Comments on: A profligate purchase and an interesting stress test

By: canute1

canute1 — Thu, 26 Nov 2009 08:52:29 +0000

Stravros, Thank you. I think we are both being over simplistic is interpreting one Poincare plot as healthy without taking context into account.

As I have described in my blog, in general the spread at right angles to the 45 degree line is indicative of parasympathetic activity and the spread along the line is more strongly influenced by sympathetic activity. In many circumstances, parasympathetic activity si healthy as it tends top be associated with rest and recovery.

One circumstance where spread away from the 45 degree line is probably unhealthy is when the points are located far off the line in the manner indicative of ectopic beats illustrated by Dr Yang in the reference you quote. I do not believe that the spread in my ‘blue; chart is characteristic of ectopic beats, though I am well aware that at my age ectopics are a potential concern, though even in this is debated – with the majority of the evidence indicating that minor numbers of ectopics (or of ventricular tachycardia) are nor unhealthy if there is no other evidence of heart disease. However I am still a little concerned whenever I see evidence of ectopics in my records – but I do not think ectopics contribute substantially to the blue plot shown on this posting.

The other thing to say is that too much parasympathetic activity or an absence of sympathetic activity can also be a sign of poor health. Although the pink plot of data after my illness suggests diminished ratio of parasympathetic to sympathetic activity, if you read subsequent blog entries you will see that I moved from the relative sympathetic excess shown in the pink plot to a state of parasympathetic success which I considered was an overprotective response to possible excessive training.

By: Stavros

Stavros — Thu, 26 Nov 2009 00:30:16 +0000

Hello,

Actually you are reading the data in the poincare diagram wrongly.

The pink series of data represent a healty state of the heart, while the blue are not.

Have a look at:
http://www.physionet.org/events/hrv-2006/yang.pdf

Thanks!!

By: canute1

canute1 — Sat, 18 Jul 2009 21:18:56 +0000

Rick, I found the tone the article irritatingly sensationalist, but nonetheless, I agree with the message. Heavy cushioning and/or pronation control are almost certainly bad because that impede the development of good muscular control of foot fall. As a youngster I spent the summers barefoot, and as a marathon runner in my twenties, my favorite shoes were Onitsuka Tigers – which 40 years ago were very thin soled and lighter than plimsolls. Now that the fat pads have disappeared from under the balls of my feet, and my downward protruding metatarsal heads have become more prominent, I prefer a slightly thicker sole. I still bounce barefoot on trampoline to keep the intrinsic muscle of my feet in reasonably supple state, but I do not run barefoot on roads or cross county to minimize abrasion and bruising of my feet. If one accepts that forefoot landing is better than heel-strike, shoes with padded heels are simply an obstruction that interferes with elastic recoil of the muscles and tendons. What is your current view about shoes with inner-springs?

By: RICKS RUNNING

RICKS RUNNING — Sat, 18 Jul 2009 17:40:03 +0000

The painful truth about trainers: Are running shoes a waste of money?
http://refreshingnews9.blogspot.com/2009/04/painful-truth-about-trainers-are.html

By: Carsten

Carsten — Fri, 17 Jul 2009 10:50:17 +0000

I have sent FirstBeat an email asking about the options for non-professional for obtaining a license to Firstbeat Sport and I am still waiting for a reply. I own a Polar RS800 and I have seen the Own Optimizer feature but I was not able to find any information about how it works. I am not sure about the Poincare plot since I basically don’t understand this graph and I need to do more research.

By: RICKS RUNNING

RICKS RUNNING — Fri, 17 Jul 2009 06:13:59 +0000

Thanks Canute, I look forward to reading your views

By: canute1

canute1 — Thu, 16 Jul 2009 20:41:08 +0000

Carsten, You are correct in pointing out the Firstbeat market both the Sport and Health software to professionals. I have a legitimate professional interest in Firstbeat Health, and I had not realized that it would be unavailable to non-professionals. At this stage, I am not sure what the best option for the non-professional is. I will be very interested to see how the Polar Own Optimizer works out. In principle I think that a calculation based on change on HR and HRV on standing shortly after awakening in the morning might be a sensitive measure. My experience so far with the Poincare plot is also promising, though I need to understand more about the apparent parasympathetic surges visible in my data. Also the assumption that scatter along the 45 degree line is purely due to sympathetic activity is certainly an over-simplification. Over the next few weeks I hope to explore various different options and will post the results on my blog.

Rick, Thanks for your question about heel v mid-foot striking. I am flattered to be described as wise, but if I were truly wise I would avoid answering this question. Because I am prepared to run the risk of being foolish, I will give a simple answer: I consider mid-foot (or fore-foot) is better. Nonetheless, a large number of sub-elite athletes run very well with heel striking. The reasons why I consider mid or forefoot striking is better would take too long to present in this response, but I will post a detailed account of my views on this question on the weekend.

By: RICKS RUNNING

RICKS RUNNING — Thu, 16 Jul 2009 11:28:58 +0000

Help;
As a man of great wisdom can you settle a pub debate between me and a friend.
TO HEEL STRIKE OR MIDFOOT STRIKE!
My friend is a good runner and works in a runners shoe sop, he says to land heel first is the most natural and best way to run and if it wasn’t the best way the shoe companies would not make 80-90 % of there shoes for heel strikes, he even told me the great haille had shoes made with extra padding in the heel for his world record at the marathon as he is a heel striker!
THE CASE AGAINST HEEL STRIKING
First watch this video
http://www.youtube.com/watch?v=EAW87NsiGuI
It looks like haille is midfoot striking to me!
If you ran bare foot you would not last long on your heels, as you are landing on bone and missing using the foot arch for absorbsion.
The Africans, the best runners in the world land fore-mid foot.
if you land heel first you are overstriding.
the shoe companies got it wrong, aiming at joe the jogger who has poor running form. landing heel first.
midfoot is the most natural best way to run!
PLEASE BE JUDGE ON THIS CASE AND LET US KNOW WHO IS CORRECT.
THANKS

By: Carsten

Carsten — Thu, 16 Jul 2009 11:17:59 +0000

Thanks for a great post. I am quite interested in the assessment of stress/recovery based on R-R data but unfortunately Firstbeat Sports and Firstbeat Health does not seem to be available to individuals. Do you know of any other software that combines R-R data and recovery?

By: Ewen

Ewen — Wed, 15 Jul 2009 08:35:35 +0000

Thanks Canute. If the RS800cx does the Poincare plot, I’ll keep that in mind. My RS 200 has been reliable, even surviving a stack into gravel when I tripped over one run.

The cadence facility will be useful too. A running friend of mine has the RS 200 with the footpod – he said the cadence count works well. The distance is not as accurate though, as even when calibrated for the user it can be out by up to 5% depending on terrain and speed.