Sunday 28 August 2011

Big Heart

Abina always said I had a big heart, or was that mouth, I can never tell. However according to this article (when you read past the section on sudden death in athletes) a larger than normal heart explains why my heart beats more slowly than it would had I maintained a sedentary life. When it comes to pumping more oxygenated blood around the body to supply energy to muscles during exercise the heart can either beat faster or pump more with each beat. As there is a limit on how fast your heart can beat, no matter how fit you are (an elite athlete has the same maximum heart rate as his/her equivalent couch potato) the only adaptation the heart can make in response to the constant pressure of training is to pump more during each beat (stroke volume), which requires a bigger chamber, 33% bigger and more. The surprising thing is that the heart adapts very quickly - within a few weeks of commencing a sustained training regime. Likewise the adaptation reverses quite quickly once we stop exercising regularly - a bit like any muscle really. So for those that train intermittently it would appear that the main thing that changes is the size of their heart. A low resting heart rate and a larger than normal heart in an average person is an indication of a probable heart block, hypertension or heart failure, so if your are in the middle of endurance training it is probably a good idea to say so when visiting the doctor - although if you suffer from any of the above and are in the middle of endurance training................
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While my resting heart rate is at an all time low of 34 to 35 bpm (I manually measured 172 beats in 5 minutes two weeks ago = 34.4 bpm - taken before rising) and my training HR is quite low, I have also noticed that my racing HR has come down since I started running, with last weeks 10k averaging 158 bpm and a max of 166 over the closing stages - can my heart not beat faster than that in a race. My 10k PB in April 2008 (38:15 - 6:09 pace) had an average HR of 168, which maxed out at 177 over the closing stages (10 bpm higher). Maybe I'm not pushing myself hard enough, although increasing age does account for some of the reduction (roughly 3 bpm over 3 years). So while I am getting more bang for my buck I have less bucks than I used to have. Still I am encouraged by my best ever race result, my 10 mile PB last year, where my HR averaged 161 for the 6:16 average pace.
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Training
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I have spent the last 2 weeks in West Cork, where training has gone pretty well. I followed the Shannonvale 10k with a Sunday long run of 20 miles covering miles 5 to 24 of the Clonakilty Marathon route, topping the week with 64 miles (highest since ultra training in May)
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This week I was just shy of 60 miles as I cut back today's long run to 15 miles, which is all I need for my next key race, the Charleville HM on 18th September. It also doubled as a taper for the Dingle Marathon, which I am pacing next Saturday. I did however up the pace to provide some training challenge and averaged 7:25 pace over the partially hilly course, stopping sporadically to take photos, which explains the suppressed Avg HR of 126.
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McMillian gives me a 1:29:07 half marathon (6:48 pace) for my 40:03 10k last week, which, to be quite honest, is an easy target. Without the hill I reckon I would have covered the 10k in about 39:30, which still gives me a relatively soft HM target of 1:27:54 (6:43 pace). Maybe that's where my fitness is at, but i'll surely improve over the next few weeks, how much will the Dingle Marathon blunt my speed? - too many unknowns so I settled on 6:40 pace as my HM training pace (1:27:24) for this weeks specific endurance run - secretly hoping to get under it.
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I had planned on 4 x 2 miles @ HM pace (with about 2 or 3 minute active recoveries - hadn't really thought it out, maybe 90 seconds would do as this is likely to be my penultimate specific endurance session before the race). The day before I had completed an "easy" 12 miler where everything felt relatively effortless for the 7:31 pace. This "flow" continued into the warmup for the 4 x 2 mile session where the pace came down to 7:10 without too much effort. I had picked the flat road around Clonakilty Bay for the session running from Inchydoney to Ring Village (lower) and back. I settled into a pace just below 6:40 which felt relatively comfortable to maintain and, approaching the two mile mark, decided to run on to 3 or 4 miles before taking a break. I ended up running for about 28 minutes (27:56) before running out of (flat) road and turned back with an average pace of 6:34 on the Garmin. The initial headwind on the return leg kept the pace in the 6:40's but it eventually came down to 6:36 - covering the return leg in 28:09. I decided to round the session up to an hour and ran on for another 4:30 before cooling down on the mile home. I covered 9.21 miles in 1:00:37 with an average 6:35 pace which is more encouraging than my visit to McMillian. Could I have maintained the pace for another 3.9 miles? More than likely. Will the Charleville course be as flat? It's billed as a flat course - well then at 6:35 pace I would come home in 1:26:18. Getting that bit closer to my PB all the time.
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One of the benefits of running the back roads of West Cork for the last two weeks, apart from the scenery, is that you get to spot where all the blackberries are - so I returned later for a bit of foraging.
Finally some photos form this morning run. It will be difficult to return to suburban running. If the sun come out for Dingle next Saturday it will be a spectacular run.

6 comments:

  1. Awesome pics, Grellan! And I'm quite jealous of that low heart rate. I agree, that half marathon time should be a breeze for you. You'll crush it. Good luck!

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  2. nice pics and great local running routes..

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  3. Last photograph reminds me of my wedding (10 years ago!) - Waking up to that view.

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  4. Richard, i'm 11 years ahead of you!!! same view.

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  5. From the photos you've snagged some good weather over there. Last day of winter for us today - bring on spring and summer!

    Sometimes not being able to hit the same ave/max HRs in racing is due to being extremely fit and/or not rested enough before the race. If you had 4 days off my guess is you'd have no trouble hitting former HRs. When you're very fit the heart is not a limiting factor to speed i.e. the leg muscles give out before the heart.

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  6. I'm thinking about coming to Ireland within the next 5 years and looking at those photos has me almost convinced!

    That is some resting heart rate, in fact, if I'm not mistaken it is lower than Lance Armstrongs' when he was racing!

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