Our Second Heart Is in Our Legs: Why the Calf Muscles Matter for Blood Circulation, Health, and Metabolism

We invest time in strengthening the abdominal muscles, glutes, thighs, and arms.

But there is one muscle group that in my opinion does not receive enough attention, although it works for us almost every moment we stand or walk.

The calf muscles.

We are used to thinking of them as the muscles allowing us to rise on our toes, walk, run, or jump.

But their role is much more significant.

In fact, the calf muscles are part of an important mechanism helping blood return from the legs to the heart.

This mechanism is known by the name the calf muscle pump, and it is sometimes also called "the second heart" or "the peripheral heart."

This does not mean we really have an additional heart in the body.

But once we understand how this mechanism works, it is easy to understand why leg movement is so important to our health.

Why is an additional pump needed in the legs at all?

Our heart pumps oxygen-rich blood through the arteries to the tissues and organs in the body.

After the blood passes through the small blood vessels in the tissues, it returns to the heart through the veins.

But when we stand, the blood located in the feet and calves needs to return upward, against gravity.

And this is not a simple task.

To assist this process, the body uses several mechanisms.

One of the important ones is the contraction of the muscles around the deep veins in the legs.

When we walk, climb stairs, or move the ankles, the calf muscles contract and press on the veins.

This pressure helps push the blood upward.

Inside many veins there are one-way valves helping prevent the blood from flowing back toward the feet.

And so, with every step we take, we activate a mechanism helping return the blood to the heart.

This is one of the reasons the calf muscles received the nickname "the second heart."

Meet the two central muscles in the calf

In the back part of the calf are two especially important muscles.

The gastrocnemius muscle

This is the prominent muscle we see in the back part of the calf.

It is composed of two heads, crosses both the knee joint and the ankle joint, and participates in actions like walking, running, jumping, and rising on the toes.

The soleus muscle

Beneath the gastrocnemius is a deeper muscle called the soleus.

It is not as prominent to the eye, but it has a very important role.

The soleus acts mainly at the ankle joint and participates in maintaining body stability in standing and walking.

It is relatively rich in muscle fibers adapted to prolonged activity, so it can work over time and help maintain posture.

Both muscles work together and connect through the Achilles tendon to the heel bone.

But each of them has different characteristics, so it is worth combining exercises activating both.

How do the calf muscles assist blood circulation?

Imagine you are standing in place for a prolonged time.

Gravity affects the blood pressure inside the leg veins, especially in the lower areas.

When we begin to walk, the calf muscles contract and release alternately.

These contractions help empty some of the blood from the deep veins and transfer it upward.

While the muscles relax, the veins can fill with blood again.

Thus a cyclic pumping action is created.

The more we move the ankles and activate the calf muscles, the more we assist the natural mechanism of venous blood return.

This is one of the reasons walking and movement during the day are so important, especially for women spending many hours sitting or standing for prolonged periods.

What happens when we sit for hours?

When we sit in front of the computer, watch television, or are on a long flight, the calf muscles do not act at the same frequency as during walking.

As a result, the calf muscle pump operates less.

In some people this may contribute to a feeling of heaviness in the legs or slight swelling in the ankles, especially at the end of the day.

Prolonged standing without movement can also cause similar feelings.

But it is important to me to emphasize that not all leg swelling stems from lack of movement.

Swelling can also be connected to venous insufficiency, medications, heart or kidney diseases, lymphatic problems, and additional medical conditions.

Therefore physical activity can support blood circulation, but it is not a substitute for medical evaluation when there are persistent symptoms.

Can weak calf muscles affect the veins?

The functioning of the calf muscle pump has importance in the venous system.

When the pump does not operate efficiently, it may contribute to difficulty in returning blood from the legs, especially in people already suffering from venous problems.

But it is important to understand that the situation does not depend only on muscle strength.

The integrity of the valves in the veins, ankle mobility, blood vessel structure, and various medical conditions also affect blood flow.

Therefore strengthening the calf muscles can be part of a lifestyle supporting leg function, but it does not guarantee prevention of varicose veins or treatment of venous insufficiency.

And what is the connection between the soleus muscle and blood sugar levels?

