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Science What is Interleukin-6 and How Can It Improve Your Health?

This secret superhero of strength training can fight chronic inflammation, burn fat, and build muscle.

Showing the interleukin-6 protein in the muscle of a man working out on Tonal.

There aren’t many instances where something works for you and against you at the same time in your body. Interleukin-6, a protein released in the body, is one of those instances. Some researchers have even gone as far as to compare it to the dual nature of Dr. Jekyll and Mr. Hyde. 

This double-duty protein has many functions in the body and while it gets a bad rep most of the time, the gains you’ll get from the exercise-induced version may surprise you. Here, we’ll explore what interleukin-6 is, how it can improve your health, and how strength training can help you reap those benefits. 

What is Interleukin-6? 

Interleukin-6 (IL-6) is a type of protein produced by the body as part of the immune response (think: when your ankle swells up after rolling it or your fever spikes during an infection). It also hangs around when you have chronic inflammation, a constant low-level state of tissue breakdown that is tied to chronic conditions such as type 2 diabetes and heart disease. But there are some powerful benefits of IL-6, depending on what tissues produce it. 

A comprehensive review published in Physiological Reviews reveals that there are two places IL-6 is produced in the body:

  • The pro-inflammatory IL-6 (Mr. Hyde–the bad one) is produced In the fat tissue (called a cytokine) and increases chronic inflammation, breaks down muscle tissue, and increases chronic and acute health risks. 
  • The anti-inflammatory IL-6 (Dr. Jekyll–the good one) is produced in the muscle tissue (called a myokine), and decreases chronic inflammation, preserves muscle tissue, and offers additional health benefits. 

This is where strength training comes into the picture. Lifting weights can release the myokine (anti-inflammatory) IL-6 which leads to the following health and performance benefits.

What Are the Benefits of Exercise-Induced Interleukin-6? 

Fights inflammation and Chronic Diseases

Exercise spikes inflammation levels in the short term, flooding the body with anti-inflammatory (myokine) IL-6 so you can achieve lower levels of inflammation after your workout and throughout the day. In a large review including over 75,000 participants, researchers found lower levels of muscle mass and strength are associated with higher resting inflammatory markers. 

Think about it like this: Exercise raises your heart rate in the short term, but consistent exercise over time lowers your resting heart rate. The same goes for the inflammatory response during strength. In fact, in a study published in Nutrition Research and Practice, a single strength training session showed an acute increase in inflammation levels with the workout but lower levels of inflammatory markers at rest. 

Chronic inflammation is like a gas stove left on at a low burn (and what you’re burning is most likely muscle), says Stuart Phillips, PhD, Professor of Kinesiology at McMaster University. “Exercise does, acutely, turn up the burner, but the adaptive response is to get better at handling that acute inflammation, and then suppress and lower the resting levels of inflammation.” The IL-6 released from your muscles in your workouts makes you more efficient at reducing inflammation throughout the rest of the day. 

Reducing chronic inflammation means reducing your risk of chronic disease. Research suggests the IL-6 released from muscle has powerful benefits for metabolic and cardiovascular health such as improving insulin sensitivity and reducing inflammatory markers of cardiovascular disease.

Protects from Acute Illness

When you’re sick or injured, there’s a magnified immune response triggered in the body. While an acute response is essential for healing, too much of a good thing can start to cause damage. For example, the Covid-19 infection creates a “cytokine storm” in some patients, which leads to severe illness. 

“We know that muscle supports more than just movement; it acts as an endocrine organ by releasing myokines like interleukin-6,” says Hamilton Roschel, PhD, Head of the Applied Physiology and Nutrition Research Group at University of São Paulo. “IL-6 benefits the body in different ways, but in particular, it can help to mediate the immune response.”  

Maintaining muscle mass and strength through resistance training can have a protective effect on your health because when you do have an acute response, your body can get back to normal, quicker. This may explain why more muscle mass and strength was linked to lower severity of Covid-19

Burns Fat and Builds Muscle 

The benefits of IL-6 go beyond fighting illness. Research shows the IL-6 released by muscles during exercise may also help break down fat and build hypertrophy. This happens through improved metabolism and insulin sensitivity–you’re able to use food for fuel and produce energy more efficiently. 

High-intensity activities and strength training workouts tend to use up your glycogen, the stored carbohydrates in your body. As a result, your body releases IL-6 from muscle. This sparks a search for a new form of energy, pulls in other nutrients to the cell, and signals fat cells to break down to be used for fuel. This fat breakdown signaled by the IL-6 might explain why regular resistance training gives you a leg up on reaching your body composition goals, reducing your body fat in the process. 

What’s even better: IL-6 released from muscle can also fast-track muscle growth. A recent review describes how IL-6 from muscle activates pathways within the muscle cell that lead to improved muscle hypertrophy and muscle function. 

How Can You Reap the Rewards of Interleukin-6? 

You can gain the protective effects of muscle and IL-6 with exercise, according to Boris Cheval, PhD and Matthieu Boisgontier, PhD, researchers at University of Geneva and University of Ottawa respectively. They note that research continues to point toward an essential role of IL-6 in health protection and the benefits of engaging in physical activities that build muscle and stimulate the release of IL-6. And resistance training is essential for building muscle (hypertophy)–which can give you an edge with IL-6.

Tonal makes it easy to accomplish hypertrophy goals with programs that support the “Build Muscle” goal. Progressive overload is built into your workouts with digital weight so your muscles are consistently challenged and in turn, continue to release IL-6. Squeezing in just two to three workouts a week of strength training can boost serious health benefits, including harnessing the protective effects of IL-6. 


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