Power Meters v Heart Rate Monitors…

Power meters are quickly becoming the ‘Marmite’ of cycling, love ’em or hate ’em. Or rather, do you really need one or not?

Firstly, a power meter isn’t any good to you unless you know exactly how to use it and what all that stuff means on your bike computer in relation to your overall fitness and health – that’s assuming you have a bike computer. And it’s also assuming that you have a crank set that you can fit a power meter to.

The cost of a Stages power meter is at least £700. But that’s not the total cost. You also need the crankset to fit it to, so if you haven’t got 105 crankset and above then you’re going to have to fork out that cash as well. And then also you’re going to have to have a computer for your bike that can deal with power in order for it to be useful.

But the question really is, is this all necessary to be a good cyclist? Is this necessary to lose weight, keep healthy and make good fitness gains on a bike? The answer is no, it certainly is not!

The biggest claim i’ve read, seen or heard about the benefits of power meters over HR meters is that HR varies whereas power doesn’t. I beg to differ.

HR varies according to your state of health and your state of recovery. If you ignore these signs and just exercise to power readings then you can easily find yourself going into overtraining and injury territory – that’s bad!!!

Anyone who cares anything about their health, fitness and wellbeing should have a HR monitor. They are so cheap these days and can be used with a cheap wrist monitor or a smart phone and you don’t need to modify your crankset or buy expensive wheels to fit one to.

And HR monitors don’t just measure the BPM of your heart, if you have a smart phone you can also measure your heart rate variability (HRV). And HRV is the most important one for anyone interested in fitness.

Basically, every morning when you wake up, you have a wee and then you go and lie back down in bed and put your HR monitor on. Chill out for 5 minutes, relax, breath calmly, meditate. Then start your smart phone up with an app like Elite HRV. And every morning, under the same conditions, you measure your HR and your HRV with this simple to use little app.

If you’re stressed out mentally your HRV will off normal, if your overtrained or under-rested then your HRV will be off normal. And you can judge weather you should be exercising and how hard you should be exercising accordingly.

For example, i did my fastest 40km on a Sunday morning, the next morning my HRV was about 5 points lower than normal. This is quite normal if you’ve just done a personal best 40km the day before. I then have a choice, i can have a easy day that day or i can go and do some more training. I chose to do a 10km run.

Now i knew when i did that 10km run that my HRV the next day would be even lower, it was about 10 points lower than normal, and at 10 points lower you really shouldn’t be doing any exercise that day. Which is what i had planned. I knew when i chose to do that 10km run on the back of a 5 point lower HRV that the day after i had absolutely nothing to do but sit and watch videos and chill out, so it was worth pushing my body into that zone as i will get better fitness returns off it. However, if i had known that the next day i had to do some physical work like digging the garden or whatever, then i would never have done that 10km run as i would have been diminishing any returns on my exercise by forcing my body to do physical work when it’s in a severely overtrained state.

Back to power meters. Some people say that you should just put a power meter on your bike and push the watts and that’s all you need to know to make fitness returns. But how do you know if you’re in an overtrained state, a fully recovered state, a not well state, etc., by looking totally at your watts? You don’t!

You may have picked up a virus, like flu, for example. Now if you’ve had that strain of flu before you will be immune to it, but your immune system will still need to jack up and deal with the virus to prevent you from becoming ill. If you use HRV every morning then you will know that there’s something not right even if you can’t actually explain it at the time and exercise, or not, accordingly. If, however, your immune system is trying to fight off a virus and you don’t know it because you haven’t checked your HRV and you go and push all those watts like normal then your immune system will not be able to fight off the virus and you will become ill and then what will happen to your fitness levels and training?

The other value of HR and HRV is that it can also work the other way. In that i mean that sometimes one can wake up having intended to go and do a 50 mile ride and you feel tired and down and can sometimes convince yourself that something’s not right, you’ve probably overtrained or didn’t get enough rest and so you kill the alarm, go back to sleep for 2 more hours and never do that 50 mile ride (be honest, we’ve all done it! 😀 ). But by checking your HRV and HR you can see that everything physical is well within normal parameters and you instantly know that the laziness you’re feeling is all in your head, not in your body. It may be that you had a dream that ended badly or were in the middle of a good dream that the alarm clock interrupted and so that has left you feeling a little depressed, but the HR and HRV lets you know instantly that you’re physically fine and you ain’t got no excuses, your mindset changes instantly and you get your bones out of bed and go peddle. As soon as you start peddling you realise that it absolutely was all in your mind.

So instead of being all, ‘I’ve got to be like Bradley Wiggins and he’s got a power meter so i obviously need one too and i have to train to power like Bradley does’, just remember that the power meter is the last measurement in his arsenal. Before he ever gets to that his team doctors and physios are keeping a very close eye on his health and fitness with a whole barrage of tests and then telling him what power to train to according to that whole host of data that they collate from those test. And unless you know how to measure accurately your blood lactate levels and VO2 mac levels etc., and train up to a standard that warrants getting a power meter then i would suggest that your money could be spent on more useful training equipment.

Best wishes.