The heart is amazing! Your heart does more work than any other muscle. And the race isn't even close. Your heart works continuously over your entire lifetime without ever stopping to keep blood circulating. Did you know that a 150-pound adult has about 5.5 litres of blood on average, which the heart circulates about three times every minute?
This means that in an average lifetime, the human heart beats more than 2.5 billion times.
Scientific studies have consistently found a strong relationship between physical activity and a healthy heart. Clinical trials have also shed light on the precise reasons exercise strengthens the heart:
- It enhances the cardiorespiratory system.
- It increases HDL cholesterol.
- It lowers triglycerides, a type of fat that circulates in the blood.
- It reduces blood pressure and heart rate.
- It lowers inflammation and improves blood sugar control.
- It increases insulin sensitivity.
With a long list of benefits for the heart, what sort of exercise should we be doing, and how often?
1. Cardio Training
Cardiovascular exercise involves the use of large muscles in a repetitive manner, activating muscle fibres programmed for endurance and utilising a heart rate range anywhere from 40 to 85 percent of your maximum heart rate. This maximum rate can be calculated based on the person's age. An estimate of a person's maximum age-related heart rate can be worked out by subtracting the person's age from 220. For example, for a 50-year-old person, the estimated maximum age-related heart rate would be calculated as 220 - 50 years = 170 beats per minute (bpm).
So how much exercise should we be doing? An average person should aim for:
· 150 minutes of moderate-intensity aerobic exercise a week.
· 2 sessions of about 30 minutes each of resistance training a week.
You can spread the aerobic activity throughout the week however you like, such as 30 minutes five days a week, or 50 minutes three days a week. Examples include running, swimming, brisk walking, riding a bike or playing tennis.
If you're ready for more intense workout sessions, you should aim for:
- 75 minutes of vigorous aerobic exercise a week.
- 2 sessions of at least 30 minutes each of resistance training a week.
Vigorous exercise should get your heart rate up to 70 to 85 percent of your maximum heart rate.
How does it work?
When performing cardio based exercises, blood flow is directed toward working hard-working muscles and away from areas that aren't doing as much. Therefore, there is increased blood flow and blood volume returning to the heart. As the heart registers a larger blood volume, over time the left ventricle adapts and enlarges. This larger cavity can hold more blood and also ejects more blood per beat, even at rest.
With consistent cardio training over time, our resting heart rate drops because each beat delivers a bigger burst of blood, and fewer beats are needed. Exercise also stimulates the production of new blood vessels. As we make more blood vessels, there are more places for blood to flow, which results in more efficient circulation. Cardiovascular exercise increases the number of new blood vessels. This all works to take pressure off your heart and is why cardio exercise is recommended for optimum heart health.
2. Strength Training
For strength-building activities, ideally, you should set aside at least two days a week for 30 minutes of exercise that works the major muscle groups - such as the legs, back, shoulders and arms. But what counts as strength training? This might be exercises such as lifting weights, using resistance bands, doing bodyweight exercises like yoga or callisthenic training.
Strength training exercise works the heart in a completely different way to cardio. At any given moment, certain muscles are contracting. As the muscles contract – for example the arm muscles during a bicep curl - they press and close the blood vessels that flow through them. This leads to increased blood pressure in the rest of the body and the heart has to force to push blood out.
The heart adapts to this by increasing the thickness of the left ventricle wall. This thickness derived from regular weight training is healthy, whereas the thickness gained from chronic high blood pressure is not. Resistance training also increases the size of your blood vessels and the healthy heart becomes stronger with a lower resting heart rate.
Exercise will go a long way to having a positive impact on your heart. With a smart, well-designed exercise programme, alongside practicing healthy eating and stress-reduction techniques, you can ensure that you keep your heart is in optimum condition.