Exercise for heart health

You probably hear all the time that exercise is good for your heart health, but what does that mean?   In a past blog I highlighted how your fitness level seems to be more strongly connected to your risk of heart disease than your weight. Let’s take a closer look at how exercise helps to prevent heart disease.    There are many types of heart disease.  Here we will talk specifically about exercise for preventing coronary artery disease, the kind that can lead to a heart attack.

What leads to a heart attack?  A heart attack (or MI – myocardial infarction) is when one of the arteries of the heart is blocked. Since the job of arteries in the heart is to deliver oxygen and other nutrients to the different parts of the heart muscle, blockage means that part heart muscle is damaged from lack of oxygen.

There are many reasons why a blockage can occur.  Generally it is the gradual accumulation of fats, sugars and on the walls of arteries.  The risk factors for heart disease increase the chances of these deposits forming:

• High blood pressure:  Normally the inside lining of arteries is smooth.  But high blood pressure over time wears down the walls of arteries so substances like fat and sugar in the blood are more likely to stick to the walls building up and leading to a blockage
• Diabetes: The higher amount of sugar that stays in the blood with diabetes means there is more substances to stick to the walls of the arteries
• High cholesterol:  The higher the amount of fats floating in blood, the more chance it has to stick to the walls of arteries
• Smoking: Smoking increases the risk of  blood clots which can block an artery in the heart (or anywhere in the body).   Smoking also doubles the level of risk of developing other risk factors for heart disease.
• Stress:  When your body is in a stress response, it increases the amount of fats and sugars in your blood, constricts your blood vessels, and increases clotting in your blood (in case you are injured).  All of these increase the chance that your arteries become damaged and blocked.

When you exercise, several things happen right away that directly improve these conditions and thus helping to prevent a blockage in your arteries.

• Your body releases nitric oxide, a natural blood vessel relaxer.  This counteracts the effects of high blood pressure and stress to reduce the chances of damage to the walls of your arteries from these conditions. Nitric oxide remains in your system for up to 22 hours after one 30 moderate intensity bout of exercise.
• Your body uses fats and sugars in your blood to fuel moving muscles.  This way they are not hanging around in your arteries ready to attach to the walls and create a blockage. Depending on the type and intensity of exercise, this higher usage of fats and sugars in the blood can last up to 72 hours after one single exercise bout.
• Your body shifts to a relaxation response IF exercise is not stressful.  Since stress prepares your body for movement, exercise that is not stress producing gives your body what it has prepared for in the stress response, allowing your nervous system to shift back to the job of healing and repair.
• Brain chemicals for a calmer body.  When you exercise your brain releases chemicals that help you stay calm, think clearer, and focus better for hours after. It also lowers chemicals that increase inflammation (like cortisol) that can exacerbate a blockage.    Even just ten minutes has been shown to release these chemicals.   Improved brain function means a better mood and less stress.

Over time with consistent exercise, your body changes in ways that help to give it even further protection from heart disease.

• New blood vessels grow in your heart to provide more blood flow to the heart muscle.  This is called collateral circulation and provides protection if one artery is blocked, these smaller vessels can get blood to that area of the heart, reducing or preventing the damage of a blockage.
• Muscles become more efficient so every day activities are less strain on your heart.  When you improve your stamina and strength, your heart does not have to work as hard for everyday activities.  Less strain means less demand of oxygen with physical activities, making your heart handle daily activities and stress better.
• Your heart becomes a more efficient pump.  Your hearts job is to pump blood to the rest of the body.  As you improve your fitness level, your body does not need to beat as fast, because it pumps more blood with every beat.   A stronger pump means it does not need to work as hart do to its job.
• Better management of other risk factors.   When you exercise regularly, all of the other risk factors that contribute to blockages in your heart improve.  Regular exercise is the all in one treatment for lowering your risk of heart disease.

Exercise directly and indirectly reduces the root causes of heart disease.  Even if you already have heart disease, exercise has been shown to reduce the risk of a second heart event.   There is no other treatment available that does all of this at once.  Exercise truly is medicine!

Keep Moving, Be Well,

Janet