The less of me, the one with the heart

I'm not actually sure what I was thinking, but I have a Nike Sportswatch, and this allows me to track my exercise.

One of it's capabilities is to link to a suitable heart rate sensor. And being as how I had nothing better to spend more money on I invested in one.

Bit of a mistake really. Maybe.

It works ok, and gave me some readings, but having done no research the numbers it came up with were meaningless.  So I had to go investigate using the trusty Google and Wikipedias

What I found was a couple of interesting things, but I'm not sure if I'm nearer understanding or now just frightened.

Resting Heart Rate for MEN
Age	18-25	26-35	36-45	46-55	56-65	65+
Athlete	49-55	49-54	50-56	50-57	51-56	50-55
Excellent	56-61	55-61	57-62	58-63	57-61	56-61
Good	62-65	62-65	63-66	64-67	62-67	62-65
Above Average	66-69	66-70	67-70	68-71	68-71	66-69
Average	70-73	71-74	71-75	72-76	72-75	70-73
Below               Average	74-81	75-81	76-82	77-83	76-81	74-79
Poor	82+	82+	83+	84+	82+	80+

As can be seen on this chart, your resting heart rate can vary with your fitness level and with age. I'm wavering around Good to Excellent, according to this.

But then the point of a heart rate monitor is to show your heart under the stress of exercise. So I had to find that out. And I came up with this

• The most commonly used formula is to take       your age (in years) away from 220. For example, if you are 34, your predicted max heart rate is 186 bpm (220 - 34). The formula was derived from a range of maximum heart rate studies in 1970 by William Haskell and Samuel Fox.


• A study in 2001 with healthy adults found a more accurate formula of 208 - 0.7 x age (from Tanaka, H., Monahan, K.D., & Seals, D.R. (2001). Age-predicted maximal heart rate revisited. J Am Coll Cardiol. Jan;37(1):153-6.)

So I can derive then that my maximum heart rate should be around 171 (I'm old).

And then I found a handy chart that shows me what that looks like in terms of exercise effort heart rate to Maximum heart rate

Table of heart rate at training intensities from 50-90%

age	50%	60%	65%	70%	75%	80%	90%
50	120	130	135	140	145	150	160
51	120	129	134	139	144	149	159
52	119	129	134	139	144	148	158
53	119	128	133	138	143	148	157
54	118	128	132	137	142	147	156

Going back to the data then,  I've had the heart rate monitor on for 3 exercise things and have rates between 146 and 152, somewhere between 75% and 90% (on average), and a range between 70 and 90% overall. Average being a good thing as looking at the data, it says 163 at one point on one of the three days (last night it topped at 158).

So why am I worried. Well 75%, or 80% or 90%  - how do you know that ?  They 'feel' the same to me. I'm pushing as hard as I feel I can on most days, some days I hear the music, others I don't.  I don't want to 'back-off' yet now, I'm conscious that there is a limit to how much I should push, and this is going to change the way I do things, even if I pretend to myself it isn't and that I'll just ignore it. I won't.

Wheck out here http://www.topendsports.com/testing/heart-rate.htm for where I took my data and advice from.