Running Notes by HJL

Logged another long run with hill intervals today, increasing the pace from 10:00 to 9:30 but staying with the 5% incline. The faster pace appears to have resulted in a 5-8 point increase in HR during the steady state portion of the run, ending up at around 145 compared with around 139. This is the longest run on this cycle

One of the reasons I like using the heart rate monitor and data recorder is to get a quantitative view of how training is going. The hill interval portion of the graph is more interesting to look at. Part of what I’m after at the moment is to get a better sense of what my current LT (lactate threshold) pace is.

One of the objectives for longer interval training is to improve the body’s ability to function in the presence of lactate. The higher level of effort raises the body’s energy demand beyond what can be generated through primarily aerobic metabolism, and the anaerobic systems become more important. The body’s aerobic energy systems are much more efficient than the anaerobic systems, but have a limited rate of energy release. Training for endurance sports, such as marathons or triathlons, focus on developing the body’s cardiovascular system to increase its aerobic capacity, and also on increasing the lactate threshold, which allows sustained physical effort at a higher, partially anaerobic level.

During incline or pace intervals, you’re moving the body’s energy production in and out of mostly aerobic and mostly anaerobic modes. It is important to select levels of effort that allow recovery to an aerobic effort and also pushes into the anerobic range, but without requiring one to stop. If you simply continued at an anaerobic level of effort, you’d have to stop fairly soon, but an interval workout allows you to spend more time training at a useful level of effort. The first few intervals typically feel easier than the last ones, but the goal is to find the level of effort is difficult but can be maintained. I usually try to do at least 3 repetitions.

The adaptation we’re after is an improvement in the body’s ability to buffer lactic acid. This increases the sustainable level of energy output for longer distances. If you spend too much time too anaerobic during an endurance event, you typically exhaust the readily available glycogen (”hitting the wall”, “bonking”) which is unpleasant and dramatically reduces the energy available to skeletal muscles. The LT pace corresponds to a level of effort that is faster than comfortable, can be sustained for an extended period of time (an hour or more), and if exceeded, would quickly require that you slow down to recover from O2 debt.

Part of my current planning challenge for this year’s Big Sur Marathon is that my physiological performance is very different (worse) than where it’s been over the past few years, so I don’t have a good sense of what my sustainable paces actually are. I also don’t have a clear sense of the root cause, other than some test data showing that my breathing is slightly off.

Based on today’s data, it also looks like I can hold 9:30 pace without any problems for two hours. The HR graph isn’t trending up, either, so I may already be able to manage 9:00 pace for two hours, especially if I’m not starting off with hills.

On this training cycle, so far I’m not having any sore muscles. All of my training issues (other than not breathing well) have been with mental fatigue and elevated HR. At my current level of O2 intake, I don’t think I’m pushing the muscles very hard. We’ll see what happens with longer runs and faster paces. Although allergy season is starting, I think the medication is helping more than the allergies are hurting.

Today I ran a set of hill intervals on the treadmill. I like running intervals on the treadmill since everything is completely repeatable and doesn’t depend on my ability to manage pace and effort. The data from the heart rate monitor is also relatively interesting to look at afterwards.

This is the first set of intervals I’ve run on this training cycle. I find it psychologically helpful to complete at least 2 miles of 5% incline (today I did 3 miles) on a hill day, as this roughly corresponds to the ascent at Hurricane Point, the longest hill on the Big Sur Marathon course.

I normally run my intervals for 5 minute duration, rather than by distance. For hill interval days, I pick an “easy” pace and only change the incline between 0% and something between 5% and 8%. Whether it’s hill intervals or pace intervals, I normally try to keep a fixed level of effort for each rep. A 5% incline seemed to work out ok today. Unfortunately, at the moment, my “easy” pace is around 10:00 instead of 9:00 or 8:30. Today that put my HR at around 135-140, while the last couple of hill intervals ended up close to 170.

