The Wealth of Selection15 minute read

Steven Kornweiss, MD biochemistry, endocrinology, exercise, nutrition Leave a Comment

It was Mulligan and Akston who served dinner, with Quentin Daniels to help them. They served it on small silver trays, to be placed on the arms of the chairs—and they all sat about the room, with the fire of the sky fading in the windows and sparkles of electric light glittering in the wine glasses. There was an air of luxury about the room, but it was the luxury of expert simplicity; she noted the costly furniture, carefully chosen for comfort, bought somewhere at a time when luxury had still been an art. There were no superfluous objects, but she noticed a small canvas by a great master of the Renaissance worth a fortune, she noticed an Oriental rug of a texture and color that belonged under glass in a museum. This was Mulligan’s concept of wealth, she thought—the wealth of selection, not of accumulation.

— Ayn Rand, Atlas Shrugged

Summary First

In the industrialized world, calorically dense foods are cheap, plentiful, and palatable. Thus, many struggle to limit their caloric intake. However, some people struggle with the opposite problem, excessive restriction. It’s now recognized that competitive female athletes are prone to be over-restrictive as a result of internal and external influences. Restricting calories below what’s needed to maintain physiologic functions can harm performance, hamper recovery, and lead to serious medical conditions such as amenorrhea and osteoporosis.

Thanks to sports-medicine doctors, researchers, and outspoken athletes like Mary Cain, Sarah Sigmundsdottir, and Emma Abrahamson, the phenomenon of energy-deficiency in female athletes is now appreciated by more coaches, trainers, and athletes. Despite this, many female athletes still make the mistake of under-nutrition and under-recovery. Few know that this is also a problem that afflicts male athletes, military personnel, and even people who exercise for recreational or aesthetic purposes. Performance, short-term, and long-term health all depend on proper energy balance. Too much energy is bad and so is too little. This article explores the problem of “too little,” how to recognize it, and how to avoid it.

The Fundamental Problem

The quest to be selective, to avoid the wealth of accumulation, is the fundamental problem that most of us face with regard to nutrition.

Food is available everywhere in almost unlimited quantities at minimal cost. What’s worse, the most ubiquitous and convenient food is often the least expensive on a dollar per calorie basis. Consider, for example, that a quarter-pounder with cheese, small fries, and a small soda surpasses 1000 calories for five or six dollars for a ratio of 200:1 calories per dollar. Compare this to a relatively energy-dense fruit like an avocado. A single large Hass avocado at Whole Foods costs $2.99 and contains roughly 230 calories for a ratio of only 77:1 calories per dollar. Spinach is even more expensive per calorie. A 5 oz bag of spinach costs $2.49 and contains only 33 calories for a ratio of 13:1 calories per dollar.

Food Calories per dollar
1/4 lb Cheeseburger, fries, soda 200
Avocado 77
Spinach 13

Consider now that the food that supplies the greatest amount of energy at the lowest cost is also more convenient to find and eat, and it’s more rewarding, and therefore habit forming. It’s not surprising that with regard to nutrition, most American’s suffer from a wealth of accumulation when instead, we should be enjoying a wealth of selection.

When Selection Becomes Restriction

It’s well-understood by those who care about their vitality, fitness, appearance, and longevity that if we want to realize our true potential, we must be selective when it comes to nutrition. But, selectivity can also go too far. In some cases, in the pursuit of health and wellbeing, selection can become restriction.

This problem is particularly common among competitive athletes, military trainees and operators, models, and individuals who train and eat with the purpose of improving their performance.

Mary Cain

Mary Cain was the fastest junior in US middle-distance running. In 2013, at the age of 17, she set records in the 3000, 1500, and the 800 meter. It was a foregone conclusion that she would become an Olympic champion. In 2016, she was recruited to join the elite Nike Oregon Project team which promised to develop her and other top junior athletes into Olympic champions. Initially, she continued to perform at a world-class level. But, shortly after joining, now disgraced head coach Alberto Salazar pressured Mary to lose weight.

Mary restricted her nutrition. Her menstrual periods ceased entirely. She suffered multiple stress fractures due to declining bone density. Her running performance suffered. Her mental health deteriorated, and she ultimately had to leave competitive running. In 2019, Mary spoke out about the psychological abuses she suffered while part of the Nike Oregon Project team. She later filed a lawsuit which resulted in investigations and the dissolution of the project. Mary has since been outspoken about the mistreatment of women in sports and about her experience and recovery from amenorrhea.