Here we arrive at one of the most interesting subjects in research on the calf muscles.

Muscles are not responsible only for movement.

They are also metabolically active tissues, using glucose and fats to produce energy.

The soleus muscle is especially interesting because it is adapted to prolonged activity and can use different energy sources over time.

In a small study published in 2022 in the journal iScience, researchers from the University of Houston examined a unique movement called the Soleus Push-Up.

The participants performed repeated movements of lifting the heel while seated, in a manner intended to activate the soleus muscle.

The researchers found that under the experiment conditions, the activity affected metabolic measures and the glucose response after consuming a glucose-containing drink.

These are interesting findings, because they suggest that even activation of a relatively small muscle group can affect metabolic processes under certain conditions.

But there is an important point here.

The study did not prove that every regular heel raise while seated will cause the same effect on blood sugar levels.

The movement studied was controlled and precise, and research in the field is still limited.

Therefore it is not correct to present the exercise as a proven treatment for diabetes or as a substitute for walking and physical activity.

And nevertheless, it reminds us that even small movement can be preferable to prolonged sitting without movement.

Can the soleus muscle be activated while seated too?

Definitely.

A simple movement of lifting the heels can be performed also when we sit on a chair.

Place the feet on the floor, lift the heels, and leave the front of the foot in contact with the floor.

Afterward lower the heels and repeat the action.

The movement activates the muscles responsible for pointing the foot downward, including the soleus.

When the knee is bent, the relative contribution of the soleus to the movement increases compared to the gastrocnemius.

This can be a convenient way to integrate a little movement during computer work or prolonged sitting.

But it is important to remember this is not exactly the same action examined in the research protocol, and there is no guarantee it will bring the same metabolic results.

How do we strengthen the calf muscles?

The good news is that no special equipment or gym is required to start.

A few simple exercises can be integrated during the week.

1. Standing heel raises

For strengthening the calf muscles, with emphasis on the gastrocnemius and soleus.

Stand upright next to a chair or wall you can use for balance.

Lift the heels slowly until you are standing on the balls of the feet.

Hold for a moment and lower the heels in a controlled manner.

You can start with two sets of 10–15 repetitions, according to personal ability.

As the exercise becomes easier, you can add repetitions, resistance, or gradually progress to performing it on one leg.

2. Seated heel raises

An exercise emphasizing the work of the soleus.

Sit on a chair with the knees bent and the feet placed on the floor.

Lift the heels while leaving the front of the foot on the floor.

Lower slowly and repeat the movement.

You can perform 15–20 repetitions at a comfortable pace.

To strengthen the muscle significantly over time, it may be necessary to gradually add resistance, for example using a dedicated machine at the gym.

But even without weight, the movement can be a simple way to activate the legs while seated.

3. Daily walking

Walking is one of the most natural ways to activate the calf muscle pump.

With every step, movement occurs at the ankle and the muscles contract and release.

Walking also activates additional muscle groups and contributes to cardiovascular health, endurance, and physical fitness.

If you sit many hours during the day, try to integrate short walking breaks.

Even a few minutes of movement can help break a prolonged sequence of sitting.

4. Climbing stairs

Climbing stairs activates the leg muscles, including the calf muscles.

It can also raise the heart rate and contribute to aerobic fitness.

Stairs can be integrated as part of daily activity, according to ability and health condition.

5. Ankle movements during prolonged sitting

During a flight or long trip, you can move the feet up and down.

This movement is sometimes called Ankle Pumps.

It activates the muscles around the ankle and encourages the action of the venous pump.

It is also recommended to get up and walk from time to time when this is possible and safe.

On long flights, people at increased risk of blood clots may need additional medical recommendations, and ankle movements alone should not be relied upon.

Is it also important to stretch the calf muscles?

Yes, especially if there is stiffness or limitation in the ankle range of motion.

The calf muscles and Achilles tendon participate in many movements, and suitable flexibility can contribute to movement comfort.

A gentle stretch can be performed standing in front of a wall, with one leg behind and its heel remaining on the floor.

When the back knee is straight, the stretch emphasizes the gastrocnemius muscle more.

When the knee is bent slightly, a stretch can be felt in the soleus area.

