💪 How your muscles talk to the rest of your body

Muscles aren’t just for movement; they’re powerful communicators

Every time you contract a muscle, it releases special signalling molecules called myokines

These tiny messengers travel through your bloodstream, influencing everything from your metabolism and immune system to your brain and mood

Myokines act both locally (within the muscle) and systemically (throughout the body), helping explain why regular exercise benefits so many aspects of health

7 Notable myokines

Here are some of the most studied myokines and what they do:

1. IL-6 – Regulates inflammation and energy metabolism.

2. Apelin – Improves glucose uptake and supports cardiovascular health.

3. Irisin – Encourages fat cells to become more metabolically active (a process called “browning”).

4. IL-15 – Promotes fat burning and helps maintain lean muscle mass.

5. BDNF – Boosts brain plasticity and cognitive function.

6. Decorin – Aids muscle growth and repair.

7. FGF21 – Supports healthy glucose and lipid metabolism.

🥊 Summary

Exercise isn’t just about burning calories or building strength; it’s a chemical conversation between your muscles and your entire body. Every rep, step, or stretch sends signals that help modulate your health.

🧠The muscle–brain axis: How exercise supports better sleep

We all know that exercise is good for the body

But did you know your muscles also talk to your brain?

And that this conversation might help you sleep better?

Recent research has uncovered a fascinating link between muscle activity and brain health, especially in how it affects sleep quality

This connection is part of what scientists call the muscle–brain axis: a two-way communication system where your muscles send signals that influence brain function, mood, and now, sleep.

The science behind it

When you move your body your muscles release special molecules called myokines (check pervious article)

A new study published in Nature (2024) shows that one particular myokine, called neurturin, plays a key role in this process

Neurturin is released by slow-twitch muscle fibres (the kind used in endurance activities like walking or cycling)

Once released, it travels to the brain and helps regulate neuronal activity in areas that control sleep

Researchers discovered that Neurturin:

• Improves sleep architecture, both structure and quality of sleep cycles

• Enhances non-REM sleep, which is crucial for physical recovery and immune function.

• Improves sleep patterns and improve stable brain activity during rest (in mice)

🥊 Summary

Regular physical activity doesn’t just tire you out, but it actively helps your brain create the conditions for deeper, more restorative sleep.

💪 Muscle as your metabolic and immune powerhouse

Muscle plays a central role in how your body manages energy and defends itself against illness

A recent study explores how skeletal muscle acts as a dual-function organ…

…influencing both metabolism and immune responses in ways that are vital for overall health

Muscle and metabolism

Muscle is the body’s largest site for glucose uptake

Meaning it helps regulate blood sugar levels

When you move, your muscles use glucose for energy, improving insulin sensitivity and reducing the risk of type 2 diabetes

But that’s just the start. Muscle also:

• Stores amino acids for tissue repair and hormone production

• Releases myokines: a messenger molecules that influence fat burning, appetite, and even liver function

• Helps maintain a healthy basal metabolic rate, which is the energy your body uses at rest

🧬 Muscle and immunity

Muscle also actively supports immunity

The study highlights how muscle tissue:

• Produces immune-modulating myokines like IL-6 and IL-15

• Acts as a reservoir for glutamine, an amino acid essential for immune cell function

• Responds to inflammation by adjusting its own metabolism and signalling pathways

This means that maintaining muscle mass, especially as we age, can help keep the immune system resilient and responsive

🥊 Summary

Muscle health is not just about looking fit, it’s about staying well, especially as we age. You muscles are metabolic and immune systems regulators. Every time you exercise, you’re activating a system that helps your body stay balanced, energised, and protected.