Mary’s coaches thought weight loss would enable her to run faster by requiring her to move less weight with each step. This concept is ubiquitous in sports for which speed matters, especially over long-distances. In Formula 1 racing, engineers seek to strip the car of all but the bare necessities in order to have the highest power to weight ratio. They look for the most rigid and light-weight materials with which to build the car. In cycling, engineers perform the same task when designing bicycles. Cyclists try to become as lean as possible, and middle and long-distance runners do the same. Carrying an extra 5 or 10 pounds up a mountain or around a track for hours is energetically costly and thus can be the difference between winning and losing. But, there are healthful ways of losing weight, and others which are detrimental. Removing the fuel tank from a race-car will make it lighter but not faster. Amputating a runner’s leg will make her lighter but not faster. Restricting nutrition and losing too much weight can strip a person of the fuel and parts she needs to perform and thrive.

These seemingly ridiculous examples are similar in essence to what happened to Mary Cain. But, why is it that Mary stopped having a menstrual period and suffered a physical and mental breakdown from caloric restriction?

To answer this, we need to ask the most fundamental question about food. Why do we need it at all?

Why Do We Need to Eat?

Our food provides molecules that can be divided into two broad categories:

  1. Structural molecules like amino acids, minerals, and co-factors, which provide the raw material for our frame (bones, muscles, and connective tissue), and for the machinery that allows us to grow and move (genetic material, proteins, and enzymes).
  2. Energy molecules (e.g. sugars, carbohydrates, and fats) that can be burned to produce energy.

Energy is required for at least these six basic functions:

  1. Growth
  2. Movement / Locomotion
  3. Cognition
  4. Thermoregulation
  5. Reproduction
  6. Immunity

When We Consume Too Little

Of these six physiologic functions, growth and fertility are the least essential for immediate survival. In the case that we are anticipating energy deficiency, or we are outright deficient, the hypothalamus and pituitary gland can shut down growth and reproduction via the endocrine system. Under periods of restricted sleep and nutrition, and under intense physical or psychological stress, all six of these are affected. We can all recall a time when intense periods of stress seemed to coincide with feeling too hot or too cold, having decreased libido, physical sluggishness, mental fatigue, and being more susceptible to illness.

For women, consuming too little energy to match the demands of one’s physiologic needs can cause amenorrhea, the loss of one’s menstrual period. For many years, the athletic world in particular, which has been dominated by male trainers, coaches, and doctors, considered it normal for competitive female athletes to lose their menstrual periods. It’s now recognized that this is an abnormal physiologic state which indicates that an individual is not consuming enough energy in order to meet the demands of both training and reproduction. The medical term for this condition is Functional Hypothalamic Amenorrhea (FHA). This condition is related to, but not identical to “relative energy deficiency in sport (RED-S)” and “the female athlete triad.”

Functional Hypothalamic Amenorrhea

Individuals with FHA are more likely to have difficulty recovering from training than their counterparts with intact menstrual cycles. They’re more likely to sustain injuries and to have difficulty healing. They’re more prone to osteoporosis even at a young age, and may be more prone to cardiovascular disease and a multitude of physiologic and psychological ailments. Among female athletes, this syndrome is common. One reference estimates that as many as 79% of female athletes (depending on the sport and level of competitiveness) may have FHA.

It’s hard to know exactly how many young women suffer from this problem, as it’s historically been normalized within female athletic circles and within much of the medical community. However, several prominent female athletes have spoken publicly about their struggle with amenorrhea.

In addition to Mary Cain, Sarah Sigmundsdottir, a well known female CrossFit athlete has publicly discussed her amenorrhea.

When she first began competing in the games, she lost her period for two years. She consulted a physician who told her that losing your period “is just normal for athletes.” Sigmundsdottir didn’t accept this answer and opted instead to adjust her nutrition and training volume to maintain her health and performance.

Collegiate runner Emma Abrahamson didn’t have her first menstrual period until age 22. In 2019, she shared her story in this Youtube video and in this article in Women’s Running.

One of my former clients, a collegiate athlete turned recreational crossfitter, endured more than three years of amenorrhea. Based on the estimates in the literature, the few public reports of prominent female athletes, experience in my practice, and in discussion with other healthcare professionals, this is an enormously common problem.

