The Talk Test.....and nasal breathing

For my own purposes I just wanted to gather some links on the use of the "talk test" and nasal breathing as methods of ensuring that exercise remains aerobic / predominantly burning fat.  (A key source for these ideas is Phil Maffetone - check his articles here and particularly  What it means to be aerobic,   Want Speed Slow Down and Healthy Hiking)

{ I need to add context here to avoid confusing you.  I am writing a magazine article about pacing for hillwalking, where you have to go out and walk for 5-10 hours. You need to stay aerobic, burning predominantly fat or else the limited glycogen will be exhausted. I am recommending keeping to a moderate pace as dictated by the talk test or nasal breathing to stay in that aerobic zone.

This is not about weight loss or fat loss or whatever.   And there are also other approaches like training fasted which could be used although my piece is a bit more generalist.  I also think that HIIT / tabata can effect changes to the muscle cells which mean you can remain aerobic at higher intensities, but that is a different subject}

Talk Test

1. Talk Test and Ventilatory Threshold - PERSINGER, R., C. FOSTER, M. GIBSON, D. C. W. FATER, and J. P. PORCARI. Consistency of the Talk Test for Exercise Prescription. Med. Sci. Sports Exerc., Vol. 36, No. 9, 
2. COMPARISON OF THE COUNTING TALK TEST AND HEART RATE RESERVE 
3.  The Talk Test and its relationship with the ventilatory and lactate thresholds.

• Rethinking the talk test
• Sweat Science on the talk test

 Nasal Breathing

Matt Metzgar on nasal breathing for running:

Next, I found this article where a coach prescribes long, aerobic barefoot runs with nasal breathing as a complete training program.  There are also a couple of related articles by the author at this website that are of interest.  The author believes that nasal breathing is a major key to keeping the heart rate down, which will make a run truly aerobic.

From here: 

When you work out aerobically, of course, the whole point is to find ways to get more health benefits from your workout. Here are some questions you might ask yourself. Would you like to burn more fat during your workout? Would you like to reduce exercise-related fatigue and injury? Would you like to increase your endurance and stamina? Would you like your aerobic workout to help improve your breathing?

If your answer is "yes" to any or all of these questions, and it no doubt is, then there is one simple thing you can do: don't let yourself become "breathless" at any point during your workout. When you become breathless, you undermine your breathing coordination, burn sugar instead of fat for fuel, become tight and tense (which can promote injury), and, in general, undermine your endurance and stamina.

The simplest way to know whether you are exercising too intensely and becoming breathless is to try to speak several sentences out loud while you're working out. If you can't do it without gasping for breath, then your workout is no longer "aerobic"--it is, or is about to become, "anaerobic," which means that it is proceeding without oxygen and you are no longer burning fat for fuel. Another way to look at what has happened is that you are hyperventilating, which means that you won't get oxygen where it needed in your brain and body and you will feel as though you are out of breath, even though you may have plenty of oxygen in your blood.

A simple way to ensure that you are working out at a level that will not make you breathless is to inhale and exhale only through your nose. If you try this you will quickly discover, especially at the beginning, that you will have to work at a slower or less-intense rate during your workout. Gradually, however, your breathing coordination and blood chemistry will improve and you will be able to do more and progress more rapidly, eventually going well beyond your previous limits. You can also, if you wish, breathe out slowly through pursed lips, as I already mentioned.

Nose breathing technique will limit you to running at the top level of your aerobic zone which is about 80% of your maximum heart rate and the most efficient level to do most of your training at for distance running.