Diary of a Sub 40 10K #2

Last week I said I'd be talking about eating this week, but recent events have prompted me to focus on HR instead.  (We'll get to eating either next week or the week after).
HR is fascinating as a very accurate measure of performance, and especially measuring improvements in performance, and as such HR is a very effective (and useful) training tool.  Before I begin, one thing to note: using a HR monitor becomes especially interesting when you use it at around the same time of day, on the same course.  The idea is to make yourself the only variable.  Once you change times, temperatures and route profiles, it's more difficult to credit oneself with a good day.

So on that basis I'm pleased to report that on last Sunday's 6km run (May 27) I was able to carve another 30 seconds off my personal best on that course, one week after slicing more than a minute off the previous record. If this sounds like all in day's work - hold it right there!  Just a few short weeks ago I was running that route in 31: 15 and couldn't seem to go any faster.  Literally.  I mean over two consecutive weeks I was purposefully GUNNING for the record, hoping to go under 31 minutes - but all I managed was  a 31:15.  Guess what: 7 days later I went - alone - to the road, and filled with sheer determination and chutzpah, all I managed to do was run a second slower.  My heart rate average was 158, maximum 167. 

What has changed since then?  Well I've been on a low carbohydrate diet (one of the three initiatives I mentioned in #1) for the past 3-4 weeks, and today when I weighed myself I tipped the scales at 86.2kg - the lightest in more than a few months.  So running faster has happened thanks in large part to simple weight loss.  But psychologically it's been helpful to have a specific target in terms of exertion, to measure the run against - in REAL TIME.  What I mean is, at any moment, whilst running the course, I can look at my HRM and see whether I'm not going hard enough or not.  So what was helpful on the 27th was having this data (from May the 20th) in the back of my head:

 For starters, note the time it took to reach the psychologically significant level of 160 BPM.  Just over 10 minutes, or almost 2km.  Remember this is running along an uphill gradient for at least the entire first 10 minutes.  Also interesting is that there's a slight dip in HR after the 25 minute mark - exactly when one ought to be digging deep and speeding up for a final surge.  Even so, this run represented a real breakthrough - if breaching 30 minutes was big after struggling to break 31, imagine the surprise going 28:52 without going for broke.  I mean, look at that HR: 159 BPM average, that's just 2 BPM higher than when I ran 31:16.  My maximum HR here is just 3 BPM higher.  Point is, when I looked at these values I had an idea that another chunk of time was there for the taking.

So I set myself about the task of trying to push my maximum HR over 170.  I decided the perfect opportunity for that was on a weekly run with Craig Booth up Albrecht Road - one of the steepest, sharpest climbs in the city.  So here's what happened.

Strange for me - but despite putting in a big effort, I wasn't even able to hit 170, let alone go higher.  So the idea for the next hard run was simple - SEE HOW HARD YOU CAN PUSH YOUR HR.  The focus was more on maximum HR than average HR, and the idea was to get it elevated sooner rather than later.  Which is why I reached the 160 level in about half the time on the 27th - around 6 minutes.

You'll also notice that unlike the run on the 20th, my HR doesn't level out nearly as much, and there is no dip after the 25 metre mark although it is fairly flat.  The gray line represents the gradient, so you can see why it's not straightforward to maintain a high level of exertion - here the road goes downhill fairly steeply.

It remains interesting to me that even though I amputated 30 seconds off my PB I managed to raise my average HR by a mere 2 BPM over the previous record.  I was happy to get my HR MAX to 172 (also just 2 BPM more than previously). So the mark to beat when next I go over Albrecht will be 172. And my sights in the 6km have to be on going under 28 and getting to 27 - which is 4:30 min/km, and halfway (in my mind) to getting to the ultimate goal which is a sub 40 minute 10K.

Sidenote: Today (Tuesday, 29 May) was the first run since last year in my Vibram Fivefingers.  Ran 7km at around 6 minutes per kilometre.  The left side of my right foot's heel felt a little bruised; otherwise the run felt very comfortable.  We'll see how my calves hold up tomorrow morning.

 UPDATE: On Wednesday I got my HR up to its highest yet, 173 - 5 more than the previous week - going over Albrecht.  See above: