Running and Hormones

Everything You Need to Know About Running and Your Hormones

Nutrition and Diet

Curious about running and your hormones?

You’ve probably heard by now that hormones are responsible for regulating all of the processes that occur within our bodies. That includes regulating when we’re hungry, how well we sleep, and where we’re more likely to store fat. Since hormones regulate everything that we do, there is lots of potential for things to go wrong! The truth is, we’ve all probably suffered from some degree of hormone imbalance over the course of our lives. This blog will focus on the major hormones that regulate our appetite, body composition, and ability to recover from exercise. You will learn their function, signs of imbalance, and what you can do to help support balanced hormones, naturally!

What happens when our hormones are out of balance?

Hormone imbalances occur due to a variety of conditions. These include certain medications, tumors, thyroid conditions, stress, weight changes, hereditary conditions, and endocrine gland dysfunction among others. A hormone imbalance can create many undesired symptoms. These include weight gain in the midsection, reduced muscle mass, osteoporosis, skin conditions, disrupted periods, and hair loss. Although some of these causes may be out of our control, often lifestyle changes can help to alleviate symptoms.

Key hormones that can impact your running performance (and how you can optimize them!)

Leptin: Helps us Feel Full

Leptin is the hormone that tells us we are full. It is produced by the fat cells in our bodies. It travels through the bloodstream and acts on the hypothalamus in the brain. Leptin tells our brain that fat supply is sufficient, and we should stop eating. This should make it easy to avoid unwanted weight gain…right?

Unfortunately it isn’t that simple, and we have millions of years of survival adaptations to thank for it!

If we are carrying excess body fat, we may develop “leptin-resistance.” In other words, our body gradually starts to lose it’s sensitivity to leptin. Rather than increased in leptin levels reducing our appetite to a point where we naturally limit our calorie intake, we adjust to the higher leptin level and continue the same eating habits.

One way to increase feeling full is to eat a meal containing both protein and fat. When you eat a snack containing almonds and cheese, for example, it eventually enters the small intestine. Special cells lining the small intestine sense presence of fat and protein. This signals endocrine glands to release digestive hormones (including cholecystokinin (CCK), and peptide YY), that work together to slow digestion and reduce appetite. Mindful eating is another great tool for increasing feelings of fullness during meals. By taking the time to chew food thoroughly, you allow time for the food to enter the small intestine so that these hormones can act on your brain.

Ghrelin: The Hunger Hormone

Ghrelin is a hormone secreted by the stomach lining when our stomach is empty. Levels rise and fall in cycles every four hours throughout the day. Eating at regular times each day mimics this natural cycle. If we begin to lose weight, ghrelin levels start to increase, driving an increase in our appetite. Our bodies view weight loss as a threat to survival. It will attempt to restore balance to a “comfortable” weight (i.e. whichever weight we were maintaining before). This is what ultimately drives many people into the trap of “yo-yo” dieting. Using a slow, sustainable approach to weight loss can prevent us from being overwhelmed by hunger. This includes choosing foods that more filling- things that are high in protein or fibre which help to keep us full and satisfied for longer between meals.

Growth Hormone: The Fountain of Youth?

Ok, so “Fountain of Youth” may be a bit of an exaggeration, but human growth hormone has many positive effects on athletic performance and general wellbeing. Growth hormone (GH) is produced by the pituitary gland in the brain. It is released in bursts after exercise, trauma (for healing purposes), and sleep. GH increases protein production, and promotes fat use. Levels are highest in children, and decline from middle age onward. That is why lean body mass loss commonly occurs with ageing. GH also helps to balance blood sugar and cholesterol levels, and maintain proper brain function.

Symptoms of low GH include low sex drive, anxiety and depression, fatigue, sensitivity to cold and heat, and a tendency to store visceral fat (more on that in the next section). The good news is, you can stimulate the production of GH naturally by eating a balanced diet, getting enough protein, and prioritizing good sleep habits.

Intermittent Fasting (IF) & Growth Hormone

Who hasn’t heard of intermittent fasting at this point? Maybe you’ve tried it for yourself. I know several friends, coworkers and relatives who have implemented intermittent fasting as a weight loss strategy. Does it also work for muscle growth? Let’s look at the evidence.

Studies have found that growth hormone increases during periods of fasting. Although the mechanism is unclear, it is hypothesized that the purpose of GH secretion is to protect the loss of muscle and lean tissue. High quality studies in athletes are lacking at this point to determine if IF results in better performance outcome though. However, fasting has been utilized in the natural bodybuilding community due to the proposed muscle building benefits from the spike in GH.

Beyond the spike in GH, fasting has been found to have other health benefits. These include improving lipid profiles (lowering LDL, and total cholesterol), improving insulin sensitivity, better brain function, and activating natural detoxification pathways. Fasting mimics the ways humans have historically eaten. Distinct “fed” periods allow for optimal growth while distinct fasting periods support cellular repair and waste removal.

So, we should all totally be doing IF, right?

With all of the proposed health benefits of fasting, should you be doing it too?

Well, there are a few things you might want to consider!

First off, it’s important to note that you are likely already fasting without realizing it! Humans naturally fast overnight while we sleep. Assuming you sleep for 8 hrs, and don’t eat in the hour before bed or within an hour of waking up, you are fasting for 10 hours/day.

