# Heart Rate Formulas for Triathletes

It seems that there are many ways to determine your training zones from a wide variety of methods. I’m going to explain some of the more popular ways of determining your optimal training zones and give an example for each.

The aerobic training zone that I like to train in is around 70% – 80%. This would be my high-Zone 2 according to the zones that Joe Friel uses in the Triathlete’s Training Bible. In training I would even train at a little lower heart rate just to give myself some room for cardiac drift (when the heart rates rises at the end of a workout due to fatigue). In order to compare these formulas fairly, I will volunteer to be our guinea pig.

Vital Stats:
Age – 34
Max Heart Rate – 182 run, 174 bike
Resting Heart Rate – 40
Lactate Threshold: 163 run, 156 bike

Key Terms:
HR = Heart Rate
MHR = Maximum Heart Rate
RHR = Resting Heart Rate
HRR = Heart Rate Reserve or number of beats between your RHR (resting heart rate) and your MHR (maximum heart rate)
BPM = (Beats Per Minute)

The most commonly known way to determine your training zones. We have all seen this one:
220-age = MHR (maximum heart rate)
220-34= 186. 186 x .70 (70% of max) = 130
220-34= 186. 186 x .80 (80% of max) = 148

In this example my Zone 2 aerobic training zones would be from 130-148 BPM.

Karvonen Formula

Another widely accepted method to determine your training zones is this formula. It’s a little more complicated:

The formula is: ((MHR– RHR) x % intensity) + RHR = Training Zone

182 (my max) – 40 (my RHR) = 148
142 x .70 (70% of max) + 40 (RHR) = 139
182 (my max) – 40 (my RHR) = 142
142 x .80 (80% of max) + 40 (RHR) = 153

In this example my Zone 2 aerobic training zones would be from 142-153 BPM

Leger Formula

This formula was invented by Luc Leger, PhD at the University of Montreal. He uses age and a constant 205 to determine training zones.

205-(age x % of intensity)
205 – (34 x .70 (70% of max) = 181.2

This method is kind of backwards – if I try to determine my upper range of 80% I calculate this: 205 – (34 x .80 (80% of max) = 178 – hmmm – using this method, the higher my range, the lower my heart rate.

So using this method would not be a good way to determine a range.

MAF Method

This is the method developed by Phil Maffetone. This formula determines your maximum aerobic zone. This is what I call high end Zone 2.

Take 180 – Age

We need to adjust this number based on your current level of fitness. Make the following correction as it applies to you:
» If you do no working out subtract another 10 beats
» If you workout 1-2 times a week subtract 5 beats
» If you workout 3-4 times a week leave the number as it is.
» If you workout 5 or more times as week and have done so for a year or more, then add an additional 5 beats to that number.

If you are about 60 years old or older OR if you are about 20 years old or younger, add an additional 5 beats to the corrected number you now have.

From these adjustments I calculate the following:

180-34= 146

Adjustments: I work out 5 or more times per week so I will add 5 beats to that number.

Using this method, I end up with a maximum aerobic zone of 151.

Freil Method (based on Lactate Threshold):

Using the protocol in the Triathlete’s Training Bible and from my own personal LT tests, I calculated my run Lactate Threshold to be 163. From here I can calculate my Zone 2 ranges. Friel uses the range of 85-90% of LT vs. any MHR formula.

163 x .85 (85 % of LT) = 139
163 x .90 (90 % of LT) = 147

To compare all the tests I put together a chart:

 Method Low-end Aerobic Training Zone (Low Zone 2 according to Friel) High-end Aerobic Training Zone (High Zone 2 according to Friel) Age-Adjusted Method 130 148 Karvonen Formula 142 153 Leger Formula 170 n/a MAF Method n/a 151 Based on LT by Friel 139 147

As you can see, there is some disparity in these methods. Some methods are closer then others and depending on your age, some of these flat out won’t work for you. My thought is to use either the Friel Method or the Karvoren Method. Finding your maximum heart rate is not a lot of fun, trust me I have done it numerous times. My advice is to use the same method all the time, as consistency is your best measuring tool.

Michael Ricci is a USAT Level III certified coach. He can be reached for personal coaching at mike@d3multisport.com.

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