Your Calf Muscles: The Second Heart You Never Knew You Had

Every step you take is helping more than you probably realise.

Have you ever heard someone call your calf muscles your second heart?

It sounds a bit dramatic.

After all, you only have one heart… don’t you?

Well, yes.

But your calf muscles do perform one incredibly important job that your heart simply can’t do on its own.

They help push blood back up from your feet towards your heart.

And if you’ve been sitting for hours, they don’t get much chance to do it.

Your heart pumps blood out. Your calf muscles help bring it back.

Your heart pumps oxygen-rich blood around your body through your arteries under pressure.

Getting that blood back again is much harder.

The veins in your legs have to move blood upwards against gravity.

Fortunately, they have help.

Every time your calf muscles contract while you walk, climb the stairs or even rise onto your tiptoes, they gently squeeze the deep veins that run through them.

Tiny one-way valves stop the blood slipping backwards.

Each squeeze gives it another little push towards your heart.

Scientists call this the calf muscle pump, and it’s one of the main reasons walking is so good for your circulation. Research has consistently shown that walking activates this natural pump far more effectively than simply standing still.

Could muscle loss play a part?

This is something I’ve been wondering about.

As we age, we naturally lose muscle mass and strength—a process known as sarcopenia. If we also become less active, our calf muscles aren’t working as often or as effectively.

I can’t help wondering whether this is one reason swollen ankles become more common as we get older.

The research doesn’t suggest sarcopenia is the only cause of swelling, but it does show that regular calf muscle activity is vital for healthy circulation. It also suggests that older adults who keep moving may preserve this natural pump better than those who become increasingly sedentary.

Fi Clnical Pearl

Unless we actively challenge our muscles, this begins surprisingly early and accelerates after about the age of 50.

At the same time many people also become less active.

Less walking.

More sitting.

Fewer stairs.

Less confidence.

Perhaps a painful knee or hip.

The calf muscles therefore have less opportunity to contract, and if they’ve also become smaller and weaker, the calf muscle pump may not work as effectively as it once did.

That combination could contribute to more pooling of fluid in the lower legs, especially in people who already have venous disease, lymphatic compromise or spend long periods sitting. This is physiologically very plausible and fits what we know about the calf muscle pump, although it’s better supported as a contributing factor than a sole cause.

I actually found something fascinating…

There was a study where researchers mechanically stimulated the calf muscle pump in women who tended to develop fluid pooling while sitting.

The extra calf pump activity reversed the pooling.

The researchers suggested that, in many people, lower-limb swelling may partly reflect inadequate calf muscle pump activity or tone rather than fluid simply “building up.”

Even more interesting…

Older adults who spend more time sitting are much more likely to develop chronic lower-limb oedema, while those who remain active tend to preserve calf muscle pump function better. One MRI study found that ageing itself didn’t necessarily reduce the muscle pump in people who maintained regular exercise habits.

To me, that’s hopeful.

It says:

Keep moving.

Not because ageing is inevitable…

…but because movement helps preserve one of the body’s natural pumps.

“As we age, many of us lose strength in our calf muscles and become less active. Together, these changes may reduce the effectiveness of our natural calf muscle pump, making it easier for fluid to collect around the ankles—particularly in people who already have venous or lymphatic problems.”

Sitting changes the picture

When we’re walking, this pumping system works beautifully.

When we’re sitting for long periods…

…it becomes much quieter.

Blood can begin to collect around the ankles.

You might notice your socks leaving marks.

Your shoes fit perfectly in the morning but feel tight by teatime.

Your legs feel heavy or tired.

Every clinic day I hear little comments like these.

People often assume it’s simply part of getting older.

Sometimes it’s just their body asking for a little more movement.

The answer isn’t always harder exercise.

Often it’s simply more frequent movement.

It isn’t only about blood

This is the bit I find fascinating.

Your lymphatic system also depends on movement.

Unlike your heart, the lymphatic system doesn’t have one central pump.

Instead, lymph moves because of muscle contractions, breathing, changes in body position and all the little movements we make throughout the day.

Your calf muscles are part of that story too.

That’s one reason many people say they feel lighter or less stiff after “just a little walk.”

It’s not your imagination.

Your body was designed to move.

The muscles nobody thanks

I often joke that your calf muscles are probably the hardest-working muscles nobody ever thanks.

They quietly get on with their job every time you walk to the kettle.

Climb the stairs.

Stroll around the supermarket.

Walk the dog.

Dance in the kitchen.

They don’t ask for much.

Just the opportunity to move.

A little clinical pearl

When I work with people living with swelling, recovering after surgery or following cancer treatment, we spend a lot of time talking about movement.

Not because movement fixes everything.

It doesn’t.

But movement supports so many of the body’s natural systems.

Sometimes the most effective exercise isn’t the hardest.

It’s simply the one you’ll actually do.

The takeaway

Your heart never gets a day off.

Neither do your calf muscles.

The more regularly you use them, the more regularly they help your circulation.

You don’t have to move perfectly.

You don’t have to move for hours.

You simply need to keep reminding your body that it was designed to move.

Sometimes the healthiest thing you can do isn’t another workout.

It’s simply taking the next step.

Fi’s One Minute Takeaway

Today, give your second heart a little workout.

Walk while the kettle boils.

Rise onto your toes ten times.

Take the stairs if they’re there.

Park a little further away.

Your circulation doesn’t care how far you walk.

It simply loves that you moved.

If you have more questions leave me a comment or please get in touch if you would like to find out about my movement sessions or treatments. 

If you would like to read more:

• Why your lymphatic system loves movement

• Sometimes the Best Medicine Wears Walking Shoes

• Can Breathing Help Your Lymphatic System?

On the Shoulders of Giants

The idea of the calf muscle pump has been recognised for decades in vascular medicine. Research continues to show that regular walking and calf muscle activity improve venous return, while the lymphatic system relies on muscle contractions, breathing and changes in body position to help move lymph around the body. Every step really does contribute to the remarkable systems that keep us healthy.

Further Reading

• Delis KT, Nicolaides AN. The calf muscle pump and chronic venous disease.
• Browse NL, Burnand KG, Irvine AT. Diseases of the Veins.
• Mortimer PS, Rockson SG. New developments in clinical aspects of lymphatic disease. Journal of Clinical Investigation.
• International Society of Lymphology. Consensus Document on the Diagnosis and Treatment of Peripheral Lymphoedema.