Men Too

This isn’t a problem only for women. I myself have suffered from the male correlate of this condition. In men, this problem can be even more insidious. Women often become aware of the extent of the problem only after a prolonged period of amenorrhea. In men, the early signs might only be stagnation of performance, exercise intolerance, excessive fatigue, irritability, decreased desire to train, decreased libido, and non-healing injuries. There are no in-your-face signs in men the way there are in women. Athletes are prone to fatigue and injury even when healthy, and prefer not to show weakness, so it’s easy for these signs to go unnoticed or willfully ignored.

My athletic capabilities are decidedly average. On my college cycling team, I could hardly keep up even on training rides. In races, I was dropped by the main group so quickly, it was impossible not to become demoralized. Nonetheless, I fancied myself a competitive cyclist. At the time, I was obsessed with professional cycling, and with Lance Armstrong in particular.

My Lance Armstrong Library

My understanding of cycling performance came from watching the Tour de France and reading books like “The Lance Armstrong Performance Program” by Chris Carmichael.

Carmichael’s book actually has pretty good advice for nutrition and weight loss. For instance, in the chapter titled “Eat for Health and Performance,” Carmichael writes the following:

“Lance followed established steps to safe weight loss. It all comes down to balancing intake against what gets burned up. Crash diets are aptly named and should be avoided. Severe food restriction (fasting or low-calorie diets) result in trimming lean body mass and water instead of fat. The best approach is for a slow but steady weight loss while converting fat to muscle for a trimmer body.”

He then goes on to describe a 9 week plan for losing 10 pounds. All of this sounds pretty good, except for the fact that Carmichael wasn’t actually Lance’s trainer at all. We now know he was little more than a figurehead (1:03:45).

Michele Ferrari was Lance’s real trainer. Ferrari is now notorious for having been one of the most sought after doctors who assisted professional cyclists with “performance enhancement” during the Armstrong era.

Ferrari was obsessed with doping, but also with power-to-weight ratio. It’s the most important metric in cycling, especially when it comes to winning grand tours like the Tour de France in which the winner must rapidly ascend thousands of feet through the French Alps and Pyrenees. According to this test by GCN, an extra 10 pounds of weight can cost a cyclist over a minute for every 20-30 minutes of climbing on a 7% gradient. This means a single pound might cost a cyclist 20 or 30 seconds on a single climb in the Tour de France. This can easily mean the difference between winning or losing the race. As such, professional cyclists in competition are particularly lean.

Photograph of Armstrong in the 2005 Tour de France

In his book, “The Secret Race,” ex-Armstrong teammate and world-class cyclist Tyler Hamilton tells us just how extreme Ferrari’s attitude was towards weight loss:

Eating meals with Ferrari was a nightmare. He’d eagle-eye each bite that went into your mouth; a cookie or piece of cake would bring a raise of the eyebrow, and a disappointed look. He even persuaded Lance to buy a scale so he could weigh his food. I never went that far, but with his guidance, I tried different strategies: I drank gallons of sparkling water, trying to fool my stomach into thinking it was full.

I spent more time thinking about how to lose weight than I ever spent thinking about doping: the question haunted every meal, every bite I took. Bjarne recommended his special technique: come home from a training ride, chug a big bottle of fizzy water, and take two or three sleeping pills. By the time you woke up, it would be dinner, or, if you were lucky, breakfast. I tried everything. I drank gallons of Diet Coke. I tried eating lots of raw food — diets of apples and celery. I sucked on butterscotch candies to calm my growling stomach. Every morsel I ate had to be burned off.

When I joined my university cycling team, I weighed 155 pounds. Many cyclists of my height weighed under 140 pounds. For a frame of reference, Chris Froome, winner of the Tour de France in 2013, 15, 16, and 17, is 6’1’’ to my 5’6’’ and he was a mere 150 lbs in competition.

The Times – “My sporting body, by Chris Froome”

To lose weight, I ate only when I felt hungry, and just enough until the hunger went away, and then I’d stop. I was in college, so I was eating crackers and cereal…not the most nutritionally complete diet. I made it down to my goal weight of 140 pounds. I was exhausted and freezing cold all the time. In fact, the only time I felt any good was when I was on the bike. With less weight to lug up the mountains, my climbing performance improved a little, but ultimately, I was still quite average.

