How Cardio Affects Hormones and Weight Loss

Vicki Witt
Apr 23
5 min read

When you’re trying to lose weight, one of the first things you might turn to is exercise. You might head to the gym and hop on an exercise bike, and feel pleased with all the calories the machine tells you you’ve burned.

But is this actually helping you lose weight?

In this blog post we’ll look at how cardiovascular exercise affects your hormones and how to get the most out of it so you can lose weight.

What is cardiovascular exercise?

Cardiovascular exercise or cardio is exercise that uses your cardiovascular system, primarily your heart and lungs. Your heart rate will be elevated to some extent and your breathing will intensify.

Cardio can be steady state (same intensity throughout the exercise period) or intervals (periods of higher intensity mixed with lower intensity).

How does cardio affect hormones

Let’s start by taking a deep dive on how cardio affects your hormones. Here are some of the hormones that are affected by cardiovascular exercise.

Cortisol

Cortisol is the stress hormone and it can cause health issues and weight gain when levels are chronically high.

Cardio exercise will raise your cortisol levels while doing the exercise. But cortisol levels will usually return to baseline levels. Over time regular cardiovascular exercise can help your body adapt to stress and reduce your baseline cortisol levels. The key is to limit high intensity exercise as this can increase cortisol levels. Long duration exercise also has detrimental effects on cortisol levels. Exercising outdoors, especially in nature has a positive effect on your stress and cortisol levels.

Testosterone

Testosterone is important for men and women for maintaining muscle and bone. Adequate testosterone levels also help you to maintain your weight.

Cardiovascular exercise does not help to boost testosterone in either men or women. And if too much cardio is done, this can reduce testosterone levels. For women with PCOS this can be beneficial, but generally this is not desirable.

Estrogen

Estrogen is one of the female sex hormones. Both men and women have these hormones and the balance of these hormones along with testosterone levels is important for health and for maintaining a healthy weight.

In post menopausal women anaerobic exercise which includes cardiovascular interval workouts increases estrogen levels. Steady state cardio has no effect on estrogen levels for this cohort. For premenopausal women a moderate amount of cardiovascular exercise lowers estrogen level, keeping the estrogen to progesterone ratio more balanced. This helps to lower the effects of estrogen dominance and lower breast cancer risk.

In men cardiovascular exercise, especially high intensity or endurance exercise can increase estrogen levels while potentially lowering testosterone levels. This can lead to a state of estrogen dominance.

Insulin

Cardiovascular exercise has a positive effect on insulin sensitivity. This is especially important for those with insulin resistance. This helps to keep insulin levels more stable which can lead to weight loss, and lowers the risk of developing Type 2 diabetes.

Thyroid hormones

Too much and too high intensity cardio can cause thyroid hormone imbalance and hypothyroidism especially in men. Since the thyroid controls metabolism this can have a detrimental effect on those those trying to lose weight with excessive and intense cardio. Moderate intensity and duration cardio has less of an effect.

If you already have hypothyroidism exercise can help to manage symptoms and should be included. Just keep it to a lower intensity and low impact.

How does cardio affect weight loss?

Cardiovascular exercise has less of an effect on weight loss than most people think. There are several reasons for this.

The calorie burn from a normal cardio session is not enough to make a large difference
Longer or very high intensity cardio sessions have a detrimental effect on hormones for many people
People often “reward” themselves with a calorie dense, post workout, snack

However cardio is an important part of a weight loss regimen if done correctly. The benefits will add up over time. Moderate cardio exercise especially done outside helps to relieve stress, balance hormones and improve health.

Mental Health Benefits

The mental health benefits of cardiovascular exercise are well known. Regular cardio can help to relieve anxiety and depression. It can help to keep cortisol levels in balance. It can also help to release endorphins that improve mood. It also increases mood boosting serotonin.

But too much cardio can lead to lower testosterone levels which can increase the risk of depression.

What should you do

Most benefits of cardiovascular exercise come with moderate duration and intensity exercise. Too much and you run the risk of causing hormone imbalances that are detrimental to your health. High intensity cardio like HIIT is not recommended due to the detrimental effects on several hormones.

If you are doing long duration cardio then stick to lower intensity exercise like walking, hiking or easy cycling to avoid hormone disruption.

If you are starting out with exercise it’s important to not start with exercise that is too intense. Make sure to keep the duration short to start. This will help you avoid the hormonal impacts of higher intensity or long duration exercise while gaining the benefits of cardiovascular exercise for overall health and well being. Keep in mind that what might be easy for some can be a very intense workout for beginners.

The right amount of cardiovascular exercise has many benefits for hormone health and overall health. Even a 10 minute walk will have benefits. Increase these benefits by getting outside if you can.

"Vicki is so knowledgeable about nutrition, hormones, how foods work to help you not only lose weight but also to feel wonderful. With Vicki's help, the minor arthritic pain I have experienced in my hands is gone. My energy level has increased, my body temperature has normalized, and best of all...I have had very successful weight and body fat loss and have lost several inches in my waist and hips, all in just 4 short weeks." - Susie ID

How I can help

I can help you come up with an overall plan for your diet and lifestyle which will help you to balance hormones and lose weight. Exercise is an important part of that and together we can come up with a plan that is best for you and your unique body.

Book a free nutrition assessment

Warm wishes,

About Vicki:

Vicki Witt is a Clinical Nutritionist, Holistic Health Coach, and Reiki Master. She has been practicing over 25 years and specializes in holistically customizing diet and lifestyle plans to each individual for weight loss and hormonal control. Her clientele often report they feel the best they have ever felt and wish they had started sooner. One of the USA and Australia's top Nutritionists, she has won multiple awards for her services in the industry.