As we gain deeper insight into the metabolic pathways that turn food and air into the electrochemical miracle of the human body, we also learn ways to maximize our physiological potential.
That insight becomes particularly relevant amid a global pandemic and the widespread prevalence of chronic disease. The torrent of stress we encounter each day can trigger a low-grade fight-or-flight response via the sympathetic nervous system and leave us increasingly fragile. Fortunately, we can also find ways to use certain kinds of stress to strengthen ourselves.
Antifragility is a term coined by economist Nassim Taleb to describe a state that is the opposite of fragility. Antifragility describes how stress makes you stronger rather than breaking you down. Siim Land’s latest book, “Stronger by Stress: Adapt to Beneficial Stressors to Improve Your Health and Strengthen the Body,” which came out in July 2020, reviews the really important concepts of hormesis and antifragility.
Hormesis describes how low doses of a stressor or toxin can have beneficial results even though higher doses would hurt us. An example would be how jumping around can stress the bones and make them stronger, even though falling from a height can break them. This phenomenon is at the core of antifragility.
“[Antifragility] isn’t precisely the same thing as robustness or resilience,” Land says. “Something that is robust is something like a piece of stone or a metal. You can heat it, you can drop it on the ground. It’s not going to break, but it’s going to stay the same, it’s not going to change, whereas something that is antifragile is going to gain from the stress.
“The book itself was meant to create more resilient people in the face of these unavoidable challenges of life, because you can’t really avoid them. You can’t create this bubble society where everything is perfect. We all come across different kinds of stressors all the time.”
Land warns that being unfit or lacking key nutrients, such as vitamin D, which is critical to fighting off COVID, will leave you prone to stress. In that state, even small stressors like traffic are going to seem significant. The result: an overactive sympathetic nervous system.
“On the other hand, if your body has been exposed to the right amount of stress at the right time, then it has also built up this higher level of stress adaptation and resilience. So, the small stressors are becoming literally meaningless. You have a bigger capacity to face even the larger stressors.”
Stronger by Stress
Beyond maintaining enough key nutrients such as vitamin D, achieving metabolic flexibility can also improve your resilience against stress. Intermittent fasting, or time-restricted eating, is one of the best ways to achieve metabolic flexibility. It can also help you stay insulin sensitive amid a rising tide of diabetes.
Land points to a 2019 study published in the New England Journal of Medicine found that intermittent fasting has life extension benefits and turns on certain key defensive mechanisms inside a body that make it more antifragile while providing additional health benefits.
Land says intermittent fasting also has other benefits, “like increased glutathione, increased NRF2, sirtuins and NAD and many other longevity-boosting and immune-strengthening pathways that get activated when you’re fasting that don’t necessarily get activated when you are restricting calories.”
One of the key benefits of intermittent fasting is that it can trigger autophagy. Autophagy is the recycling of damaged and old cells so their proteins can be used to create new amino acids to make new tissue. Effective autophagy is essential for the body to keep itself in good repair.
Time-Restricted Eating for Muscle Building
A persistent question surrounding intermittent fasting is what the best strategy is. Should you eat just once a day, or can you get away with two or more meals as long as you eat it all within a certain time window? And, if so, how long can that window be?
The answer to that question depends heavily on what your goal is and a substance called mTOR (mammalian target of rapamycin). MTOR is best described as the master controller of protein synthesis. When you have a lot of mTOR, it promotes growth in the body and can help you build muscle. When it is low, your body shifts to repair and maintenance and increases autophagy.
MTOR production is fueled by glucose, which we get from eating carbohydrates, and amino acids, which we get largely from protein. So when you eat more of these foods, you create more mTOR.
If your intention is to build muscle, having two meals a day within a six- to eight-hour window would make more sense. Having just one meal a day is likely better if you are seeking to lose weight, but might be challenging.
This is likely for the simple reason that you’re only going to build muscle when you activate mTOR, and to activate mTOR, you need to introduce protein and leucine or branched-chain amino acids, along with some healthy carbohydrates.
If you eat twice, six hours apart, you can activate mTOR twice a day, thus allowing you to get better muscle-building benefits.
“That’s why if someone has the goal of increasing their muscle mass, maintaining muscle mass or preventing sarcopenia [muscle wasting], then for them, it is much wiser to incorporate more frequent meals. For them, I would say that a 16-to-8 type of fasting where they eat twice a day is perfectly suitable, and is actually better than the one meal a day.
“It becomes increasingly more difficult to maintain muscle mass if you’re already predisposed to sarcopenia and you’re eating once a day, because there’s a threshold of how much mTOR you can stimulate per meal, and how much muscle protein synthesis you can create per meal as well. It doesn’t have to mean that you start eating six times a day. Increasing the eating window is generally a better idea.
“For most people, I would say that the 16-to-8 type of fasting, where they fast for 16 hours and eat within eight hours, is a really good balance between getting a daily stimulation in autophagy, while, at the same time, also stimulating enough mTOR and being able to build muscle.”