In medical school, I took up CrossFit. At that time, the paleo diet was very much in vogue with CrossFitters. I consumed minimal carbohydrates and cut calories by 500 kcals/day while increasing my training frequency and volume significantly. To be clear, these were my own decisions and not prescribed by my gym, by CrossFit, or by any “paleo diet” authority. This was purely my responsibility. At first, my performance improved and I became lean and muscular. But, after a few months, I became exhausted and started to crave ice cream by the bucket. I made this sort of mistake a few more times before I finally figured out that it’s impossible to be healthy, to feel vigorous, and to perform well unless you’re consuming enough energy and training at a volume and intensity that allows you to recover and flourish physiologically.

A particularly well characterized example of how energy and sleep deprivation affects men comes from studies of Army Ranger School students.

According to a fascinating article in Outside Online, students in Army Ranger School carry 90-pound rucks up and down mountains outside of Columbus, Georgia for 61 days. They sleep two or three hours a night and eat two daily MREs for a total of roughly 2,500 daily kcal. This is only one half or one-third of their daily energy expenditure. In other words, the students simultaneously endure an enormous volume of training and a severe energy deficit. By the time they graduate, many lose at least 20 pounds, one pound roughly every three days.

In 2000, Friedl et al. published an incredible study of roughly 100 Army Ranger students as they underwent the training course. The students were split into two groups. Group one had a daily energy deficit of roughly 1,200 kcal whereas group two had a deficit of only 1,000 kcal. By week eight, both groups suffered significant weight loss and biochemical aberrations. The group with more restriction lost more weight, but even group two (the group with a smaller caloric deficit) had the following biochemical aberrations:

  • Average serum testosterone decreased to one-eighth its normal level
  • Leutinizing hormone (LH) decreased by 50%
  • Cortisol and sex hormone-binding globulin (SHBG) nearly doubled
  • Insulin-like growth factor (IGF-I) decreased by more than 50%.
Metric Start 4 wk 5 wk 8 wk +5 wk
Body weight, kg 73.9 ± 2.9 68.1 ± 2.3 73.9 ± 1.5 65.5 ± 2.3 76.3 ± 3.0
Fat weight, kg 9.5 ± 1.5 ND ND 5.3 ± 0.9 13.7 ± 1.2
Fat-free mass, kg 64.4 ± 1.6 ND ND 60.2 ± 1.9 65.5 ± 2.2
HDL cholesterol, mmol/l 1.3 ± 0.1 1.7 ± 0.1 1.9 ± 0.1 2.3 ± 0.2 1.2 ± 0.2
Cortisol, nmol/l 441 ± 22 417 ± 31 550 ± 50 706 ± 34 507 ± 51
IGF-I, μg/l 205 ± 16 101 ± 71 85 ± 21 88 ± 7 253 ± 11
3,5,3′-Triiodothyronine, nmol/l 1.84 ± 0.16 1.55 ± 0.11 1.96 ± 0.07 1.47 ± 0.08 2.46 ± 0.10
TSH, mU/l 2.4 ± 0.2 3.7 ± 0.5 3.0 ± 0.3 4.5 ± 0.5 2.7 ± 0.4
Thyroxine binding globulin, nmol/l 20.3 ± 1.0 22.9 ± 0.8 20.7 ± 1.1 24.0 ± 1.5 18.4 ± 0.9
Testosterone, nmol/l 16.3 ± 1.6 4.3 ± 0.5 14.6 ± 0.8 2.2 ± 0.9 19.3 ± 3.2
LH, U/l 8.0 ± 0.7 6.1 ± 0.6 6.3 ± 0.5 4.2 ± 0.9 8.6 ± 0.7
Sex hormone-binding globulin, nmol/l 24.6 ± 2.4 48.5 ± 3.9 28.0 ± 2.4 44.0 ± 4.0 19.7 ± 1.2

Table reproduced from Friedl et al.

In essence, these male Ranger students were in an energy deficient, near starvation state. Their reproductive hormone system is depressed. Testosterone levels fall through the floor, while SHBG increases to mop up hormone circulating in the serum. The thyroid gland decreases its activity, and the adrenals pump out additional cortisol. The biochemical milieu is catabolic. In this catabolic state, lean tissue (muscle) is burned for fuel. Fertility and reproductive drive are suppressed. This is the male equivalent of functional hypothalamic amenorrhea.

