhale.

VARIABLES THAT INFLUENCE YOUR TIME:

Quality of sleep, fatigue, full or empty stomach, distracted, time of day, location, etc.

HOW TO RECORD YOUR TIME:
(Exhale Time) + (Hold Time) = Total Time

Ex: You exhaled for 42 seconds, held for an additional 12, total of 54 secons.
Your documentation will look like - 0:42 / 0:12 = 0:54

VIDEO INSTRUCTIONS FOR THE MODIFIED CO2 TOLERANCE TEST

1. Take 3 Full Breaths

2. Take a 4th Inhale

3. Start Timer & Begin Exhale

4. At End of Exhale, Hold

5. Press "Lap" to Record How Long You Can Hold

6. Stop Timer as Soon as You Need to Breathe

7. Recover and Record Your Time

8. Repeat

How to interpret your results:

Total Time // Ranking
Under 0:30 // Below Average
0:30 to 0:45 // Average
0:45 to 1:00 // Intermediate
1:00 to 1:15 // Advanced
1:15 to 1:30 // Very Advanced
Over 1:30 // Elite

What are we testing:

  • Lung capacity

  • Breath control

  • Nervous system stat

  • Stress levels

  • Skill & familiarity with the test

The Test is the Practice:

The more you perform this test, the more you will improve your lung capacity, improve your breath control, and gain control of your nervous system!

Note: If you consistently get below 30 seconds total, then you may be exhaling too hard and too quickly.

RECORD YOUR RESULTS!

Remember, your results will have three times:
(Exhale Time) + (Hold Time) = Total Time

Example: 33 second exhale, 22 second hold, 55 seconds total
0:33 / 0:22 = 0:55