I found this advice personally helpful as I was pushing my eating window to four hours, but after Land related this commonsense strategy, I extended it to six to eight hours, which actually is easier on the kidneys. Also, as noted by Land, pushing your eating window to be excessively narrow can backfire and slow down your metabolism.
In the context of stress adaptation and antifragility, if your body becomes too accustomed to fasting because you’re eating only one meal a day all the time, then that can eventually slow your metabolism and lower thyroid functioning. This, in turn, makes you more prone to insulin resistance, which is exactly what you’re trying to avoid by eating just once a day.
Carbs Aren’t All Bad
While carbs have gotten a bad rap, they are still an important part of your diet. In fact, when you’re seeking to stimulate mTOR, carbs may be just as important as protein, because insulin secretion is a powerful activator of mTOR. Insulin secretion is triggered by the glucose we get from carbs.
I believe carb cycling, which means eating more carbs on some days and less or none on others, can be highly beneficial in this respect. If you’re chronically low-carb, it will provide you with significant benefits initially, but long term, it can backfire. Land explains:
“Carbs can be useful for muscle growth, but they’re not a necessary part of it. You can stimulate mTOR and build muscle with protein only … but the insulin is still a very powerful anabolic hormone and it does help. It is possible to build muscle with a low carb or a ketogenic diet, but at the same time, carbs can be also useful.”
Ketogenic diets focus on eating few or no carbs so that your body switches from getting its energy from glucose to getting its energy from fat—including the fat stored on your waistline.
Being able to swap back and forth from relying on blood sugar for energy to relying on fat for energy is an important aspect of metabolic flexibility. But simply relying on fat for energy isn’t the cure-all some people hope it is.
“Chronic ketosis can eventually lead to insulin resistance or some mild forms of it,” Land notes.
“I believe a more flexible approach is better in the long-term because you’re able to still use both. You’re still able to become a fat burner while, at the same time, you don’t become insulin resistant toward carbs either, and you can incorporate both.
“In practice that would mean that people can do some form of cyclical keto diet, where they eat keto on some days but also incorporate some days where they eat more carbs to kick themselves out of ketosis, as well as break this mild insulin resistance that may develop. I myself like to eat keto on days where I’m not working out.
“So, on my rest days where I don’t have a lot of physical activity, then it’s perfect to stay in ketosis and eat low carb because my body isn’t burning that many carbs for fuel either, whereas on days where I do high-intensity training or some resistance training, or on days when I want to really stimulate mTOR, and on those days, I’ll just have more carbs because the body uses carbs and glycogen during a workout.
“If you eat carbs after a workout, then the body is already primed to use those carbs more efficiently instead of storing them as fat or instead of developing diabetes from it. So, it’s a perfect time to strategize or time your carbohydrate intake around your exercise.
“Your body is the most insulin sensitive after a workout because the muscle contractions activate the glucose transporter GLUT4. Then you don’t even need insulin to shuttle carbs into muscle cells either. So that’s why having some carbs around a workout itself won’t necessarily be harmful as long as you are still metabolically flexible and you have metabolic health.”
Land’s explanation above caused me to change my own carb cycling to a more optimal schedule. While nothing is set in stone and listening to your body is important, if you are not insulin resistant, I believe cycling in carbs once or twice a week and remaining low-carb, below 50 grams per day, the rest of the week is a good strategy, as nutritional ketosis has so many profound metabolic benefits.
That said, if you’re already insulin-resistant, as 90 percent of the population is, or diabetic, then adding carbs will be counterproductive, so it’s important to assess your individual situation. If your metabolic flexibility is already good, then being on a restrictive low-carb diet isn’t really necessary anymore.
The Benefits of Heat-Shock, Cold-Shock Proteins
Beyond intermittent fasting, there are also other ways you can introduce minor stressors into your life to help you achieve antifragility.
“Stronger by Stress” also delves into the science of heat-shock proteins and cold-shock proteins, activated by exposure to heat and cold respectively.
Heat-shock proteins repair misfolded proteins and RNA, increase glutathione, and promote autophagy, among other things.
Cold-shock proteins also activate antioxidant defense mechanisms, and lower inflammation and oxidative stress.
Born and raised in Estonia, Land is familiar with the cold, and embraces cold exposure for its physical conditioning and mental toughness benefits.
“If you are habitually engaging in cold exposure throughout the entire year, then the winter itself becomes a piece of cake. It becomes less stressful on yourself and it becomes less damaging. You’re able to adapt to it faster than normal people.
“If you’re constantly using central heating or you’re using the heating in your car and you’re never really exposed to the cold for any longer than a few minutes, then you’re missing out on the benefits of the cold shock proteins. You’re also making your body more vulnerable and more fragile,” he says.
“The mental aspect is also really great. I used to take a cold shower every morning, and it really helped me develop more self-discipline and self-control.”
