Especially since watching BBC's Horizon - Monitor Me programme, I have become increasingly curious about the benefits of monitoring my body. Not only are there more gadgets available than every before but there are more accessible apps available to use on your mobile phone. My most recent purchase is the Instant Heart Rate app which is a heart rate monitor requiring no external hardware. Although there is a free version on the app store, I paid £1.49 for the full version to avoid annoying ads and so that I could store more than 5 results.

Firstly, why am I so keen to monitor my heart rate anyway? Besides the fact that I am super-curious and like to experiment, your resting heart rate is a fairly good measure of fitness. Generally, your RHR should slowly decrease as you become more and more fit because your heart becomes more efficient at pumping blood around the body, especially if this is combined with a reduction in fatty deposits in your arteries. It's important to consider that the RHR of different individuals can vary hugely depending on age, gender and of course, activity.

According to the resting heart rate indicators that I have found, I generally fall into the 'good' category based on my average resting rates taken when I have just woken up or just before I go to sleep. I'd love to be able to improve my fitness enough to get this consistently into the 'excellent' range.

As well as indicating fitness, heart rate can also be affected by dehydration, on-setting illness and insufficient rest. So in theory, your heart rate could predict how you will feel in a few hours or even days before you could!

So, how does this awesome app work? In order to detect your heart rate, you must gently cover the phone's camera lens with your finger. As your finger changes colour slightly as the capillaries inside expand and contract with each heartbeat, the LED light on your camera will show these changes.

Of course you can also work out your RHR without any fancy gadgetry. Simply count the beats! I like to do this by placing my forefinger and middle finger of one hand on the inside of my opposite wrist in a place that I can feel my pulse and then start a stopwatch. Ideally, count for the full 60 seconds for a most accurate result but you could also count for 30 seconds and double it, 20 seconds and triple it, 10 seconds and time it by 6, and so on. The smaller the number that you multiply by, the more reliable your result will be.

It can also be beneficial to monitor your heart rate at many other times other than when you are resting but that's a post for another day!

P.s. Remember my post about my beloved Sleep Cycle app a little while back? The developers of Instant Heart Rate, Azumio, also have a similar sleep app called Sleep Time, which the heart rate monitor can integrate with, if you are interested!