It is important to perform stretches without sharp pain and without bouncing.

If there is an Achilles tendon injury, heel pain, or an orthopedic problem, it is worth receiving suitable guidance before performing exercises.

Can strengthening the calf muscles reduce leg swelling?

When slight swelling is connected to prolonged standing or sitting, movement and activation of the calf muscles may assist venous blood return and ease the feeling of heaviness.

But the result depends on the cause of the swelling.

For example, swelling stemming from venous insufficiency is not identical to swelling stemming from lymphedema.

The lymphatic system and the venous system work together to maintain fluid balance in the tissues, and muscle movement can assist the fluid flow processes.

Nevertheless, calf exercises alone do not correct damage to the lymphatic system or another medical problem.

If the swelling returns frequently, it is worth clarifying the cause and not assuming it is only a matter of inactivity.

Is there a connection between the calf muscles and cellulite?

This is a question arising quite a lot when talking about the appearance of the legs.

Cellulite is connected to the structure of subcutaneous fat tissue, connective tissues, genetics, and hormonal influences.

Strengthening the leg muscles can improve strength and the muscular appearance, and sometimes affect the general appearance of the leg.

But there is no proof that strengthening the calf muscles eliminates cellulite or directly changes the structure of the connective tissues responsible for its appearance.

Here too it is worth distinguishing between improving fitness and strength and promises of an aesthetic change that is not guaranteed.

Is standing on the toes enough to improve blood circulation?

The movement definitely activates the calf muscle pump.

But our blood system is much more complex.

Blood vessel health also depends on heart function, the condition of the arteries and veins, general physical activity, smoking, blood pressure, sugar levels, and additional factors.

Therefore heel raises are a useful exercise, but they are not a substitute for aerobic activity and muscle strengthening of the whole body.

I love thinking of them as a simple addition that can be easily integrated into the daily routine.

When do swelling or pain in the legs require medical examination?

It is important to me to add this point too.

If you suffer from sudden swelling in one leg, especially when accompanied by pain, local heat, or redness, urgent medical examination should be sought.

Such symptoms can sometimes indicate a blood clot in a deep vein.

If sudden shortness of breath, chest pain, or fainting also appear, immediate urgent medical help should be sought.

Persistent swelling in both legs, skin changes, or recurring pains also justify evaluation.

Exercises are an excellent tool for maintaining muscle function, but they do not replace medical diagnosis.

Our approach at OrOrgani

At OrOrgani we talk a lot about the connection between external care and habits supporting body health.

I believe self-care is not summed up only by what we apply to the skin.

It also includes movement, sleep, nutrition, drinking, and listening to the body.

The calf muscles are a wonderful example of a system working for us every day, without us dedicating almost any thought to it.

We use them in every walk, every stair climb, and every time we stand on our toes.

And sometimes it is enough to understand their role to receive motivation to move a little more.

There is no need to start with a complex workout.

You can start with a few heel raises next to the kitchen counter, a short walk between tasks, or a movement break in the middle of a workday.

In summary: Our second heart needs movement

The heart is the central pump of the blood system, but the calf muscles fulfill an important role in returning venous blood from the legs.

Every time we walk or activate the ankles, these muscles help push the blood upward.

When we sit or stand without movement for hours, the activity of the pump decreases.

Therefore walking, movement breaks, and strengthening the calf muscles are simple habits that can contribute to leg function and physical fitness.

The research on the soleus muscle and metabolism adds another reason to take interest in this muscle, even if additional studies are still required to understand the practical significance of the findings.

I think the most beautiful thing about our body is discovering how many smart systems operate in it without us noticing.

Our calf muscles are not only muscles shaping the appearance of the legs.

They are part of a mechanism helping us stand, walk, and return the blood to the heart.

So next time you stand in the kitchen, wait for coffee, or sit in front of the computer, try moving the ankles a little or lifting the heels.

This is a small movement reminding us how much our body needs movement throughout the day.

With love,
Nurit
OrOrgani

With love,
Nurit Rozenblat
OrOrgani

FOLLOW ORORGANI    Website · Blog · YouTube · Instagram · Facebook · Threads · Medium · Substack