“The rationale for me was that if I’m able to start the day with a cold shower, then anything else for the rest of the day is going to be that much easier because I already climbed over this initial challenge.”
Muscle Building Is Essential to Avoid Sarcopenia
One of the best stressors you can introduce or increase to make you stronger is exercise. In the interview, Land reviews some of his recommendations for high-intensity resistance training, such as doing multiple sets, split training, and other strategies that are also covered in his book. As noted by Land, maintaining muscle and keeping physically active are probably two of the best things you can do to extend both your life span and health span.
Age-related muscle loss, called sarcopenia, is a significant threat to health that virtually no one can escape. Use it or lose it applies here, and muscle is far easier to lose than gain. Especially as you age, muscle is lost much faster when you are inactive.
For this reason, I strongly recommend strength training for all ages, especially the elderly. The good news is you can effectively build muscle without risking injury from heavy loads by using blood flow restriction (BFR) training. In Japan, where the technique was developed, it’s known as KAATSU.
BRF is also a minor stressor. It involves exercising your muscles while partially restricting arterial inflow and fully restricting venous outflow in either both proximal arms or legs.
Venous flow restriction is achieved by using thin elastic bands on the extremity being exercised. By restricting the venous blood flow, you create a relatively hypoxic (low oxygen) environment in the exercising muscle, which, in turn, triggers a number of physiological benefits, including the production of hormones such as growth hormone and IGF-1, commonly referred to as “the fitness hormones.”
It also increases vascular endothelial growth factor (VEGF), which acts as “fertilizer” for growing more blood vessels and improving their lining (endothelium).
I believe BFR is one of the best strategies available to address the epidemic of sarcopenia, and for most people who aren’t competitive athletes, it may be the only form of resistance training they need. Land, like me, is a big fan of the KAATSU system and uses it every day.
“If I’m not doing an actual workout with them, then I’ll just use the KAATSU cycle, the on and off pressures. So even if I’m not doing an actual exercise with them, then I’ll still do the cycle to pump more blood into the muscle and accelerate recovery,” he says.
“On other days, I’ll use [the bands while doing] biceps curls and pushups. With the legs, I’ll do squats and lunges, or just regular walking. I really enjoy them and I find that they accelerate recovery. Even if it’s not for the exercise performance, I think the cardiovascular effects are still worthwhile.”
It’s important to realize that sarcopenia isn’t just cosmetic, and it’s not just about frailty. Your muscle tissue, which makes up about half of your body’s tissues, is a metabolic organ, an endocrine organ. Your muscle tissue makes cytokines and myokines, and is a sink for glucose.
Insulin resistance and Type 2 diabetes accelerate sarcopenia, and research shows glucose fluctuations are independently associated with this condition. As noted in one 2019 study published in the Journal of Clinical Medicine, “glucose fluctuations were significantly associated with a low muscle mass, low grip strength, and slow walking speed.”
The effectiveness of BFR for the prevention and reversal of muscle wasting is directly addressed in an April 2019 study in the Journal of Cachexia, Sarcopenia and Muscle:
“Muscle wasting leads to significant decrements in muscle strength, cardiorespiratory, and functional capacity, which increase mortality rates. As a consequence, different interventions have been tested to minimize muscle wasting.”
“In this regard, blood flow restriction (BFR) has been used as a novel therapeutic approach to mitigate the burden associated with muscle waste conditions.”
“Evidence has shown that BFR per se can counteract muscle wasting during immobilization or bed rest. Moreover, BFR has also been applied while performing low-intensity resistance and endurance exercises and produced increases in muscle strength and mass.”
“Endurance training with BFR has also been proved to increase cardiorespiratory fitness. Thus, frail patients can benefit from exercising with BFR due to the lower cardiovascular and joint stress compared with traditional high-intensity exercises.”
“Therefore, low-intensity resistance and endurance training combined with BFR may be considered as a novel and attractive intervention to counteract muscle wasting and to decrease the burden associated with this condition.”
Life is full of challenges and difficulties. The good news, and a key lesson we can learn from Land, is that we can better prepare ourselves for these inevitable hardships by introducing minor stressors.
“It’s important to engage in these small stressors that have a hormetic effect on a regular basis because they’re not permanent. You’re going to lose them if you don’t use them. So, if you don’t use the sauna, then you’re going to lose your ability to tolerate heat. The same applies to exercise, to fasting,” he says.
“Those things should be a part of your regular lifestyle. They are really beneficial for your overall longevity as well as just resilience against stress. So, I personally feel that doing intermittent fasting, cold showers, heat exposure—all those things have helped me tolerate stress in other areas of life much better.
“I’m able to tolerate stress from work, I’m able to tolerate stress from other people so I don’t get triggered or I don’t get angry at other people. I’m not stressed out from those things because my stress resiliency is much higher than it is in the average person.”