Studies show that exercise could help regenerate your heart and make it stronger.
Most everyone knows that exercise delivers huge benefits to
the body's metabolism and cardiovascular system. But what scientists understand less is how physical activity influences the
heart itself. Sure,
aerobic exercise makes your heart more efficient and stronger -- but does exercise actually change your heart physically?
New studies in the journal "Cell" show that exercise triggers a genetic program that causes the heart to grow. Its muscle cells
start to divide. This change is driven by a gene that controls
other genes. Known as "C/EBPb," the gene was already found to
play important roles in other parts of the body. But this is the first look at how it might influence the heart.
Essentially, this genetic pathway shows that physical activity leads to a good kind of heart growth. It is yet another reason to keep on exercising, the researchers state. What's important from a treatment standpoint is that this finding could open up new therapeutic possibilities for people unable to exercise.
We already knew that the heart adapts to increased pressure and volume by increasing in size. That's the same if it's something good (e.g. exercise) or something bad (e.g. high blood pressure).
When it's a disease, those changes can ultimately lead to heart failure and arrhythmias.
In the new study, the researchers sought to better understand those differences between good and bad. They did so in mice; both mice that exercised and those that had their aortas surgically constricted (which causes the heart to increase in size).
They found changes in 175 genetic factors in exercised mice and 96 in mice whose aortas were constricted. Importantly, the
changes showed little overlap. For instance, 13% of the genes triggered by exercise help cells divide, compared to less than
one percent of the genes that changed with surgery.
That's when they found C/EBPb, which decreases about two-fold with exercise, and another that rises instead. Studies have
shown that the decline in C/EPBb leads to changes that appear the same as those that happen as you exercise (meaning good changes). These changes include greater heart muscle size and greater proliferation of heart cells.
Mice with those lower C/EPBb levels also were resistant to heart failure. This finding is important, as there is little prior evidence
that shows increasing in heart size with exercise has direct benefits.
What it also shows is that the heart could potentially regenerate its muscle. And we can help do it: by getting some exercise.