I’m still baffled by my elevated HR compared with log data from past years, but at least I’m continuing to make progress on this training cycle.

Continuing to cautiously ramp up mileage and longer runs. The heart rate monitor is returning better data now, after a new battery. Yesterday I logged 9.5 miles on the treadmill, at 9:00 pace. Taking out the warmup and cooldown, the HR data for the middle 80 minutes looks substantially better than a similar run a few weeks ago. I’m still starting out 10 points higher than my 2005 baseline, but I’m not getting the steeply increasing heart rate anymore, and it seems to be tracking about 10 points higher than the baseline all the way out now.

Some of the improvement is just adaptation to having resumed longer runs, but I’m starting to get some improvement in my breathing. It still doesn’t feel great, but it’s definitely not as bad as last month, and I’ve also stopped having random episodes of feeling out of breath while sitting at the computer.

It’s hard to gauge my current conditioning right now, but having the flatter, if elevated HR curves, is encouraging. I may try resuming a little bit of hill and T pace training if things stay like this, working from whatever VDOT seems to fit. The fallback plan will be to just continue on base building.

My goals for Big Sur emphasize having an enjoyable run, as opposed to going as fast as possible, although I’m still holding out hope for improvement over last year’s time (3:50:34). Last year I got beat by a 70-year-old (who turned out to be George Hirsch, founding publisher of Runners World).

…especially when I already feel like I can’t breathe properly. What are they thinking?

This morning I headed to the gym for a 60+ minute easy run. I’m still not breathing properly, although I noticed that things got better after about 45 minutes, which is encouraging, if weird.

My heart rate monitor strap seems to need new batteries. When the batteries are low, it starts throwing out readings that are usually fractional multiples of the actual heart rate, such as 1/2, 1/3, or sometimes 3/2 or 4/3, or 60 (presumably from AC line interference). It can also read randomly high, such as the 172 I saw today while warming up (my observed HRmax is something like 180).

Ended up doing about 8 miles at 9:30 pace, mostly at around HR 140-145. This is 15-20 points higher than where I would normally expect to be (120’s) at this pace.

The replacement for my old Timex data recorder arrived. I don’t have the Timex Trainer software loaded on this computer, I’m hoping there have been some bug fixes since the last time I tried it.

In my experience, the data recorder and software usually works pretty well, and is a great improvement over trying to log workout heart rates and paces manually. However…

I purchased my first data recorder shortly after they went on the market, having already gotten the Bodylink heart rate monitor and the predecessor Ironman GPS unit. At the time, both the hardware and software seemed a little buggy, but still pretty amazing for the price point, just over $50. The lack of user interface makes the data recorder a little challenging to use sometimes. There is a single button and a single LED which flashes timed patterns in red or green to indicate various conditions, which can be difficult to see in bright sunlight and can take a while to interpret. In particular, it’s easy to miss the red-and-green flash which indicates low battery, which soon leads to the unit shutting itself off.

The most unfortunate experience I had with the data recorder was using it at my first time running the Big Sur marathon and having the Timex Trainer software choke while uploading the 4 1/2 hours of data. I had the speed smoothing function turned on and I’m guessing that it hit an exception somewhere while chewing on missing or spurious location data. I was fairly annoyed about this, since I wanted the training data, and actually worked out the HR part of the data using the flash memory dump feature in the Timex software.

Hacking the data out of the firmware wasn’t my first choice, I actually contacted Timex to see if I could either have someone rescue the data from the memory dump or send some documentation so I could do it myself. I got as far as extracting the time and heart rate data, which was moderately useful in planning for the next time around.

There’s now a project on SourceForge, sponsored by Timex, which provides the logger.dll code used to interact with the data recorder over USB. I haven’t gotten around to trying it, partly because I haven’t had a data recorder for a while, so I may give it try sometime.

My notes on hacking the Timex data recorder are posted on the main blog in the running category:

• Hacking the Timex Bodylink, Part 1
• Hacking the Timex Bodylink, Part 2