N=1: Five Percent

N=1. A sample size of one: you.
You are the test bed. You are the lab rat. The results are your own.
This blog is intended to help you improve your health and performance with information and research on new methods and parameters, and as a ground-zero for getting dirty.
We want to empower you to test things on yourself; to explore the possibilities and extract what works for you and what doesn’t. You may find that adding turmeric is groundbreaking in your life, but don’t just trust the tests or the guru. Be your own guru. Feel your body, respond to it, keep what is good, and discard what is bad. It’s that simple.

By Cody Burkhart



Five percent. Doesn’t sound like much at first glance


Today we are going to get heady… in more ways than one. Might as well kick off the fun with a little nerdy dad-joke: my personal specialty.

What did my post row-interval pissed-off brain say to my nociceptor?

“You’re a real pain.”

Over the past week you have been digging into your test results, possibly collecting a few more data points to increase the quality of your experiment. You also probably got a few brief moments to gloss over some of the research topics I assigned as “speed dating” homework. We bought the yarn, studied the pattern, now let’s make us a quilt.

To begin fine tuning the analysis section I will refer back to my deltas that I posted last week:


The green column of distance variation pre and post the training mask interval testing was identified as our dominant measure. The intent in picking this measure goes back to the original question that put us on this path:

“If I strengthen the contractile function of the diaphragm, do I become super human or should we just let sleeping babes lie?”

I averaged a 348.5 meters per minute row interval over the four efforts on my baseline test. My resulting increase in row performance per interval (reminder: this is not considering any of my real-time data, but only compares where I started to where I finished in my re-test) was 17.75m. To solve for each of these all I did was add all my distances up for my baseline and divided by four, similarly I summed all my interval (green column) deltas from my post testing and divided by four. If I take the change I saw (17.75m), divide it by where I started (348.5m), and multiply by 100%… I will be solving for the percentage increase/decrease seen over the course of my experiment; in this case I saw approximately a 5% increase in my performance. There is nothing fancy about the math. There are tons of other statistical formulas we could run, but we are not trying to solve for pi to 100 decimal places here… we are trying to get a general grasp of what happened to our system (our bodies) by applying a new breathing tactic.

Five percent. Doesn’t sound like much at first glance. If I told you that you would get 5% off your next purchase you may not be moved to find this a considerable benefit on, say, your morning Starbucks. True, there are some of you that will run the numbers like me and see long term potential and become ecstatic for the 5%, but typically this could be seen as noise. When we talk about performance though, this is an entirely different story. If Usain bolt ran his world record 100m time from Berlin in 2009 (9.58s) the same 5% faster we wouldn’t just have a sub 9.5s human, we would have a 9.1s 100m bullet of a human soul. The same half a second decrease in the 100m time took over 50 years between 1956 with Willie Williams’ 10.1 and 2009 when Bolt hit his miraculous 9.58. Now, we are going to get plenty deep into the world touched on by David Epstein in “the Sports Gene” as it references technology’s hand in the improvement of human performance, but for now focus on the simple fact that 5% increase took over 50 years. Five percent. Doesn’t sound like much at first glance.

If I am trying to answer my base question with this organic progression of one of the most revered performance measures on earth, the answer is, certainly, “YES, diaphragm breathing for the win.” If analysis was that easy, you wouldn’t probably be cruising through this blog right now. The honest truth, however, is that it really is that easy. What isn’t easy is understanding if the connections we need to draw for this change, or any change that you might be experiencing from this or any other training method, are directed to our applied modification. What I mean by this is: did the training mask use increase my performance or was it the repetitive act of this new task or possibly the mentality I had during my baseline when I didn’t know what to expect v. my re-test when I knew what kind of consistent output I could manage? Fact is… I know, without a doubt, that I went harder on my re-test. I did, in fact, know that I could consistently hold a sub 1:30 500m split and not die by the final round in too terrible of a fashion. I also was in significantly more discomfort at the end of my fourth interval during my re-test than in my baseline.

If I left it here… you would walk away with “I knew there was a catch.”

Yeah, but I’m not the one who leaves it there because you have to also ask yourself the question: but what about fatigue from so many similar intervals of the same high intensity as a precursor to the re-test. I will tell you that I ran my baseline when I was sufficiently recovered to ensure there were no latent CNS fatigue issues or residual muscular deficiencies to skew my start point. The actual application occurred on back-to-back days… I came into the re-test practiced and timed, yes, but I also came in, effectively, more beat up. This is how the analysis game goes. It’s a rabbit hole of “well, wait, what about this factor’s influence on that factor?” This is why the addition of supplementary data can be highly beneficial.

