Heart Rate Training

Google “heart rate training” and you’ll get over 100 million search returns.  Even by Google’s standards – that’s a lot!  Why are there so many returns?  The fact of the matter is, fitness training, no matter the program or workout, will be the most effective if you are able to keep your heart rate in the zone that was intended for that workout.

In my opinion, excellent and timely nutrition along with exercising in a range of “heart rate zones” or “intensities” is key to meeting your body composition goals.  Notice I did not say weight – I HATE the weigh scale because it is such a poor indicator, but that is another post!

Different training programs and workouts require you to exercise at different intensities in order to be the most effective.  You should familiarize yourself with the design of the exercise program you are doing to understand what heart rate zone you should be in, and when.  That said, here are the heart rate zones you should know for training.

Healthy Heart Zone (Warm-Up) = (50 - 59% MHR [Maximum Heart Rate] - this is a great zone for you if you’re just starting to exercise. It can help to decrease body fat, blood pressure, and cholesterol.

The Energy Efficient Zone (60% - 69% MHR [Maximum Heart Rate]) – also commonly referred to as the ‘endurance’ or 'recovery' zone.  Training within this zone develops basic endurance and aerobic capacity.  Exercising in this zone burns fat and allows your muscles to re-energize with glycogen, which has been expended during faster paced workouts.  Long distance runners know this and it is the basis for their typical weekly “long slow run” where they train at a very low intensity and build endurance.  The benefits of this are greatest when you exercise for long periods of time continuously – such as 2 to 3 hours.

The Aerobic Zone (70% - 79% MHR) – training in this zone will increase your body's ability to transport oxygen to, and carbon dioxide away, from the working muscles, increasing your aerobic capacity.  In this zone, your body is able to provide energy to your muscles “on the fly” and produces few by-products like lactic acid (the stuff that makes your muscles burn when working very hard).  Aerobic metabolism is very efficient but it is relatively slow.  For runners, increasing the speed one can run at and stay in this zone is a measure of increasing fitness.

The Anaerobic Zone (80% - 89% MHR) - Training in this zone will develop your lactic acid system. Anaerobic means “in the absence of oxygen”.  During these heart rates, the amount of fat being utilised as the main source of energy is greatly reduced and glycogen stored in the muscle is predominantly used. One of the by-products of burning this glycogen is lactic acid. There is a point at which the body can no longer remove the lactic acid from the working muscles quickly enough. This is your anaerobic threshold (AT). Lactic acid interferes with energy production and so our bodies are forced to slow down or sometimes even come to a complete halt.  

The Red Line Zone (90% - 100% MHR) – training in this zone is only possible for a few minutes – even for highly trained athletes.  Fast twitch muscle fibres which produce ATP (Adenosine Triphosphate) are effectively trained at this level.

So how do you calculate your heart rate zones?   

Well there are a lot of different methods but most of us do not need ‘exact’ calculations in order to effectively utilize heart rate in our exercise regimen.  Here are some commonly used approaches.

First, estimate your Resting Heart Rate (RHR). 

Take your heart rate for three mornings in a row before getting up from bed. Once you have those numbers, take the average of the sum: Morning 1# + Morning 2# + Morning 3# = ( X) (X) divided by 3 = Morning Resting HR (MRHR) This is the single best indicator of your state of fitness. Once you have this number established as a baseline, you can use it to understand more about yourself than you can imagine. Take it again every once in a while, at least once every two weeks.  As your fitness improves, you will most likely see that number going down.   If you see an elevated number, it could mean one or more of the following:

• You did not recover from a hard workout the day before
• You need more rest
• Your body has begun fighting off an oncoming illness

Next, you need to estimate your MHR (Maximum Heart Rate). 

The most accurate method is to undertake a maximum heart rate stress test which although relatively short does require you to push your body and your heart to the very limit.  Consult your physician before doing this.  There are also a number of estimators published – here are a few.

The easiest and best known method to calculate your maximum heart rate (MHR) is to use the formula MHR = 220 – Age.

Research conducted by Gulati et al. (2010)[3] identified that the traditional male-based calculation (220-age) overestimates the maximum heart rate for age in women. They investigated the association between HR response to exercise testing and age with 5437 women. It was found that mean peak heart rate for women = 206 - (0.88 x age).

A paper by Londeree and Moeschberger (1982)[2] from the University of Missouri-Columbia indicates that the MHR varies mostly with age, but the relationship is not a linear one. They suggest an alternative formula of   MHR = 206.3 - (0.711 × Age)   Londeree and Moeschberger (1982) looked at other variables to see if they had any effect on the MHR. They found that neither sex nor race makes any difference but they did find that the MHR was affected by the activity and levels of fitness.

A paper by Miller et al. (1993)[4] proposed the following formula as a suitable formula to calculate MHR MHR = 217 - (0.85 x Age)

Evidence from Jackson et al. (2007)[5], identified the following formula as more accurately reflecting the relationship between age and maximum heart rate.     MHR = 206.9 - (0.67 x age)

Research by Whyte et al. (2008)[7] came up with with the following formulae for predicting maximum heart rates in both endurance and anaerobically trained athletes:

    Male athletes - MHR = 202 - (0.55 x age)

    Female athletes - MHR = 216 - (1.09 x age)

Now, calculate your zones.   

The calculation of a zone value, X%, is performed in the following way:

Subtract your RHR from your MHR giving us your working heart rate (WHR)

Calculate the required X% on the WHR giving us "Z"

Add "Z" and your RHR together to give us the final value

Example: The athlete's MHR is 180 and their RHR is 60 - determine the 70% value

MHR - RHR = 180 - 60 = 120

70% of 120 = 84

84 + RHR = 84 + 60 = 144 bpm

While heart rate can be reduced at a given intensity over time with an improvement in your fitness, there can also be a other factors.  Dehydration can increase the heart rate by up to 7.5%, heat and humidity can increase the heart rate by 10 beats/minute, going up in altitude can increase the heart rate by 10 to 20%, even when acclimatised, and biological variation can mean the heart rate varies from day to day by 2 to 4 beats/minute.

Sources:

Running by John Stanton.  http://www.runningroom.com/hm/inside.php?id=4395

Brian Mac Sports Coach http://www.brianmac.co.uk/

Polar USA http://www.polar.com

Dynamic Sport http://dynamicsportspt.com/