Posted on 8 March 2012 - 03:26pm
THE HEART is a myogenic muscular organ that pumps blood to the body by repeated, rhythmic contractions. Being a muscled organ, it is the hardest working muscle in the human body.  |
| Your workout will be all the more effective if you can get your heart pumping at maximum. SOURCES |
The heart, when in consistent working capacity, ensures optimal working condition of the brain. Any sudden disruption or irregularity (arrhythmia) in heart beat can be fatal.
Just like all the other organs in the body, the heart, too, is prone to degenerative diseases that can lead to failure over time.
One way of keeping the heart in tip-top condition is by exercising.
The maximum heart rate (HRmax) is the highest heart rate an individual can safely achieve through exercise stress.
The most accurate way of measuring HRmax is via a cardiac stress test. When undertaking such a test, the subject exercises while being monitored by an EKG (electrocardiography).
During the test, the intensity of exercise is periodically increased. The subject continues exercising until certain changes in heart function are detected in the EKG, at which point, the subject is directed to stop.
Cardiac stress tests are hardly performed during general medical check-ups, unless a prevailing coronary artery disease (CAD) is evident or the person is showing signs of risk factors such as hypertension, high cholesterol or obesity.
Various formulas are used to estimate individual maximum heart rates based on age, but maximum heart rates vary significantly among individuals.
The most common formula to determine maximum heart rate, with no indication of standard deviation, is: HRmax = 220 - (age of subject).
Hence, a 30-year-old person’s maximum heart rate would be (220 -30) 190 beats per minute (b/min).
This formula though has recently been replaced or modified to include other variables for accuracy.
Unfortunately, the formula is not considered by reputable health and fitness professionals to be the best predictor of HRmax. Researches spanning two decades revealed that one variable error was not accounted for – gender.
Men, through their biological and physiological attributes, have a higher maximum heart rate by 7-11 b/min.
The updated formulas suggest that a woman’s maximum heart rate be calculated as 206 minus 88% of her age; for a man, it is 220 minus his age.
For example, a 50-year-old woman would have a maximum heart rate of 162; a similar-aged man would have 170.
Regardless of gender, power output and frequency decreases over time. Heart rate formulas are estimates that do not take into account people’s medical conditions and height, weight and blood volume specifics.
If you are taking any medication, always discuss your exercise plans with your physician. A number of medications can lower your maximum heart rate, including beta blockers, most antiarrhythmics (to address heart beat fluctuations), some calcium blockers and H2 blockers used to treat acid reflux.
It is also advisable to engage a personal trainer who can monitor your intensity and progress.
Once you get your maximum heart rate, calculate 50% to 85% of that number to find the intensity zones you want to hit as you exercise.
Staying within these zones is the best way to burn fat and calories, lower your cholesterol and blood pressure, and improve the health of your heart.
If you are beginning a cardio programme, aim to hit 50%. Move to a higher rate when your cardiovascular fitness improves.
Determining a proper target heart rate depends on the intensity level of your workout. The general range is 60% to 85% of your maximum heart rate, or MHR.
For light-intensity exercise for a warm-up session, your target heart rate should be 50% to 60% of your MHR. Moderate-intensity exercise should be 60% to 70% of your MHR, and vigorous exercise should be between 70% to 85%.
Know your maximum heart rate and then work to achieve certain exercise targets based on that information. It will help you track your progress as you get healthier. It will also keep you from getting burnt-out on your cardio exercise programme.
Therefore, if you are planning to lose weight, keeping your heart rate zones in the lower limits may not be effective.
But extreme intensities can be detrimental as it places a great deal of stress on your heart. Exercising should be fun, not stressful.
Let’s be fit!
http://www.thesundaily.my/news/316499
