Get with the beat

The humble heart rate monitor may have been usurped by the power meter, but it is still a vital tool in any rider’s training toolbox

Things move fast in cycling – and we don’t just mean you after following a Cyclist training plan. Where heart rate monitors were once all the rage, now it’s all about power data. But that doesn’t mean you should consign heart rate training to the bin.

‘Using a heart rate monitor has several plus points,’ says coach Ric Stern. ‘It can help you pace your efforts, especially longer ones. If you use it in conjunction with a power meter you can see how heart rate responds to your power output so you can better dial in your effort.’

‘Crucially your heart rate tells you how your body is feeling,’ adds coach Tom Newman.

‘Also, heart rate monitors are inexpensive, reliable, compact and easy to understand.’

That’s not to say they’re perfect. ‘The main downside is that heart rate is simply the speed at which your heart is beating. Increasing intensity, or power output, will raise your heart rate to match the demand but you don’t know your cardiac output. That’s your heart rate multiplied by your stroke volume – the amount of blood per minute leaving your heart. Stroke volume was thought to level off at about threshold pace – roughly the maximum you can maintain for one hour – but we now know it continues to increase with intensity, so heart rate alone doesn’t give you the full picture.

‘There are other complications,’ continues Newman. ‘Hot weather may elevate your heart rate and cold weather may restrict it. Fatigue or illness can also lower it so you maybe can’t hit the numbers you want to. Also, over the course of a long workout, heart rate isn’t stable for the same intensity and may progressively rise due to a phenomenon called cardiac drift.’

Again, none of those are reasons not to use heart rate data. No training metric is perfect on its own, and this one is far more useful than most.

Ramping it up

To maximise the benefit of heart rate training you need to know your maximum heart rate (MHR), which will determine heart rate zones in which to train. The simplest way is using a very basic equation (for example 220 minus your age), while the most accurate way is in a lab.

‘A ramp test, where power output increases to exhaustion, will produce your MHR and maximal aerobic power [MAP] so you can set both heart rate and power zones,’ says Stern. ‘But doing a maximal 10-minute time-trial effort and then ramping it up slowly over the next five minutes to an all-out effort will also give you your MHR.’

Another option is to visit the British Cycling website, where you will find a 20-minute heart rate test that’s more accurate than using your age and a lot cheaper than a lab-based ramp test. Once you have the results you’re ready to use heart rate training zones (see box) to gauge your effort and target fitness gains.

‘You can see how your body responds over time,’ says Newman, who recommends riding a local route in one of two ways: at threshold pace, noting your time and average heart rate, or at a set heart rate, noting your time. The idea is that you’ll get faster for the same effort, or training at a certain pace will get easier.

‘You can do anything from 15 to 60 minutes,’ says Stern. ‘You just want a route with minimal traffic or junctions where you have to stop.’

Knowing your heart rate at various efforts is handy when you combine it with power metrics. ‘Say you’re doing a steady effort on a road bike at 150W and 140bpm,’ says Stern. ‘If you then ride without a power meter you can estimate your power from your heart rate. Or say you do an FTP test and don’t feel 100%. Your power output might stay the same but if your heart rate goes down you know you’re getting fitter and would do better on a good day.’

This is an example of heart rate offering physiological feedback and it helps to think of heart rate and power as opposite ends of the same spectrum: the effort you’re putting in and the performance you’re getting out. This is why they’re so useful together.

You can also elicit balanced fitness gains by ensuring your heart rate is decreasing across the board, from endurance rides to maximal sprints. ‘All areas of intensity are important, whatever your training goal,’ says Stern.

Your training plan should comprise four to five rides per week, made up of everything from one long ride to intervals every week to 10 days, depending on how well you recover.

‘If you race you may want to increase the number of intervals, as well as the frequency, to build speed and power for specific race scenarios,’ says Stern. ‘If you’re a time-triallist you may want to add in functional threshold power work, and for a sportive you might want to add in more medium-intensity endurance training at zone 3 to build fatigue resistance.

‘You can pace all of these sessions using training zones,’ he adds. ‘The only issue is with intervals, because when you do efforts at greater than FTP your heart rate may not respond rapidly enough for you to get in your zone – or it may take several intervals before you reach the zone – but your intervals are part of a longer ride so the data is still relevant.’

Heart rate monitors still have a place, then, despite the rise of the power meter.

‘Most new ideas drift down from the pros to us mere mortals, but what suits your needs?’ asks Newman. ‘If you’re riding club runs do you need the latest carbon wheels that aren’t very robust? And do you need the outlay of a power meter if you can train using your heart rate?’

‘Power data is where the world is at now, but your heart rate is still relevant for training,’ adds Stern. ‘If you don’t want or can’t afford a power meter you can still get great results. You’ll also need to use feel to try to gauge how hard an effort is once you go above your FTP, but there are worse ways to ride.’

‘Heart rate and power are opposite ends of the same spectrum: the effort you’re putting in and the performance you’re getting out’