4 Ways to Build Resilience

Our modern world has become easy. We live in climate controlled houses, get in our climate controlled cars, and climate controlled offices and gyms. Over time, this makes us fragile. Ever notice that kids seem to be immune to swimming in cold water yet you get sick every time you travel? We have “endpoints” that our bodies get used to and if we don’t expose our bodies to difficult things, those endpoints narrow and then when we have to do something difficult, the body will let you know that it’s too much. Maybe you get sick, or maybe you develop pain. Whatever system in your body is most vulnerable, it shows up like a canary in a coal mine. 

Our bodies strive for homeostasis, or balance. We have 4 main homeostatic regulators; pH, CO2/O2, blood glucose, and temperature. The good news is that through systematic and progressive training, we can train our endpoints. This will make us antifragile, or resilient.

Here is an example: 

What is interesting is that if you improve the endpoints in one of these categories, it confers benefit in the other categories. Cold water immersion can improve your blood glucose control for example. Here are some tips to improve resiliency:

1. pH

This refers to your body's acidity/alkalinity in the bloodstream. It’s a 14 point scale, 0 is acidic and 14 is alkalinic. Our body rests at 7.4 and can typically swing between 7.35 and 7.45. You may have heard of the alkaline diet. Turns out it’s hard to have a large effect on pH through diet. The best way to affect pH is through breathwork. When you inhale, O2 goes up and it makes you more alkaline. As CO2 builds up in your bloodstream, it makes you more acidic. You can take advantage of this by doing things like breath holds while walking or Wim Hof breathing. 

Also, when you exercise, the muscles demand oxygen, that’s why you breathe heavier. The muscles also need fuel. Now, the body can use either fats or glucose for energy. Fats are more energy dense, but harder to break down whereas glucose is the opposite. So the harder you are working, the more glucose you are using. Glucose breaks down to lactate, which is the real fuel source, and hydrogen ions, which is acid. That is the burn you feel when you work out, literally acid. The more you can tolerate, the more you can exercise and the more resilient you become.

2. CO2/O2

Again, this comes down to breathwork. When CO2 builds up, there are sensors in our bodies that tell us to breathe to clear the CO2. CO2 has classically been described as a waste product, but that’s not accurate. The more it builds up, the more it scrubs oxygen off of the hemoglobin and delivers it to the muscle tissue. This is called the Bohr effect. So once again, the more CO2 we can tolerate, the harder we can work. 

3. Blood Glucose

This is tightly regulated in the body as high levels of glucose in the blood can be very damaging. In a healthy individual, there is on average about a teaspoon of glucose in the blood. When glucose is high in the blood, insulin is secreted to deliver the glucose to the muscles and the liver in the form of glycogen. As blood glucose decreases, glucagon is released to do just the opposite. 

With our traditional standard American diet, we eat way too much processed sugars and this leads to insulin resistance and type 2 diabetes. If you eat an excessively high carb diet (and we mean glucose, not just bread/pasta), your system gets adapted to burning glucose for exercise and burning fats become downregulated. If you get “hangry”, this is a sign that you have become metabolically inflexible and your ability to burn fats has decreased. You can improve this by running the “backup generator”. In other words, condition your body to burn fats from time to time. This can be done by exercising in a fasted state. Or you could consider a low carb/paleo diet. We don’t think there is one “right diet” for everyone. We advocate that you experiment and find the diet that works best, but it’s a good idea to sometimes focus on using fats for fuel to improve your metabolic flexibility as a strategy to become more resilient. 

4. Temperature

As stated earlier in the article, most of us live in a climate controlled environment. By intentionally seeking out cold and hot environments in a systematic way, we can improve the window of temperature swing that our body will tolerate before breaking down or getting sick. For starters, you can take a cold shower. Or exercise outside if you are in a warm or cold climate. You can use saunas and do cold water immersion. Cold plunges are all the rage now and for good reason. There are tons of benefits, but this is one of the big ones. We know that it upregulates the immune system, helps convert white fat into brown fat (which is more metabolically active), improves blood glucose, and reduces stress. Many people with hypothyroidism have poor cold tolerance. There is now emerging evidence that this is a 2 way street; if you improve cold tolerance, you may be able to improve thyroid function. Regardless, temperature is yet another homeostatic regulator that can be modified through graded exposure to make you more resilient. 

Building your resiliency is also called “physiologic flexibility”. This is a term coined by Dr. Mike T. Nelson and we are big believers in this approach. If you are interested in learning more and getting guidance on how to improve your physiologic flexibility in a systematic way, we’ve built a program for you. Click on the link below to learn more.

Is There a Connection Between Thyroid Function and Cold Exposure?

It is well known that those with hypothyroidism have poor tolerance to cold weather. The thyroid is heavily involved in metabolism and acts as a sort of thermostat for the body. When it becomes dysfunctional, it gets worse at regulating temperature and does not handle cold weather as well. Common advice is to avoid the cold. Is it possible that cold exposure is exactly what we should be doing? If we progressively improve the body’s tolerance to cold, can we influence the thyroid?

Homeostasis is the body’s desire to maintain balance, and we have many regulators of the body such as pH level, O2/CO2 levels, and blood-glucose. These regulators are tightly regulated; for example, if you are exercising vigorously, you are rapidly depleting oxygen because your muscle is using it. To increase oxygen levels, you’ll start breathing through your mouth. As you exercise more, the demand for oxygen decreases because you are becoming a more efficient machine so you will be able to exercise longer and harder before needing to breathe through your mouth. This is called “adaptive homeostasis” and is the basis behind any kind of performance training. This, by the way, is information from a course I just took from Dr. Mike T. Nelson called “Physiologic Flexibility” (which I highly recommend).

