Running Log: Monday, July 12 2010

River Kelvin -> Vet School -> and back (with Isla in Baby Jogger)

9.1 miles in 1:04, average pace 7:04/mile (avg HR 153 bpm)

Notes: I recently looked into heart rate (HR) training levels more closely and found a helpful distinction between max HR and *working* HR. Although the equation to determine one's percentage of working HR requires a couple additional steps, it is supposed to provide a better guide for the degree of effort that should go into each type of training run.
The basic equation is Max HR - Resting HR (x percentage effort) + Resting HR.
So, let's say I want to target a 75% effort for a basic aerobic conditioning run. In my case, this would be approximately 190 - 40 = 150 x .75 = 112.5 + 40 = 152.5 Voila! I aim keep my HR on today's run around 152-153 bpm.
Now, where things get a bit more complicated is finding a consensus on what percentage one should target for, say, optimal aerobic development. For marathon conditioning, most coaches seem to recommend keeping most runs around 70% working heart rate. In my case, this would be 140 bpm. However, this seems to be a more conservative aerobic effort - i.e. one that better enables twice a day running and over 80 miles per week. Running at a faster aerobic effort for this amount of training would (for most people anyway) result in a lowering of blood ph and neuromuscular breakdown.
Arthur Lydiard suggests that aerobic conditioning be done more aggressively (even while maintaining massive training loads!). Contrary to public opinion, Lydiard does not recommend long slow distance, or LSD. This takes too long in his opinion, so runners ought to aim for a pace much closer to their aerobic threshold. Based on some of Lydiard's comments in his discussion of aerobic conditioning, I take this to be an effort of 75-83% working heart rate. To help put this in perspective, half marathon pace is often said to be 85% working heart rate. Only special runners with a huge foundation can handle big mileage at this sort of pace (e.g. Chris Solinsky, who still does 5:45/mile pace on his 'easy' runs - this is not LSD, but it is Lydiard-style training).
I conclude that most runners, if they hope to handle twice-a-day high-mileage training, need to keep the effort at 70% for most runs. If you can't put in this amount of time (most people cannot!), then the effort might be safely and more productively taken up to the 80% range. Personally, I try to keep my 'steady' runs at 70-75% when I am trying to run everyday (with perhaps 2-3 twice-a-days) and achieve a volume of +70 miles per week. When I can only get out 5-6 days a week with no doubles, I try to push the threshold level, running my 'steady' runs at close to 85%. Most runners can only manage the latter schedule, so I think they would benefit from aerobic conditioning at a faster pace, rather than the oft recommended 70%.