A bedridden state is considered as the primary cause of progressive weakening of the human heart muscle. When a person spends most of the time laying down in bed, their heart becomes incapable of pumping enough oxygen to the brain and eventually the person stops breathing and dies due to heart failure. The likeliness of the condition is confirmed by a recent study conducted on mice.

During the study (Experimental Model of HindLimb Suspension-Induced Skeletal Muscle Atrophy in Rodents: Techniques and Protocols, Gabriel Nasri Marzuca-Nassr et. al. 2019), the mice were prevented from using their hind limbs for 28 days. This development interfered with the normal functioning of mitochondria in their cells. This further resulted in oxygen levels dropping and preventing the subventricular zone of the brain to maintain normal nerve function and developing new nerves. 

Impact of sedentary lifestyle on heart

The study showed that preventing the mice from using their legs decreased the neural stem cells number by about 70 percent as compared to other mice who exercised normally.

This development explains how heart failure is eventually caused and how it is capable of killing humans. It also explains how nerve damage is linked with movement of muscles and how patients suffering from diseases such as multiple sclerosis and spinal muscular atrophy have a higher rate of death from heart failure.

There are several other studies that prove that regular physical activity is necessary for normal growth and development of nerves during the course of human lifetime. People who are restricted to a bed and astronauts who are stationed in space, lose nerves at an alarmingly high rate. When a person is not walking and not using the legs regularly, there is a drastic loss of muscles, heart muscles in particular. This is the primary cause of death from heart failure.

According to Dietitian Sai Mahima, high meat and sugary diets cause arteriosclerotic plaques in artery development in humans. This result is similar to a diet high in inflammatory foods. This development is the root cause of artery blockage and sudden death of heart muscle, which is commonly known as heart attack. 

Exercise and heart health

It is also found that even after having a healthy diet, lack of exercise weakens mitochondria, which decreases new nerve growth, that decreases heart muscle strength and size and can eventually weaken the heart so much that it does not have enough strength to circulate blood to the brain and throughout the body.

Thus, it is very important to maintain a balance between a healthy diet and regular physical exercise such as walking, jogging or running. A healthy heart program helps in maintaining muscle strength and prevention of heart failure.