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05 Jan 2005

Polar Heart Rate Monitor
Hi, I want to incorporate more cardio work into my exercise programme and got a Polar Heart Rate Monitor for this. The only thing is I don't completely understand it. I have worked out my 'zone' for an optimal workout and work for 20 mins in this zone (it's my first week) - I plan to build this up to 30 mins in a few weeks. Is this enough? Will it be effective? Also, the Polar calculates kCal's burnt during a session - what is a kCal? How do I work out how many KJ's I've burnt?

Please help!
Thank You
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Expert
FitnessDoc
fitnessdoc

01 Jan 0001

Hi toni

The use of heart rate monitors can add enormously to your training, but the bad news is that used incorrectly, they also take away from it. it's quite difficult to explain, because there is a lot to sift through, so if you do hit any specific snags in the future, please don't hesitate to ask and i will try to be more specific.

However, as far as general principles go, the most important thing is that you must remember that what is true for one person is not necessarily for another. So, this pertains to the zones. If you and a friend were to exercise together on the same machine at the same speed, you might find that your heart rate is 150, hers is 170. So who is doing the right thing? Well, according to zones, perhaps you are too low, and she is too high? This is the tricky thing, and the answer is that probably neither is incorrect. You see, we are all different, so it stands to reason that some people will just have a higher heart rate than others. therefore, i am not a fan of using zones to train. i would rather use effort perception - you could, for example, use a scale of 1 to 10, and then aim to go at 7 out of 10, for 45 minutes, with a few bursts at 9 out of 10 in between.

So, where does the heart rate monitor come in then? Well, the best way to use it is to compare heart rate within your own training. For example, if you do a regular training session of 20 min on the bike at level 5, and your rate is between 150 and 155, then perhaps in 2 months, you will see it is at 145. This is a good sign of improved fitness. That's the best way to monitor your training - I am a firm believe that you must MONITOR the training, rather than DICTATING it based on heart rate. i know many people disagree, but it's vital to realise that it's not just your heart that you are training - the heart is but one of many organs and systems, and it's not all that important, it's just a sign of how the body is coping.

As for the KCal, a kilocalorie is just another form of measuring energy (like with meters and yards). One kCal is equal to 4.2 kJ, so you can convert this way. Just a word of caution - the machine may be very accurate, but it may be quite inaccurate. Also, remember that you are only measuring it during exercise, whereas your metabolic rate stays quite high long after you finish training. Therefore, it's very easy to over or under estimate the kJ that you are burning if you just look at the heart rate monitor. When you consider that if your daily kJ intake is out by about the equivalent of a biscuit and it can cause major weight loss or gain, then maybe you realise that the merits of measuing kilojoules in and out are perhaps a little questionable.

Good luck
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