Updated 13th November 2019

Amazing improvements are possible for cyclists and triathletes

The pros and cons

The previous blog in the series looked at some of the research that has been done around using Power or Heart Rate for training in a lab setting and its results. This blog post will outline some of my experience of using both as a cyclist and coach.

Heart rate monitor

In my experience of heart rate and power meter training, heart rate monitoring is a very reliable tool.

It is very useful for preventing burnout and over-training as well as improving fitness.

Heart rate monitoring demonstrates the body’s response to training loads and lifestyle and is a great training tool when used correctly.

Most people who compete or participate in endurance events could benefit from use of a heart rate monitor.

They are relatively inexpensive and are often included as part of a package with bike computers.

General fitness

People who are just trying to increase their basic level of aerobic fitness can also get great benefits from using a heart rate monitor to control the pace of their efforts.

Heart rate

There are a number factors that can influence heart rate:

  • Age
  • Fatigue
  • Temperature
  • Dehydration
  • Low glycogen levels
  • Anxiety
  • Caffeine or other drugs

These may all increase or decrease the heart rate on any particular day. There is also an issue with Cardiac drift where the heart rate increases over time during exercise even though the workload might remain constant.

This variability is sometimes used as a reason to use Power instead of heart rate for training.

However anyone who has used power will also know that it’s also very variable when done in real time and a riders power can vary from day to day.

But, over time the heart rate monitoring will give consistent patterns. Below is a good example of how the resting heart rate reduces as fitness improves.

resting heart rate reduction

Benefits of heart rate monitor

  • Is relatively inexpensive.
  • Is very good for controlling efforts up to lactate threshold level, 80 to 90% of Maximum Heart Rate. Most endurance athletes’ training sessions are spent at 60 to 80% of maximum Heart Rate. A heart rate monitor can track this very well.
  • Training zones can be set out very well based on maximum heart rate or lactate and heart rate tests.
  • Heart rate remains fairly similar over time, while the speed/ power achieved increases at the same heart rate as fitness improves.
  • There’s no need to constantly retest.
  • Improvements in fitness can be tracked through reduced resting HR and a quicker return to resting values after exercise.

What a heart rate monitor doesn’t do

  • Measure the power being applied.
  • Give feedback of power used in training or races.
  • Measure shorter intensive anaerobic efforts from a few seconds to a few minutes.

Power meter

As power is one of the things that can be the difference in winning or losing, it is an important metric.

Training with a power meter is especially good for controlling top end efforts above threshold compared to heart rate.

It is also excellent at measuring improvements or non-improvements in power output..

Power meter analysis of races can be used to plan future training. It can also be used to model training for future race circuits.

Benefits of Power meters

  • Excellent for reviewing race efforts.
  • Controlling the training load above the lactate threshold.
  • Measuring overall training and racing workloads.
  • Measuring Improvements in workloads over time.
  • Targeting specific intensities to improve.
  • Pacing efforts.
  • Understanding how hard you are working when racing.
  • Some good software packages for reviewing data.

What’s not so good about  power meters

  • Having to retest very often to track changes.
  • There’s a lot of data to interpret.
  • Can lead to over-training very quickly if used in isolation.
  • Can mislead pacing strategies in time trials if form is great or poor on the day.
  • See Tom Dumoulins performance below
  •  Tom Dumoulin


Changes in power and heart rate

Below is two tests of the same cyclist. The first test (Blue Bars) in December and the second test (Orange Bars) in April of the next year. It demonstrates the improvement in fitness with decreased heart rates at similar workloads / watts (bottom Line)  in April when compared to December. Click on photo to expand

changes in heart rate and power blog

Perceived exertion

Perceived exertion is still very important. What is Perceived exertion Experienced cyclist know when the effort is not right.

When a zone 2 Watts and heart rate feels like a zone 3 or 4 effort?

Experienced cyclist’s will know when to push on or back off according to perceived exertions and heart rate response.

Whatever the power output or heart rate, perceived exertion is always an important part of a session. If it feels too easy or too tough, it probably is.


  • Perceived exertion is fine for leisure cycling.
  • Heart rate is useful for road racing cyclist’s, triathletes and preparations for major Sportives like etape du Tour and Marmotte
  • Power is useful for endurance cyclists, triathletes and track sprint events.
  • The ideal world is to use them all together in a sensible way.

Check out and Buy my Introduction to Cycling Booklet Here 

Paddy Doran High Performance cycling coach at Peak Endurance Coaching

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