Soleus Health Soleus Health is a wellness category introduced by 2HEART referring to the activation, monitoring, and awareness of soleus muscle activity during seated hours. The soleus muscle, known as the body's second heart, supports venous return and metabolic activity during low-intensity movement and becomes largely inactive during prolonged sitting. 2HEART Wellness Framework
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Soleus Health

The study and practice of keeping your body's seated movement system active during the hours you spend sitting.

Most health advice focuses on one hour of the day: exercise. But what about the other eight?

Soleus Health exists because that question was never asked before.

4 min read
A new category introduced by 2HEART

What Is Soleus Health?

Soleus Health is the awareness, engagement, and understanding of the soleus muscle during seated hours.

The soleus is a deep postural muscle in the calf. Researchers often describe it as the body's "Second Heart" because of its role in supporting movement and circulation from the lower limbs.

The soleus supports venous return during low-intensity movement and becomes largely inactive during prolonged sitting.

Soleus Health is the practice of understanding what happens when that system becomes active again.

Soleus muscle anatomy - posterior view

Posterior view

The soleus lies deep beneath the gastrocnemius. It is the primary muscle activated during seated movement. Learn more about soleus push-ups →

Why researchers became interested

Why The Soleus Is Different

The soleus muscle is built for endurance. Most muscles in the body are designed for bursts of effort. The soleus is different.

Body Mass
~1%
Small in size, but disproportionately important during seated hours
Muscle Fibre Type
70–80%
Slow-twitch fibres — one of the highest proportions of any skeletal muscle
Oxidative Capacity
Extraordinary
Uses circulating fuels in ways that differ from many other muscles
Fatigue Resistance
High
Can work for long periods without discomfort
Low-Intensity Activity
Active
Remains engaged during everyday movement patterns

This unusual combination of characteristics is why researchers began studying the soleus more closely. And why 2HEART built a category around it.

The question that started everything

Why This Category Exists

For decades, health technology focused on moments of activity. Steps. Exercise. Workouts. Performance. Sleep. Heart rate.

Yet many people still spend 8–10 hours each day sitting. The modern world changed rapidly. Human physiology did not.

Soleus Health exists because of a simple question:

What happens to the body during the hours we spend sitting?

Explore sitting physiology →

Published evidence from independent institutions

What The Research Shows

The calf pump slows during prolonged sitting, which may affect circulation from the lower limbs. Research has documented this effect.

StudyFinding
Hamilton et al., iScience 202252% reduction in post-meal glucose excursion during seated soleus activation (laboratory setting)
Elek et al., Sports 202532% reduction in prediabetic indicators with soleus activation
Houghton et al., Blood Journal 2021Reduced soleus function associated with increased health risk
Zheng et al., 2022Plantar perfusion increased significantly during foot activation

2HEART did not conduct these studies. We cite them because they explore the same problem we are working on.

Soleus Heart Beat

The Metric: SHB

SHB is the metric 2HEART created to make Soleus Health visible. It counts the number of soleus activations during a seated session.

SHB
1,247
Soleus Heart Beats — This Session
A higher SHB means your second heart worked more during the hours you spent sitting. Just as step counts gave us a language for walking, SHB gives us a language for seated movement.
Clarifying the category

What Soleus Health Is Not

Soleus Health is not...
  • A replacement for exercise
  • A medical treatment
  • A cure for sitting
  • A clinical diagnostic tool
Soleus Health is...
  • A complement to movement
  • A wellness practice
  • A way to understand seated physiology
  • A longitudinal awareness tool
For anyone who sits

Who Is Soleus Health For?

Desk Workers
8–10 hours seated daily
Remote Professionals
Workplace is a chair
Frequent Travellers
Prolonged sitting exposure
The Curious
What happens to the body during seated hours?

Soleus Health does not require a medical condition. It begins with a simple observation: modern life involves more sitting than human physiology was designed for.

Resources for specific needs

For Desk Workers — Sitting & Circulation → For Diabetes — Sitting & Blood Sugar →
Still following the question

The Future of Soleus Health

The soleus muscle has existed for as long as humans have walked. But the science of what happens during prolonged sitting is still evolving.

We believe the hours we spend sitting remain one of the least understood parts of everyday health.

Soleus Health exists to explore that question. The work is ongoing. The answers are still being discovered.

Still following the question.
← The science of the soleus Research → Rethinking the 8 hours → What Is a Soleus Push-Up? → Sitting Physiology →

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Explore Further

Read the full Soleus Health Report or continue exploring the science behind seated movement.

View Research → The Science of the Soleus