You can only be sure that the intensity is
enough to improve your cardiorespiratory fitness
level by keeping track of your heart rate during a workout.
Workout strength is the most important factor for maximizing cardiorespiratory fitness (cardio or CR).
Changes in CR fitness are directly related to how an aerobic exercise is “hard” to perform. The more energy that is spent per unit of time, the greater the exercise intensity,
the greater the effect on cardiorespiratory fitness.
You have to know how hard it is to decide if an aerobic
exercise like running creates an impact of CR training,
or if it just burns a few calories. At function or workout, the heart rate is an excellent indicator of how much energy you expend. You can only be sure that the intensity is enough to improve your CR fitness level by keeping track of your heart rate during a workout. In other words, your ability to monitor your heart rate is the most significant single key to success in CR training.
Training Heart Rate (THR)= Desired Workout Intensity THR is the heart rate you need to exercise to get an effect on training. The fitness gurus of the U.S. Army has given us two methods of determining the THR.
The first method is simpler to use, percent maximum heart rate (percent MHR), while the second method is more accurate, percent reserve heart rate (percent HRR).
With this process, the approximate average heart rate is used to calculate the THR. By subtracting your age from 220, you can estimate your maximum heart rate (MHR) A 20-year-old would thus have an estimated peak heart rate (MHR) of 200 beats per minute (220-20= 200).
A person in poor shape should exercise at 70% of his / her MHR; if he/she is in relatively good shape, at 80% MHR; and if he/she is in excellent shape, at 90% MHR.
A 20-year-old would have a THR of 160 beats per minute (BPM) in good physical condition. 220-20= 200*.80= BPM 160.
A 30 year old would have a THR of 152 beats per minute (BPM) in good physical condition. 220-30= 190*.80= BPM 152.
A 40-year-old in poor physical condition would get 126 beats per minute (BPM) of THR. 220-40= 180*.70= BPM 126.
The percent HRR method is a more accurate way to calculate THR.
The 60 to 90 percent HRR range is the THR range where people can exercise to boost their CR fitness levels. If you are aware of your general CR fitness level, you can determine which percentage of HRR is a good starting point for you. For example, a person in excellent physical condition may start at 85% of his / her HRR; if he/she is in reasonably good shape, at 70% HRR; and if he/she is in poor shape, at 60% HRR.
To reach or sustain an acceptable level of fitness, most CR workouts should be performed with the heart rate about 70 to 75 percent HRR. A person who has attained a high fitness level may derive more gain from working at a higher percentage of HRR, particularly if he is unable to find more than 20 minutes for CR exercise.
Exercising at any lower percentage of HRR than 60 does not provide a proper stimulus for training in the heart, muscles and lungs. It can be dangerous to exercise at over 90 per cent. Before anyone starts aerobic training, he should be aware of his THR (the heart rate at which he needs to exercise to get an effect of training).
The following example shows how to calculate the THR by using the resting heart rate (RHR) and age to measure reserve heart rate (HRR). The example is a 20 year old with a fairly good physical shape.
STEP 1: Subtract your age from 220 to assess MHR. E.g. MHR = 220 -20.
STEP 2: Determine resting heart rate (RHR) by measuring the resting pulse for 30 seconds in beats per minute (BPM), and subtract the count by two.
It can be used for a shorter period but a count of 30 seconds is more accurate. This count should be taken while you are full of relaxation and rest. We use a RHR of 69 BPM for this example.
STEP 3: Determine reserve heart rate (HRR) by subtracting the RHR from the MHR estimate. E.g. HRR= 200-69= BPM131
STEP 4: Calculate THR by (1) multiplying HRR as a percentage by the relative fitness level, and (2) adding the result to HRR. For example, at 70 per cent HRR, our 20-year-old in good physical condition will exercise.
(1) .70 * 131 = 91.7
(2) 91.7 + 69 = 160.7
In summary, a reasonably fit 20-year-old with a resting heart rate (RHR) of 69 BPM has a goal of 161 BPM for training heart rate (THR).
The body will normally have reached a “Stabley State” after five minutes of exercise during aerobic exercise and the heart rate will have leveled off.
At this time and immediately after exercise, your heart rate should be monitored to see if you are within your desired range of THR.
If your pulse rate is below the THR, you have to exercise more difficultly to increase your pulse to the THR. If your pulse is above the THR, the amplitude should be reduced to the THR target to reduce the pulse rate.