How to train for triathlons with a heart-rate monitor to boost your endurance and speed.

Triathlon Training Heart Rate

Heart rate monitors can be your best friend when training for triathlon

Heart-rate monitors are pound for pound the single most powerful training tool available to triathletes. In this age of cycle power meters and GPS devices it would be easy to overlook the humble heart-rate monitor, but to do so would be to ignore one of the few golden tools of tri-training. And costing from as little as £30, there’s really no excuse for training without one.

Back in the 1990s pro triathletes like Paula Newby-Fraser and Mark Allen were dominating the sport, using heart rate for all their key sessions. Six-time World Champion Allen even said: “During my 15 years of racing in the sport of triathlons
I searched for those few golden tools that would allow me to maximise my training time and come up with the race results I envisioned. At the top of that list was heart-rate training.”

Heart-rate training enables you to focus in on different training intensities. For Allen this meant training for several months below 155 beats per minute, to develop his ability to use fat as a fuel. For you it may mean something else, like training at higher intensities to improve your top-end speed. Heart-rate training allows you to work at the intensities that are right for you.

The problem with heart-rate training is that people buy a fancy watch and then don’t know what to do with it. They take it on their workouts, occasionally stare at the number on the screen, wonder what it means, and end up training exactly the same way as before. There’s nothing particularly complicated about heart-rate training, but it does require a little bit of forethought to get the most out of it. This feature should provide you with everything you need to get started with heart-rate training.

Work out your zones

This is the first and most important step to effective heart-rate training. We’re all different, and our hearts all beat at different speeds as we train. Working out personalised training zones means we can tailor our training, improve our weaknesses and build on our strengths.

Some coaches and physiologists recommend having three different heart- rate zones, some think four is best, while others prefer five or six. At the end of the day, the number of zones won’t make a huge difference, so just choose one method and stick with it. See the ‘Your Training Zones’ box for ideas on how to do this.

Make a plan

Once you’ve worked out your zones, you’re almost ready to train. You just need some kind of plan, so you can schedule your heart-rate training sessions in a progressive way. Mark Allen used to train exclusively at his fat-burning pace throughout the winter – for him this was anything under 155 beats per minute. Then in the spring and summer he would add in two or three higher- intensity sessions to boost his speed in time for the race season.

When it comes to training, having a progressive plan is vastly better than having none at all. So set your own schedule, get a friend to help, hire a coach, or use the training plans we provide in Triathlon Plus (see page 80). We give our intensities descriptively, rather than by heart rate, but by reading the key it’s easy to see which zones they’d fall within.

Don’t be a slave to numbers

No matter which method you use to work out your zones, heart-rate training involves a small degree of inconsistency. Your heart rate changes each day depending on factors like stress, heat, altitude and diet. So you need to work within a range, and not worry about one or two beats difference here or there. It’s always better to work with a margin for error, and that way you’ll have enough flexibility to accommodate hills, weather conditions and training with friends without having to drop behind when your heart rate goes a few beats too high.

Plot your progress

The real magic of heart-rate training comes when you look at your progress over time. Mark Allen would measure his speeds and times versus his heart rate after each session, and analyse it over weeks and months. By doing this he could tell whether or not he was improving. As soon as his speed at 155 beats per minute had reached a plateau he would change his training, adding in higher intensity work. Unless you monitor your progress over time, you are missing out on a golden opportunity to see how your body is reacting to your training.

Your Personal Training Zones

The gold standard for working out heart-rate training zones is a blood lactate test. It’s not ideal for everyone because it doesn’t come cheap, so to get you going, we’re going to show you how to calculate training zones yourself. All you’ll need is your resting and maximum heart rates.

Work out your resting heart rate

  • Lie down and relax for 20 minutes, in a quiet room
  • Have a clock or watch in clear view, that measures seconds and minutes
  • Count your heart beats for one minute, with your finger on a pulse, or with your hand over your heart
  • Avoid caffeine on the day

Work out your max heart rate

There are various ways of estimating your maximal heart rate, but I’ve never found them reliable. The best way is test yourself in real life. I always have an idea of my maximal heart rate from high-intensity track running sessions, or hill reps on my bike. But a more accurate method is to do your own stress test:

Find a good hill that takes about two minutes to run up. The test begins with five minutes’ running before the hill. Accelerate towards the hill, achieving around 85% effort at the base of the hill. As you hit the hill, keep your speed by increasing your effort. Keep an eye on your monitor and look for your highest heart rate as you run to the top of the hill.

Your Training Zones

Once you’ve worked out your resting and maximum heart rates, you can divide your heart rates into personalised training zones.

  • Zone 1 Recovery Zone – 60% to 70% of max

Useful for encouraging blood flow, to aid recovery after a tough workout.

  • Zone 2 Aerobic Zone – 70% to 80% of max

Training in this zone will boost your endurance and the efficiency with which you use fat and carbohydrates as fuel.

  • Zone 3 Anaerobic Zone – 80% to 90% of max

Training like this is thought to enable you to delay fatigue caused by lactic acid.

  • Zone 4 Maximal Zone – 90% to 100% of max%

Training in this zone is only possible for short periods of time, and will help you to develop your top-end speed.

Making the calculation:
  1. Subtract your resting HR from your maximum HR, giving you a ‘working heart rate‘.
  2. Calculate 60 and 70% of your working heart rate.
  3. Add these two figures to your resting heart rate, and hey presto you’ve worked out your Zone 1 heart rates.
  4. Do the same for Zones 2, 3 and 4, and you’re there. is the online home of Triathlon Plus – the best source of triathlon training advice, triathlon gear reviews and triathlon news.

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