HR = Heart Rate
Max HR = Maximum Heart Rate
HRmax = Maximum Heart Rate
HRrest = Resting Heart Rate
THR = Target Heart Rate
bpm = beats per minute
Target Heart Rate (THR)
Normally during exercise, the heart rate varies depending on the intensity. These changes can easily be measured using a radiotelemetry and continuous electocardiogram (ECG) recording. The target heartrate (THR) is the desired range of heart beats per minute that usually elicits the most benefit from working out. It is also known as the training heart rate. Recommendations for this range are dependent on age, gender, physical condition and one’s previous training.
THR, recording can be stored into the memory of a microcomputer with a transmitter and receiver, which is easily portable and can be worn on the wrist.
Why it is important to know one’s target heart rate.
Target heart rate is used as a tool for exercise prescription. Results from the recordings are important in planning optimal training. This is especially important in athletes and is applicable for anyone else interested in exercise.
Monitoring intensity is also done to avoid over-training and to accurately set max limits; for example, high speed cycling does not accurately indicate the intensity of exercise, hence the monitoring of THR by the prescribed methods.
Medical professional also use heart rate measurements to help diagnose and track medical conditions.
What are the methods for measuring target heart rate?
Two methods are used to calculate the THR. The first method shows the percentage of the maximum heart rate calculated from zero to peak. Method number two represents the heart rate at a specified percentage of maximum MET (VO2max).
The Karvonen method was devised by a Scandinavian physiologist and is considered to be the “gold standard”. This method factors the resting heart rate (heart rate reserve) into the equation. Calculations are then made using the difference between a subject’s maximum heart rate and the resting heart rate.
THR = ((HRmax − HRrest) × % intensity) + HRrest
Example for someone with a HRmax of 180 and a HRrest of 70:
The Zoladz method determines exercise zones by subtracting values from HRmax
THR = HRmax – Adjuster ± 5 bpm
Zone 1: Long Slow Run .................Adjuster = 50 bpm
Zone 2: Easy Run ..........................Adjuster = 40 bpm
Zone 3: Tempo Run ......................Adjuster = 30 bpm
Zone 4: Intervals/ Speed Work......Adjuster = 20 bpm
Zone 5: Going All The Way...........Adjuster = 10 bpm
The heart rate reserve is the difference between one’s HRmax and the HRrest. If we take a typical example of someone who’s HRmax is 180, and the HRrest is 100, then heart rate reserve is calculated as:
HRmax – HRrest = HR reserve
180 – 100 = 80 bpm
The difference references the range of potential training heart rate intensities. This means if one has a large difference, then he/she has a great range of potential training heart rate intensities.
Matthew Johnson (Google+) is a certified personal trainer, nutrition expert and an on-line fitness consultant that started ChangingShape.com back in 2001.