Building lean muscle has been boasted for reducing fat and toning the body, but it’s seldom discussed in relation to the immune system. Lean muscle is a powerful medicine and has a protective effect for our immune systems.

The Evidence

In studies of mice it has been observed that mice with more muscle fare best when fighting a chronic viral infection. Many chronic illnesses like infections and cancers exhaust the immune system, but in muscular mice the skeletal muscle tissue releases cytokines. This small protein triggers a phenomenal reaction. The cytokines influence “T-cell precursors” to settle within the muscle, creating a sort of back up reserve of cells that can migrate out and develop into fully-functional T-cells when needed. Thus, when the immune system’s regular T-cells are too exhausted to support the body in the face of chronic illness, the precursor cells get released from muscles and become new, disease-fighting T-cells at the sight of infection.

(I don’t know about you, but when I learn something like this about the body I REALLY geek out!)

While this specific protective mechanism between the immune system and muscles has only been proven in studies on mice, there’s a strong chance the same thing happens in our bodies. For example, it has been known for a while that immune cells play a critical role in repairing muscle. This is called myogenesis. In this process, immune cells help regulate stem cells within the muscles to regenerate healthy tissue. The immune system’s critical role in muscle growth and repair may help explain why muscle mass diminishes with age. In other words, the aging immune system results in reduced muscle stem cell function.

In another study, people who regularly bicycled had more immune cells thanks to their muscle mass. Their muscles produced more hormones to regulate the thymus, the organ where T-cells are manufactured (these little fighters help detect infections, including covid-19). The cyclists’ bodies also produced more cancer-protective proteins like the interleukin-6 protein (IL-6).

In summary, the muscle-immunity connection is very real. Now, let’s talk about how to take advantage of it…

How to Maintain Muscle

First off, please don’t feel upset if you don’t look muscular. You don’t have to flaunt a six-pack or chiseled legs to be strong and healthy. Bodybuilders and fitness models have lots of lean muscle, it’s true, but they also have very low BMIs. In other words, they work extremely hard to trim down fat. Sometimes, this can be to the detriment of women’s health if they become amenorrhoeic (i.e. their menstrual cycle stops), so try hard not to compare your body to someone else’s. Perfectly normal people can have immune-fighting and health-boosting muscle mass while also retaining healthy amounts of fat.

In general, I recommend for healthy people under the age of 40-45 to focus on exercises that are moderately intense for 45 minutes/day, 4-5x/week to maintain good health and lean muscle mass. Other days of the week can be used for rest days, low-intensity exercise days, walking, stretching, gentle yoga, meditation, gardening/yardwork, cleaning the house, or other light activities. Adults over 45-years old can follow the same framework but should keep exercise bouts lower in intensity. This programming is extremely basic but demonstrates how weekly exercise can be scheduled for general fitness and muscle maintenance.

You can build strength and muscle through virtually any exercise; running, low-impact cardio, HIIT, strength training, dance, swimming, sports, yoga, pilates, barre, you name it. It’s all fair game. What matters the most is that you regularly stimulate and stress your body (in a good way, of course) with exercises that get your heart rate up and challenge your efforts. As long as this is done safely then you can enjoy many lifelong benefits for your overall health.

Strength Train at Least 2x/week

Although it might be out of your comfort zone, I recommend that everyone (yes, everyone) do strength training twice a week.

Why?

Strength training offers focused bouts of effort that can allow you to train weak areas of your body to improve overall strength, balance and postural support. Incorporating strength training into your weekly regimen (even if you only do 20 minutes twice a week) will allow you to troubleshoot weak muscles so that the exercises and sports you enjoy the most can be enjoyed for years to come.

While performing strength training exercises, the number of sets and reps needed is highly subjective to your level of fitness, ability to maintain form, and knowledge of the movement pattern. Whether you choose to use free body weight exercises, weight machines, or props is also dependent on your individual needs. You can gain enormous benefits from any and all of them. For a highly detailed tutorial about strength training, check out my contribution to a MyFitnessPal article on the topic: Fitness Basics: Strength Training.

You deserve to feel amazing in your body. A little muscle might help. This doesn’t mean that you have to be excessively skinny or lacking fat. It doesn’t even mean that you have to be super strong! Feeling amazing is a balance that only you can define and at its heart is wellness.

Yours in health and wellness,

Maggie