How Do Hormones Work? Six FAQs About Hormones
Hormones have an incredibly powerful impact on every aspect of human life. They regulate sleep and wakefulness, dictate your mood, impact brain function, influence physical performance, and oversee your libido. They regulate fat burning and muscle building, playing a central role in body composition and weight management. Hormones also affect wellness, impacting risk of both acute and chronic diseases.
Despite the enormous influence of hormones on your day-to-day reality, there’s a good chance you may not know what they are or how they work. This is understandable since even university educated coaches and nutritionists rarely gain more than a vague knowledge of hormones during their professional training. This article fills the gap by giving you science-based answers to the most common questions people have about hormones presented in everyday terms you can understand.
What Are Hormones?
Hormones are chemical messengers that travel to specific areas of the body and cause a change to happen within the cells. Think of them as regulators, responsible for driving the many processes in the body.
You’ve probably heard of the most commonly known hormones, testosterone, estrogen, cortisol, and insulin. Testosterone is the male sex hormone, and a large surge in levels is what leads to the physical changes boys experience during puberty. It’s the high level of testosterone that allows young men to pack on muscle so easily.
Estrogen is the female sex hormone, acting in a similar way in girls by triggering physical changes during puberty. It’s the monthly fluctuations in estrogen that lead young women to experience a menstrual cycle.
Cortisol is a critical metabolic hormone that frees energy stores from fat and muscle to be burned during times of stress, such as lack of food (fasting). A sharp rise in cortisol before dawn is what gives you the energy to get out of bed in the morning.
Insulin is another metabolic hormone that helps the body use glucose for energy inside of cells. It’s insulin that allows your cells to extract the energy derived from carbs and other foods to power physical activity and repair tissue.
How Are Hormones Made?
Hormones are released by glands throughout the body. The thyroid gland is one example: It makes and releases thyroid hormones, which travel to target tissues via the blood. Things get a little complicated when you get into the details—for example, there are two types of thyroid hormone, T3 an active form, and T4 an inactive form that must be turned into T3 by kidneys and liver—but we’re going to try to keep things relatively simple in this article.
Here is a list of the most important glands and the hormones that they produce:
- The adrenal glands produce cortisol and other glucocorticoids
- The pituitary gland produces growth hormone and oxytocin
- The pancreas releases insulin and glucagon
- The testes in men release testosterone
- The ovaries in women release estrogen and progesterone
- The pineal gland produces melatonin
- The hypothalamus in the brain produces hormones that signal other glands to produce hormones in a cascade-like fashion.
What Are Hormones Made From?
Hormones are made from raw materials that you get from your diet. This means that to a certain degree, it’s possible to impact hormone levels based on what you eat. For example, the mineral iodine is necessary for the thyroid to produce thyroid hormone. Iodine is mainly present in seafood and plants grown in iodine-rich soil. Historically, populations that live inland, far from the ocean, often had diets that were deficient in iodine, leading to low thyroid function and the problems associated with it. Today, salt is often fortified with iodine to counteract this problem.
There are three main types of hormones, each made from different raw materials:
Steroids are made from cholesterol and include testosterone and cortisol. They are fat-soluble and they passively diffuse into the cell, which means your body doesn’t have to spend any energy getting them where they need to go. Another interesting thing about steroids is that they are not stored in the body but are synthesized on demand when needed. Steroid hormones are attached to protein carriers that make them inactive until they reach the target tissue. These two factors make them have a slower action than their counterpart, amino acid-derived hormones.
Amines are simple molecules made from the amino acids tyrosine or tryptophan and include melatonin and epinephrine.
Peptides are made from chains of amino acids and include growth hormone and insulin.
Amines and peptides are different from steroids in that they are stored until the signal is received for secretion. Unlike steroids, peptides and amines are freely transported in the bloodstream, which allows them to have a rapid action.
How Are Hormones Regulated?
Many hormones in the body are regulated by the control center in the brain, called the hypothalamus. The hypothalamus is part of the endocrine system, which produces hormones, and the nervous system, which automatically regulates many of your body’s functions, such as heart rate and blood pressure. The purpose of the hypothalamus is to keep everything working properly by maintaining homeostasis.
An important thing to understand about hormones is that they often work in a cascading fashion, whereby a number of glands signal each other in sequence. A group of glands that signal each other is called an axis. For example, the hypothalamic-pituitary-adrenal axis (HPA axis) results in the release of cortisol from the adrenal gland following a cascade of signals that start in the hypothalamus:
The hypothalamus release corticotropin releasing hormone (CRH) in response to a stressor, which stimulates the pituitary gland to release ACTH. ACTH is released from the pituitary, which travels to the adrenal glands to stimulate release of cortisol. Cortisol is then carried in the blood to target tissues, including fat and protein stores, to raise blood glucose.
Another important axis is the hypothalamic-pituitary-gonadal axis, which regulates release of testosterone and estrogen from the gonads (testes or ovaries depending on the sex of the individual). In this case the hypothalamus release gonadotropin-releasing hormone (GnRH), which travels to the anterior pituitary to stimulate the release of follicle stimulating hormone (FSH) and luteinizing hormone (LH), which travel to the gonads to stimulate release of testosterone in men and estrogen in women.
It should be noted that men require small amounts of estrogen, which they make through the process of aromatization, whereby the aromatase enzyme transforms testosterone to estrogen. Women also require testosterone, which they get from the adrenal glands.
