The Calf Muscle: An Overlooked Key to Longevity and Heart Health
While organs like the heart, brain, liver, and lungs are widely recognized as essential for survival and a healthy life, experts are now highlighting an unlikely muscle that could be pivotal in understanding longevity: the calf muscle. Located on the back of the lower leg, stretching from below the knee to above the heel, this muscle is crucial for mobility and stability, aiding in pointing the toes and propelling the body during walking and running.
The Calf as the Body's 'Second Heart'
Recent studies suggest that neglecting the calf muscle may increase the risk of heart-related issues, such as blood clots. When the heart pumps, it distributes oxygen-rich blood throughout the body, including the legs. However, returning blood from the legs back to the heart requires additional effort beyond a single pump, necessitating a boost. The calf muscle plays a vital role in this process by compressing deep veins during movement, which helps push blood upward against gravity toward the heart. This mechanism is critical for preventing blood clots and reducing strain on the heart, earning the calf the nickname 'the body's second heart.'
Calf Size and Its Link to Lifespan
Beyond its functional importance, the size of the calves serves more than just aesthetic purposes. A more muscular calf is a strong indicator of physical performance and helps prevent muscle decline, known as sarcopenia. Affecting 10 to 16 percent of the elderly globally, sarcopenia is associated with a significantly higher risk of death, with some studies estimating over a 300 percent increased risk. Experts believe that the calf muscle's size may even predict lifespan.
A recent study involving 63,000 adults found that for every 1cm (0.4 inches) increase in calf circumference, the risk of death decreased by five percent. In another study led by researchers at the Catholic University of Sacred Heart in Italy, scientists discovered that calf circumference was directly linked to strength elsewhere in the body. They evaluated individuals aged 80 and older, finding that physical performance and muscle strength 'significantly improved' as calf circumference increased. Additionally, frailty scores were lower among those with larger calves, supporting the idea that calf size can indicate muscle mass, strength, and overall fitness.
Preventing Blood Clots and Promoting Health
Caring for this 'second heart' mirrors caring for the actual heart—through movement. The Physical Activity Guidelines for Americans recommend at least 150 minutes of moderate exercise or 75 minutes of vigorous exercise weekly, along with muscle-strengthening workouts at least twice per week. Activities like running, walking, jumping rope, and seated or standing calf raises can strengthen the calves and promote regular movement.
When the calf muscle moves, it opens one-way valves in leg veins to push blood to the heart; relaxing it closes these valves. Prolonged sitting or standing can cause pressure buildup in veins, damaging valves over time and leading to blood pooling in the legs. This sluggish blood allows cells to stick together, forming clots in deep veins, a condition known as deep vein thrombosis (DVT).
DVT affects up to 900,000 Americans annually and can result in blood clots breaking loose and traveling to the lungs, blocking blood flow—a condition called pulmonary embolism. This can cause permanent organ damage, and about one in three people with an undiagnosed and untreated pulmonary embolism die. The CDC estimates that 100,000 to 200,000 Americans die from pulmonary embolism each year.
Practical Steps for Calf Health
In addition to exercise, compression socks can help prevent circulation issues in the legs linked to DVT and pulmonary embolism. By incorporating calf-strengthening activities into daily routines, individuals can support heart health, reduce the risk of blood clots, and potentially enhance longevity through improved muscle mass and function.