What is interesting is that these homeostatic regulators are two way streets, meaning if you work on your ability to be in a hypoxic state (low oxygen), it can increase your exercise tolerance and vice versa.

Temperature is also a homeostatic regulator. So if homeostatic regulators are two way streets, and those with hypothyroidism poorly tolerate the cold, can we influence the thyroid by cold water immersion? There is some preliminary research that suggests this might be true.

In 2014, a study was conducted in New Zealand (Mustafa & Elgazzar) where they took white rabbits and kept them in a cold room (39.2 degrees Fahrenheit) for 7 weeks. Compared to a control group, the cold group had more free T3 and T4 (thyroid hormones), had more conversion of T4 to T3, and increased uptake of the thyroid; all indicators of improved thyroid function. 

Of course these are rabbits, and their physiology is not identical to ours. It’s hard to get human volunteers to sit in a cold room for 7 weeks, nor would any ethics board approve it. However, with the popularity of cold water immersion on the rise, this could be an easily conducted study in humans. 

How can we explain this? Two words, Brown Fat. Well actually it’s 3, Brown Adipose Tissue, which I’ll abbreviate to BAT. There is white fat, or WAT, and BAT. The difference is that BAT has mitochondria in it which are metabolically active and are what make the change from a white color to brown color. Babies are born with a lot of BAT and it’s why babies don't shiver. The mitochondria are able to regulate temperature. Our body has a few ways to warm up, through mitochondria and through shivering. The fact that babies have BAT is the reason they don’t shiver. It was long thought that as we age, we convert BAT to WAT and then the need to shiver increases. However, it may be due to a modern lifestyle and less exposure to the elements. 

There are tons of studies that show that cold exposure can convert WAT to BAT such as this one. And this study shows that higher levels of BAT are associated with higher levels of thyroid hormone. 

I think it is fascinating that something as simple as cold exposure may have an influence on our endocrine system, and this could have huge implications. Hopefully, there will be more evidence coming out on this topic, meanwhile, I’ll be jumping in my ice bath. 

References:

Broeders EPM, Vijgen GHEJ, Havekes B, Bouvy ND, Mottaghy FM, et al. (2018) Correction: Thyroid Hormone Activates Brown Adipose Tissue and Increases Non-Shivering Thermogenesis—A Cohort Study in a Group of Thyroid Carcinoma Patients. PLOS ONE 13(12): e0209225. https://doi.org/10.1371/journal.pone.0209225

Mustafa S, Elgazzar A. Influence of chronic exposure to cold environment on thyroid gland function in rabbits. Horm Metab Res. 2014 Jul;46(8):546-9. doi: 10.1055/s-0033-1363284. Epub 2014 Jan 20. PMID: 24446160.

Peres Valgas da Silva C, Hernández-Saavedra D, White JD, Stanford KI. Cold and Exercise: Therapeutic Tools to Activate Brown Adipose Tissue and Combat Obesity. Biology (Basel). 2019 Feb 12;8(1):9. doi: 10.3390/biology8010009. PMID: 30759802; PMCID: PMC6466122.

How to Use Breathing to Improve Exercise Endurance

If you don’t have any access to cardio equipment, or just find cardio machines boring, there are other techniques to improve endurance. When I say endurance, I’m talking about the tolerance to that ‘burning’ feeling your muscles get when exercising. 

This one might get a little technical, so hang in there. We have to understand some basic biochemistry to get through this. 

You may have heard that the ‘burn’ while exercising is lactic acid. That’s not technically true. Your body can use both lipids and carbohydrates as fuel. The body prefers to use lipids for energy because they produce more energy (ATP). The trade off is that it’s a slower process for the body. Carbohydrates are more readily available, yet produce less energy. So, when you are just sitting around, or doing low intensity exercise, you’re primarily using lipids. As intensity increases, the body will start to use more carbohydrates out of pure demand. 

Carbohydrates are stored in the muscle in the form of glycogen. Glycogen is broken down into lactic acid, which in turn is immediately dissociated into lactate and hydrogen ions. Lactate is a great fuel source, but its by-product, hydrogen ions (H+) are literally acid. This is what causes the burning sensation. 

As you exercise, this acid starts to build up. The body has a few mechanisms to buffer this. In the muscle cell itself, carnosine soaks up the hydrogen ions. In the bloodstream, bicarbonate does the same thing. The body is great at adaptation, so if you incrementally expose the body to this mild stress, these buffering mechanisms become more efficient. Just like resistance training, progressive load has the long term effect of making you stronger. 

It turns out that you can induce an acidic environment simply through breathing. The more oxygen in the bloodstream, the more alkalinic, the more CO2, the more acidic. So you can leverage this by limiting the volume of breathing because exhaling through your mouth off gasses CO2. 

This is where nasal breathing comes into play. Nasal breathing has many benefits including the stimulation of nitric oxide production which dilates the blood vessels (good for cardiovascular system). But, because you can’t exhale as strongly through your nose versus your mouth, it will increase CO2 build up, causing an acidic environment. If done during a low intensity exercise, such as walking, it is enough of a stressor to stimulate adaptation to the system. In other words, a mildly acidic environment during exercise will improve your body’s ability to buffer hydrogen ions. If you do this consistently, your body will be able to handle acidic environments during workouts better, leading to greater output. This is the idea of physiologic flexibility. 

Some call this CO2 tolerance, or the CO2 advantage. I wrote another blog that describes a test you can do to see how well you tolerate the buildup of CO2, you can read it here. 

So all you have to do is find a light exercise that you can do while only nasal breathing. For most, it’s walking. Perhaps you start with short bouts and increase over time. Make it something that easy so you don’t quit doing it, because it can be uncomfortable. If you are strongly feeling the urge to breathe through your mouth, that’s ok, go ahead and do that. Now you know your threshold. Progress over time and notice how it translates to other forms of exercise.