February is the month we usually associate with Valentine’s Day and so hearts are on our minds. We see cardboard hearts displayed in store windows, chocolate and cinnamon hearts in candy stores, and Valentine cards sent to and from kids in school. But have you given much thought to the other heart we associate with February? February is Heart Month!
Heart and Stroke foundations throughout the world recognize February as Heart month and take the opportunity to draw special awareness to the heart that isn’t cardboard, cinnamon, or chocolate. The one that is in your body, pumping blood to keep you alive.
Take care of the most important muscle.
The heart is a muscle and like any other muscle, it needs to be strong. Unlike the muscles that attach to our joints and make us move, the heart needs a unique type of physical activity or exercise regimen. We call this cardio activity because it refers to the cardiovascular or circulatory system. It is also known as aerobic activity because it requires the presence of oxygen. By doing cardio or aerobic activity, we make our heart work more efficiently in the transport of oxygen to our entire body. To get the most oxygen circulating through the system, the heart needs to pump harder and faster, which will make it stronger. The activity must involve large muscular movement so that more blood is needed for those working muscles. It needs to be continuous, ideally for 10 minutes or more at a time and it should be done most days of the week.
Before I tell you more about the things you can do to make your heart stronger, let’s first review some concepts regarding the cardiovascular system.
The cardiovascular system is comprised of the heart (pump) and arteries and veins (the vessels or carriers) which deliver blood with oxygen from the lungs and other nutrients to all the cells of the body. When the heart pumps, there is a detectable rhythm or pulse and this can be measured as a heart rate. Under normal healthy conditions, the heart at rest pumps blood more slowly than during physical activity. There is a wide range of heart rates considered to be normal. Heart rates are normally measured in beats per minute (BPM). Healthy resting heart rates are between 60 and 80 BPM, normally around 70 for males, 75 for females. Each time the heart contracts, blood circulates through the body, being forced through the arteries. This force is known as blood pressure. Normal resting blood pressure is around 120/80 (measured in millimetres of mercury or mm/Hg). The first number represents the pressure when the heart contracts (systolic blood pressure). The second number represents the pressure when the heart relaxes (diastolic blood pressure). During physical activity, as demand for oxygen increases, the heart has to pump faster to provide more oxygen. The amount of blood the heart pumps out in one beat is called the Stroke Volume. The amount of blood the heart pumps out in one minute is called Cardiac Output.
Another important concept in understanding the mechanics of the heart and circulatory system is Aerobic Capacity. This is the body’s ability to deliver and use oxygen at the cellular level. Aerobic Capacity is often referred to as VO2 max.
The ageing heart
As we age, a number of physiological and anatomical changes occur:
- The left ventricle of heart increases in wall thickness, which means it can’t pump out oxygen-rich blood to the aorta as efficiently as before.
- The aorta and arteries become thicker and less pliable, which means they can’t deliver this blood to the other parts of the body as efficiently as before.As a result:
- Stroke Volume decreases
- Blood Flow decreases
- Blood Pressure increases in the systolic (contraction) phase
- During physical activity, it takes the entire cardiovascular system longer to adapt to increased demands.
- The heart takes longer to return to its resting heart rate after exercise.
- The efficiency of oxygen exchange declines by about 1% per year due to decreases in maximum heart rate, total body muscle mass, and the ability of muscles to use available oxygen. The most drastic declines are between ages 65 and 75 and between 75 and 85.
Despite changes, heart function in non-diseased individuals remains adequate for resting and light physical activity. However inactivity, smoking, diabetes, and poor eating habits all contribute to an unhealthy heart and increase the risk for heart disease, stroke, and heart attack.
How exercise helps the ageing heart
As we do more physical activity and exercise, our whole body including our heart gets fitter. Our resting heart rate decreases because the heart becomes stronger, and thus contracts with more force, so not as many beats are necessary to pump the required amount of blood. Also as we get fitter, our resting blood pressure stays pretty constant because exercise helps to maintain the elasticity of the vessels and keeps the circulatory system healthy. So, one might argue that exercise helps combat the effects of ageing and certainly helps reduce the effects of premature ageing resulting from unhealthy lifestyles.
So, what can you do for your heart?
Health Canada recommends 30-60 minutes of physical activity a day. If you have not been active for quite some time, start with 10 minutes of activity a day and then build up. If you are so crunched for time that you can’t be active for 30-60 minutes at a time, then do 10 minutes of moderate level activity at intervals throughout the day. Suggestions for activities are:
- Brisk walking
- Raking leaves
- Water aerobics
- Seniors fitness classes
Moderate activities are what is mostly recommended for older adults.
Younger or fitter adults may want to do more vigorous activity throughout the week and won’t need as much time in the activity because the effort is greater. Such activities for younger adults include:
- Fast swimming
- Fast Dancing
If you aren’t able to maintain at least a moderate pace of exercise, 60 minutes of lighter intensity exercise, activities, and sports are suggested during your day. For example:
- Light walking
- Easy gardening
- Tai Chi
The Heart and Stroke Foundation has a whole host of resources to help you. Please see their website for further details. Especially relevant and current this month is their 2010 Annual Report on Canadians Health, called A Perfect Storm, which was released at the end of January. Between 1994 and 2005, rates of high blood pressure among Canadians young and old skyrocketed by 77%, diabetes by 45% and obesity by 18% – which are all major risk factors for heart disease.
Recommendations from the Heart Association include better diet, quitting smoking, limiting alcohol intake, and of course, increasing the amount of physical activity. For those who already have heart disease and other conditions, they suggest the HeartWalk Workout.
As with any type of exercise, please consult your health care provider before beginning a program. Start slowly and build up!
So, now that it’s February, maybe it’s time to think not only about chocolate, cinnamon, and valentine card hearts but the heart beating inside you. Make this your month to give yourself a valentine’s day present — a more healthy heart!
To your health,
More information on becoming more active can be found in Canada’s Physical Activity Guide for Older Adults.
More information on prevention and treatment of heart disease can be found in Heart and Stroke Foundation of Ontario.