The thyroid, which regulates metabolism among other things, is also stimulated by a cascade that starts with the hypothalamus. The hypothalamus releases thyroid releasing hormone (TRH), which alerts the pituitary to produce thyroid stimulating hormone (TSH). TSH travels to the thyroid, where it tells it to produce the two forms of thyroid hormone: T3, an active form of thyroid hormone, and T4, an inactive form that is transformed into the active T3 form by target tissues.
Hormones work as part of feedback loops. A negative feedback loop occurs when the secreted hormone travels back to decrease further secretion from the gland. Cortisol provides a perfect example of how a negative feedback loop is supposed to work: Your hypothalamus senses that you are experiencing stress and it releases CRH triggering ACTH to be released from the pituitary, leading to cortisol release from the adrenals.
As cortisol enters the blood stream it stimulates epinephrine, which activates the sympathetic nervous system and turns on your flight or fight response. At this point, you should feel ready to take action—whether to crush a heavy set of deadlifts, outsprint an opponent, win a verbal fight, or solve a difficult mental problem at work. Hunger will be absent and you’ll feel no pain.
At the same time that all this is happening, your hypothalamus and pituitary will sense the high cortisol levels, and shut off release of CRH and ACTH release. This will allow cortisol to go down, leading to a drop in epinephrine activity, gradually calming you down.
How Do Distinct Hormones Interact With Each Other?
Sometimes, hormones will behave differently depending on the environment they are in. For example, in the right situation, such as when it spikes during an important competition, cortisol burns fat and gives you energy. But when it is chronically elevated in response to stress and paired with high insulin after eating a burger and fries, it causes fat storage, mainly in the abdominal area. It’s this combination of high insulin and cortisol that leads middle-age fat gain around the waist and the unfortunate “dad bod.”
Another example is how insulin affects appetite: After eating a meal containing carbohydrates, blood glucose (also known as blood sugar) increases, which leads the pancreas to release insulin to allow glucose entry into your cells to be burned. When insulin and blood sugar are both elevated, a satiety signal goes to the brain, dampening hunger and making you feel full. However, when high insulin is paired with low levels of glucose in the blood (as in diabetics or prediabetics), it stimulates appetite and makes people hungry. This is an unfavorable environment that predisposes you to overeating and obesity.
What Can I Do Today To Optimize Hormones?
Optimal hormone balance can make or break an elite athletes ability to perform. It dictates how you feel during the day, impacting mood, mental outlook, resilience, and perseverance. It regulates appetite, metabolism, and food cravings. It affects your ability to recover from intense exercise and sleep at night.
It’s safe to say that to some extent, making sure hormones are at optimal levels is a secret to success. The good news is there are four basic actions you can to take to optimize hormones:
Lack of sleep has a profoundly negative effect on hormone balance, raising cortisol, altering insulin sensitivity, lowering testosterone and growth hormone, and impairing release of epinephrine and norepinephrine. Solving lack of sleep will require different actions depending on your situation. The first step is to establish good sleep habits: Have a set bedtime, sleep in darkness, and avoid electronics before bed.
There’s even some evidence that people recovering from HPA axis dysfunction do best getting up later in the morning—around 8 or 9 rather than 6 or 7—so you might want to try it if it’s an option. The second step is to overcome insomnia or a racing mind—enter #2, stress management strategies.
#2: Cope With Your Stress
The hormonal system is designed specifically to help you combat acute stressors, such as a lack of food, a dangerous predator, or an injury. What your body is not designed to cope with is the chronic all-the time stress that many people in modern life experience from poor diet, lack of physical activity, traffic, the internet, financial worries, long work hours, and so on. In this situation, cortisol becomes chronically elevated, depleting testosterone and other sex hormones. The fight-or-flight system is always turned on, negatively impacting blood pressure and heart function. Often, inflammation develops, and the hypothalamus is no longer able to effectively regulate hormone release throughout the body. Exercise, meditation, working with a therapist, having fun, and forging a supportive social network are a few of the actions you can take to manage stress and allow your hypothalamus to do its job.
#3: Optimize Nutrition
There are several ways your diet impacts hormone levels. First, food provides the building blocks for the body to produce hormones. Second, certain dietary nutrients are necessary for the body to be able to metabolize excess hormones (magnesium and vitamin C allow the body to clear cortisol once it is no longer needed). Third, refined foods and excess sugar spike insulin, harming metabolic function and throwing off hormone balance throughout the body.
Optimizing nutrition for hormone balance is complex topic, which is why we wrote this article to lay out all the detail, but here’s the short version: Design meals around high-quality protein, healthy fat, and low-carb vegetables, swapping out processed or refined products for foods in their most natural state: Seafood, meat, eggs, nuts, dairy, vegetables, fruit, seeds, and select grains.
#4: Train Smart
Lack of physical activity has a profoundly negative effect on hormones, raising cortisol and insulin and lowering testosterone and growth hormone. When combined with an unhealthy diet, it may even disrupt the ability of the hypothalamus to regulate hormone levels. Studies suggest that intermittent forms of exercise such as weight training and sprint intervals can reset the HPA axis so that it becomes more responsive and cortisol balance improves. The key is to not overdo it with two-a-day workouts or long, intense cardio sessions. Two to four weight workouts and two short interval workouts of less than 25 minutes a week will do the trick for most people.