The target heart rate is the heart rate that one should aim for during exercise to keep the heart healthy. The human heart, beats, approximately 70-80 times per minute, at rest. The number of times the heart beats every minute is called the heart rate. It is expressed as the number of “beats per minute”. Generally, the heart rate is slowest during deep sleep and the highest during strenuous exercise.
The Resting Heart Rate and Target Heart Rate during exercise:
The resting heart rate is the number of times the heart beats per minute when one is at complete rest. A good time to check the resting heart rate is first thing in the morning after a good night’s sleep, before getting out of bed to grab that first cuppa. Generally, the resting heart rate is between 60 and 100 beats per minute for adults.
The resting heart rate can be affected by factors like stress, anxiety, hormonal status, blood pressure medications, and generally how physically fit and (or) active you have been. A consultation with a heart specialist is essential before embarking on an exercise regime especially after heart surgery.
A well trained athlete may have a resting heart rate as low as 40 beats per minute. Generally, the lower the resting heart rate is, the better. Several studies have shown a link between a higher resting heart rate poor physical fitness, higher blood pressure and weight gain. Excessive use of caffeine, smoking, stress, and binge drinking are other common causes of a high resting heart rate.
To keep the heart in good nick it is important to coax it every day to beat at a higher rate for a length of time and then allow time for relaxation. Over a few months, the “fitness” of the heart can thus be increased substantially.
So How Fast a Target Heart Rate is Fast Enough?
The safe maximum rate at which the heart can safely be coaxed to beat at for a period of time is called the maximum safe heart rate. The maximum safe heart rate is age dependent. Younger people can safely allow their hearts to beat faster than older folk. The maximum safe heart rate is calculated by subtracting the age (in years) from 220.
The maximum safe heart rate for a 30 year old would be 190 beats per minute. The maximum safe heart rate for a 60 year old would be 160 beats per minute. The maximum safe heart rate is slightly higher in smaller people, which is why women have a slightly higher maximum heart rate than men of the same age. The “heart rate reserve” is the difference between the maximal safe heart rate and the resting heart rate. The higher this number is, the more healthy you are.
The Target Heart Rate to aim for:
The target heart rate is expressed as a percentage of the maximum safe heart rate. The target heart rate one should aim for during exercise is 85% of the maximum safe heart rate. This would be around 160 beats per minute for a 30 year old and around 135 beats a minute for a 60 year old.
If your heart rate is way below the target heart rate, your heart is not being pushed enough and its fitness may not improve with time. If the target heart rate is way above the target heart rate, you are pushing it too much and in that unsafe zone, the risks to your heart are higher.
It is risky to aim to achieve 85% of your maximum safe heart rate (ie the target heart rate) on day one of your exercise program. A good start would be to try and achieve 50% of the maximum safe heart rate first and then gradually build up to the target heart rate (ie 85% of the maximum safe heart rate).
Count the pulse rate:
The heart rate can be easily and reliably counted by feeling the pulse on the radial artery on the wrist at the base of the thumb. The radial
artery pulse is a measure of the number of times the radial artery expands and relaxes due to the cyclical pumping and relaxing actions of the heart.
To measure the pulse rate, place the tips of the index and middle fingers over the radial artery on the wrist at the base of the thumb and press lightly. Count the pulse for a full 60 seconds or at least 30 seconds and multiply it by two.
Generally, the pulse rate is an accurate indirect estimate of the heart rate. Every beat of the heart results in a “pulse”. One notable exception is atrial fibrillation wherein every heartbeat does not result in a “pulse” of the radial artery.
In atrial fibrillation, the safe maximum heart rate and the target heart rate calculation is more complex and is best left to your Physician / Cardiologist to do for you. Some blood pressure medications may also affect the heart rate and confound calculations of the target heart rate and the safe maximum heart rate.
The Intensity of Exercise:
The American Heart Association defines mild intensity exercise as that which increases the heart rate to 40-50% of the maximum safe heart rate. It defines moderate intensity exercise as an increase of the heart rate to 50-70% of the maximum safe heart rate and vigorous exercise as that which increases the heart rate to 70-85% (target heart rate) of the maximum safe heart rate. 150 minutes of moderate intensity exercise 5 days a week is enough to keep your heart in good shape. That’s about 30 minutes a day on all weekdays.
If you want to aggressive with exercise, then, just 75 minutes of high intensity exercise every week (that’s 15 minutes on all weekdays) is enough. A heart rate of 70% of the target heart rate also helps in fat burn and weight loss.
It has also been proven that short bursts (30-60 second bursts) of vigorous intensity exercise interspersed in a 30 minute workout has added cardio-protective benefits. This is called high intensity interval training(HIIT). High intensity interval training is a well known way to improve health, build lean muscle, burn fat, and increase endurance. A HIIT workout typically alternates between short work intervals (70 to 90 percent max heart rate) and rest periods (60 to 65 percent max heart rate).
Lastly “cardiac fitness” is only one component of overall physical fitness. The other components are:
Muscle strength
Muscle endurance
Body composition
Body flexibility
Body co-ordination
Body balance
But yes ………these are subjects of future articles …………… so watch this space.