Let’s take a look back at our toolkit of data: I had a decrease of my HR during and after my intervals as well as a lower saturation of oxygen. Considering we are talking breathing, I would be inclined to draw the immediate reaction that if I am getting more oxygen into my system during recovery, then wouldn’t my oxygen saturation rate show an increase when compared to my previous baseline? And since it doesn’t, wouldn’t that mean I wasn’t more efficient with my breathing? This assumes one tricky component that we can’t see: the levels of our CO2. Given that our SAO2 is higher than 95%, we are assumed to have normal neuron functioning, cellular oxygen supply to the muscles, and proper pressure. Fast check of our data confirms that we are in the clear, and definitely not below the 90% threshold that defines hypoxemia. How do we, know, then, if we are managing our CO2 better in response to our seemingly indeterminate results in oxygen levels in our blood? This is where the research side comes up to bat.

If the body doesn’t have enough CO2, that’s right I said NOT enough, bad things start to happen. If we follow the response of the negative side effects of clearing the off-gas CO2 from the energy pathway reactions in our body, something might just run into our data to help us out. Enter: hyperventilation. Go ahead… try it, we all know how. What happens? Feel like someone took your breath away when you are done? That’s because the over-breathing you just completed pushed more CO2 out than O2 in. The response of the body to the low levels of CO2 is vasoconstriction of the blood vessels to the brain and tightening of the airways. From last time we learned what happens to heart rate during vasoconstriction: it increases. Boom. I found my connection. I will know that I am over-breathing by the application of my diaphragm techniques, and that my drop in SAO2 is related to poor recovering breathing application, if I see a direct increase in my HR when compared to my baseline (and concurrently when compared to my decrease in SAO2 each interval). But, not the case. Instead my HR decreases as oxygen levels decrease and, overall, I am performing the extra workload at a lower HR demand. Supplementary data to the rescue.

I am not experiencing a CO2 fault, a concerning O2 decrease, and my heart rate overall is decreasing. The connections are starting to pan out between application of diaphragmatic breathing and performance increase. However, those of you who have dug deeper may blow the whistle here and throw out the “bull shit” flag for me using CO2 as an indicative measure to sew my story together, given the output time of my interval. By this I am referencing that efforts under 2min, but over :15-:30 access the fast glycolysis pathway of the Anaerobic system. This is that powerhouse system that uses a molecule of glucose to make a pair of ATP, some energy, and our friend lactic acid. Don’t hate on lactic acid, it’s just misunderstood… it’s actually the hydrogen ions (H+) that are reducing the affectivity of our muscles. Furthermore the accumulation of these ions in the blood slow down metabolism due to enzyme activity reduction. Slower metabolism = lower HR need. If I look at my results under this lens, I could say that I just had more glucose ready to get busy on my re-test day and that, no matter how I breathed, the results were going to improve because no oxygen was required for the pathway (i.e. Anaerobic = no oxygen).

Put down the pasta bowl you just whipped up in prideful celebration of proving carbs rule dominion over diaphragms. A brilliant scientist, Dr. Andy Galpin (while on our podcast), said it best:

“the metabolic pathways are much more like a paint brush of many colors, rather than an on and off function” (roughly translated)

I know for a fact that my heart rate stayed over 99 beats a minute throughout. This means, according to science, I stayed in tachycardia. Suddenly my fast glycolysis system was not being recovered, but I was sustaining a high stress to my system during a short recovery. Care to guess what efforts of over 2min but under 20min (my 18min test was no accident… it was informed preparation) fall under in the metabolic game of thrones? Slow glycolysis, an Aerobic function aka with oxygen. In slow glycolysis, lactic acid isn’t the waste product of the cycle, CO2 and water are via a combustion reaction. C02 levels rise, oxygen is used up, heart rate is down…. Hmmmm, could it possibly be that my breathing is keeping my slow glycolysis pathway active because of the sufficient levels of oxygen entering my body due to proper breathing dynamics? Consider this a bit… if your body knows it can’t get enough oxygen, do you think it’s going to lean on a highly oxygen driven energy system? And if my body knows it’s going to get more oxygen during the actual effort to run slow glycolysis in the background, then it can naturally, and confidently, secure the fast glycolysis pathway to perform at top output because it doesn’t have to continue running the non-renewable energy resource of local glucose in the muscles to recover. My body is becoming metabolically more adaptive. I can run the lactic acid levels and hydrogen ion levels up higher each interval because my proper gas exchange is going to run the recovery. Success is served.

Not every test will have these results. Not every test will succeed. You may have seen completely different responses to the stimulus than I did, but that doesn’t constitute a failure. If you are keto and you popped… perhaps you need to look at your protein and fat intakes more closely because your gluconeogenesis (producing glucose from non-carb substances) is not performing sufficiently. Perhaps you only saw increased performance, but at a cost of a higher heart rate. This is where inspection of your anaerobic threshold should be considered. You may have a low HR split to transition into fast glycolysis and need to recover longer from the heart rate spike of the workload.

Don’t become overwhelmed. One bite at a time is the best way to eat this elephant. The first bite was how to organize the data, the second bite was how to read it, the third was how to connect it… and, next, you need to apply it. Stay tuned, ladies and gents… this ride is only just beginning.