It’s also important to note that many of the health benefits seen with IF (improved lipid profile, better insulin sensitivity, cellular repair, decreased inflammation) are also observed with calorie restriction. Spacing meals approximately every 4 hours and eating at regular times during the day will help to create the “fed” and “fasted” environment the body needs to optimize growth and repair.

Also, fasting is not recommended for people with diabetes, eating disorders, women who are pregnant or breastfeeding, or people who struggle to maintain a healthy weight.

The Bottom Line on Fasting and Growth Hormone

While fasting has been shown to increase GH levels, there is no evidence that IF is superior to other methods of eating for muscle growth or athletic performance. It’s possible to get similar benefits from eating with circadian rhythms (i.e. eating during the day, fasting at night), and getting enough calories with the right proportion of macro and micronutrients. If you are an athlete, it is very important that you are eating enough calories during your feeding window. If you are consistently in a calorie deficit during intense training periods, performance and muscle mass will likely suffer.

Read more about intermittent fasting and athletic performance here!


Cortisol: The Stress Hormone

Cortisol is produced by the adrenal glands which sit on top of the kidneys. It regulates the stress response, better known as the “fight-or-flight” instinct. There are cortisol receptors all throughout the body. When our body senses a threat, increased cortisol levels signal the body to shut down certain nonessential processes such as digestion, immune function and growth. Ideally, cortisol levels should return to normal after the threat has passed. Unfortunately, many of us live under constant stress, meaning cortisol levels are chronically elevated.

Stress Affects our Food Choices

Stress can affect our weight and food choices. While some people tend to lose weight when chronically stressed, others may opt for high sugar, high fat (HFS) food choices as a coping mechanism (we may even crave them!). These highly palatable foods provide temporary relief from stress. However, research shows that stress combined with a HFS diet leads to weight gain disproportionate to the amount of calories consumed. In other words, it’s possible to gain more weight when you are stressed eating the same amount of calories than you would in the absence of stress.

prescription to reduce cortisol, stock image
It’s possible to have too much of a good thing. Cortisol is necessary for survival but too much is harmful over time.

Chronically elevated cortisol promotes visceral fat storage. Visceral fat wraps around the organs in the abdominal cavity, and is associated with increased risk of chronic diseases such as heart disease, diabetes, certain cancers and Alzheimer’s. The presence of visceral fat itself increases cortisol production in the tissues.

Chronic stress contributes to a seemingly never-ending list of health complications. Not only does it cause us to crave unhealthy foods, but also interferes with basic functions such as digestion (hello ulcers), weakens our immune system, and can lead to mood disorders and fertility issues. We now know that stress management is just as important for health as proper nutrition and exercise. Having a stress management strategy in place will not only help us to achieve our fitness goals, but also positively impact long-term health outcomes.

The Sex Hormones: Estrogen, Progesterone and Testosterone

Estrogen, progesterone and testosterone are the main sex hormones. Even though estrogen is the dominant female hormone and testosterone is the dominant male hormone, they are present in both sexes. Progesterone is a “helper” and mediates the effects of the dominant hormone. The sex hormones are produced primarily by the ovaries in women. In men, they are produced in the testes and adrenal glands. They work together for a variety of functions including maintaining bone health, fat metabolism, mood, brain function, skin elasticity, and heart health. Also, to their more commonly known sexual functions (libido, fertility, breast and prostate health, sperm production). These hormones naturally fall as we age.

When these hormones are out of balance, we may experience fatigue, weight changes and mood swings.

Testosterone (and to a degree progesterone) is responsible for helping us to metabolize fat and build muscles. It drops during middle age, which is why many people gain weight during this time. During menopause, a drop in estrogen for women causes symptoms including low sex drive, vaginal dryness, hot flashes, and bone loss. Low estrogen can also be caused by inadequate energy intake, too little body fat, or extreme training. Conversely, elevated estrogen can be driven by excess body fat, since some estrogen is also produced by fat cells.

Find out if you may be underfueling for the amount of training you’re doing.

Sex Hormone Imbalance

When estrogen and testosterone are not balanced, we might feel out of whack. Symptoms can include bloating, irregular or loss of periods, mood swings, anxiety attacks, hair loss, difficulty sleeping and fatigue. Men may experience infertility, erectile dysfunction and breast tissue growth. Over time, elevated estrogen is a risk factor for certain cancers, blood clots, and thyroid dysfunction. Although hormonal imbalances may be due to an underlying condition out of your control, some risk factors are within our control. Not surprisingly, these include maintaining a healthy weight and adequate muscle mass, and consuming a balanced diet. An endocrinologist can detect hormonal imbalances using a blood test.

The Bottom Line

Despite what you may have heard, there is no single “hormone balancing diet.” While certain herbal products or supplements may help you along the way, lifestyle changes have a much bigger impact on our body’s hormone balance. This means getting back to the basics of proper nutrition, and the right balance of training and rest. If any part of our fueling, training, or recovery strategy is out of sync we’re likely to run into issues with hormone imbalances.

So, start by giving your body what it needs to function optimally. This means having a solid nutrition strategy, a well-planned training program, with plenty of rest and recovery built in.

And, of course if an underlying medical condition has caused imbalances in your hormone levels, consult with an endocrinologist!


Are you ready to take your fueling, training, and recovery strategy to the next level? Apply for coaching today!

Running and Hormones
Maija Erickson
Maija Erickson

Maija is a recent nutrition and dietetics graduate from Boston, MA. She works as a personal trainer and has helped her clients to improve their running, skiing, and golfing performance through better exercise and nutrition habits.