The Importance of the Heart Rate

First of all let’s start by defining your resting heart rate.  The Resting Heart Rate (RHR) is your heart rate when you’re at rest; lying down, awake, and not having recently exerted yourself.  RHR is pretty simple to find.  First, find your pulse on the inside of your wrist, just below the thumb, using two fingers to feel the pulse.  If it cannot be felt hear you can check it on your neck over the carotid artery (just off the centre of your neck).  Count the beats once you feel your pulse, counting the first beat as zero and count for 15 seconds.  Take this number and multiply it by 4 and you’ve got your resting heart rate in beats per minute.  The normal range for a resting heart rate is between 60-100bpm, although some don’t always fall in this range.  Many athletes have resting heart rates between 40-60bpm and elderly individuals often have higher heart rates.  A few tips to ensure accuracy: be well rested, avoid stimulants (e.g. caffeine), and ensure you are well hydrated.  

 

Generally speaking, the lower the number the better, the lower the number the more fit you are.  Why?  Simply, because the more blood your heart can pump with each beat the less times it has to beat each minute to supply adequate blood flow to the body (i.e. a larger heart capacity).  How can you lower it?  Again, the simple answer, by engaging in regular aerobic exercise. 

It is important to note that everyone’s RHR is different and there are several factors that can affect it.  Some of these factors include: caffeine (increases), how well rested you are (lack of rest can increase), dehydration (increases), and even overtraining.  The last one may be surprising, but a rising resting heart rate could indicate that your loading on too many high intensity workouts causing your body to fall behind in repairing itself, leading for poor performance and injury

What’s the relevance?  It can be used to calculate Target Heart Rate (THR) zones for training.  This is done through the Heart Rate Reserve (HRR) or Karnoven method (about the most accurate we can get when prescribing training zones).

How do I calculate?  Using the formula below:

THR = (HR Max – HR Rest) x % Intensity + HR Rest

HR Max = 220 – age

E.g. For a 20yr old with a resting hear rate of 55bpm wants to work at 60% of his HRR.

60% Intensity THR   = (220 – 55) x 0.6 + 55

                             = 175bpm

What should your target HRR training zone be?  Well that really depends on what you’re training for and the intensity your looking to attain.  Here is a general breakdown of the different training zones and intensity according to the HRR method.

<20% HRR	Very Light
20-39% HRR	Light
40-59% HRR	Moderate
60-84% HRR	Intense
>85%	Very Intense
100%	Maximal

As a general recommendation for aerobic training working between 50-85% HRR (moderate to intense) is a good guideline.  Anything lower than this you are going to have a hard time seeing results, and anything higher is going to be incredibly difficult to sustain.

Ultimately, having an understanding of your resting heart rate, and what happens to your heart rate when your exercising can be a very helpful training tool.  Try out a heart rate monitor the next time you go for a run and see for yourself!  Side note of caution: Don’t rely on the heart rate recordings on cardio machines.  If you’re going to measure your heart rate invest in a heart rate monitor watch and chest strap for more accurate readings.  You can pick one up for anywhere between $100-200.

That’s all for now,

Lindsay

“Repetition is based on body rhythms, so we identify with the heartbeat, or with walking, or with breathing” – Karlheinz Stockhausen