RELATED: Drinking This Daily Can Slash Your Risk of Heart Failure, New Study Says. Experts warn that there’s one feeling in your legs you should never ignore when it comes to your heart health. “People with heart failure often have weakness in their leg muscles,” says a 2013 study conducted by UCLA researchers in collaboration with the National Heart, Lung, and Blood Institute (NHLBI). A separate 2009 study published by the American Heart Association in the journal Circulation: Heart Failure notes that “patients with chronic heart failure (HF) frequently experience skeletal muscle weakness that limits physical function. The mechanisms underlying muscle weakness, however, have not been clearly defined,” the researchers wrote. RELATED: Not Doing This Before Bed Could Be Hurting Your Heart, Experts Warn. The Circulation study tested the hypothesis that heart failure leads to leg weakness by changing the “quantity and functionality of the myosin molecule,” a protein that converts chemical energy into mechanical energy, resulting in musculoskeletal movement. Loss of this protein ultimately leads to “muscle weakness and exercise limitation in patients” with heart failure, the study authors believe. The UCLA researchers add that abnormal activation of the sympathetic nervous system (SNS) is known to occur in people with heart failure, and suggest that this could also contribute to muscle weakness in heart failure patients. Further research is needed to fully understand why those with heart failure often experience weakness in the legs. Those suffering from heart failure are often advised to lose weight as a means of slowing their condition’s progression, notes the UCLA study. “However, many people with heart failure develop weakness in their leg muscles, which can make exercise difficult,” the study authors explain. In some patients, this can create a cycle of weight gain and progressively worsening heart symptoms.ae0fcc31ae342fd3a1346ebb1f342fcb The good news? The Cleveland Clinic has exercise guidelines specifically designed for those with heart failure. They advise starting slowly and gradually increasing your total length of exercise, working out in five to ten minute increments, and trying certain aerobic exercises which take pressure off your legs, among other things. For more health news sent directly to your inbox, sign up for our daily newsletter.  According to the Mayo Clinic, there are several signs of heart failure besides leg weakness that are important to be aware of. These include shortness of breath during exercise or when lying down, fatigue, swelling in the lower extremities, persistent cough or wheezing, swelling of the abdomen, weight gain, nausea, and lack of appetite. Signs that your heart failure has become an emergency include chest pain, fainting or severe weakness, rapid or irregular heartbeat, severe shortness of breath, or a persistent cough which produces pink foam or mucus. Speak with your doctor if you notice symptoms of heart failure, and call 911 if you experience emergency symptoms of the condition. RELATED: If You Feel This in Your Feet, Your Heart Attack Risk Skyrockets.