Not Just Elite Athletes

You might think that these aberrations only occur in extreme scenarios like in elite female runners being pushed to lose as much weight as possible, or in starvation conditions in Army Ranger School. But, a 2019 study of active duty military operators recruited from naval bases in San Diego demonstrated directionally similar biochemical abnormalities to those in Army Ranger School. Furthermore, if you visit one of the most popular sites ( for women with FHA, you’ll find dozens of stories of women who are neither elite athletes nor military operators, but women with regular jobs who are merely avid exercisers.

An Indication of How to Maintain Proper Energy Balance and Training Stimulus

While some people can improve strength and conditioning and lose weight simultaneously, others cannot. There are many factors that affect this equation. But, in general, an individual who is already relatively lean and well-trained may need to have a certain energy excess in order to devote biochemical resources to building new muscle, improving cardiopulmonary fitness, and maintaining mental, emotional, and reproductive function.

Power lifting champion, strength training expert, and exercise physiology PhD Layne Norton recently discussed the relationship between energy intake and the ability to build new muscle. He was asked about energy intake for a middle-aged man who is training to build muscle. Layne said, “the likelihood that he’s going to be able to gain lean mass without at least some body fat is probably pretty low.” He goes on to say that individuals who have been training for a long time need to have every element of training dialed in just to gain ounces of new muscle. Part of that equation is being in a caloric surplus, which means an individual might need to carry a little bit more body fat than they desire. These terms are necessarily vague, because they differ quantitatively on an individual basis. But, the point is, during periods of training during which a trained individual wants to improve performance, maintaining an energy surplus is important.

When women have a deficit between their nutrition, recovery, and the amount of physiologic and psychological stress they’re under, the hypothalamus and pituitary gland redirect energy away from reproduction. Gonadotropin-releasing hormone (GnRH), leutinizing hormone (LH), and follicle stimulating hormone (FSH) decrease, estradiol and androgens decrease. If the pituitary-gonadal system is depressed enough, the ovaries stop developing follicles and the endometrial lining thins out. Men obviously do not endure amenorrhea, but they do have an equivalent physiologic state. In my case, when I trained in excess of my energy intake and recovery ability, my symptoms were excessive fatigue, decreased exercise tolerance, and insatiable and unhealthy food cravings. My testosterone levels were low.

What can we do to avoid over-training and under-fueling?

Experienced athletes can often go by feel. One of the first things I notice when I’m applying too much stress and resting and fueling too little is that my will to train immediately declines. When I feel a strong physical aversion to exercise, I need to rest more and eat more. While it’s common to “not feel like exercising,” what I’m talking about here is different. For example, sometimes I’d be excited to be at the gym. On a cognitive level, I wanted to train. Then, I’d pick up some pitifully light weight, like 35 or 45 pounds, and it would feel like a monumental effort despite that I’d routinely lift between 200 and 300 pounds on certain lifts. This was a key physiologic sign that I wasn’t ready to train.

If performance is gradually declining, progress is stalling, libido is in check, or for women, menses becomes irregular or absent entirely, these are obvious warning signs to decrease training stimulus, increase rest and fuel, and possibly to seek medical attention to ensure that the diagnosis is mere over-training or under-fueling, and not an alternative diagnosis such as a cardiopulmonary problem.

For those of us with the interest and the will to quantify ourselves, there are many metrics we can track to monitor training load, fueling, and recovery:

  • Training volume and intensity
  • Performance (e.g. weight, reps, speed, etc.)
  • Resting heart rate and heart rate variability
  • Weight
  • Body composition
  • Caloric intake
  • Macronutrients and micronutrients
  • Hormone levels (e.g. LH, FSH, T, E2)
  • Perceived effort on a fixed exercise

Wearables like the Oura Ring and Whoop wrist band are helpful for athletes and avid exercisers to track recovery metrics. Cronometer is my preferred application for monitoring nutrition intake. I keep training logs. I weigh myself nearly every day and check labs at least twice yearly if not quarterly.

Ultimately, leanness, fitness, long-term health, performance, and aesthetics are objective values worth pursuing. But, when trying to push the boundaries of our physiology, it’s important to give as much attention to obtaining adequate rest and fuel as we do to training.


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