I never made such a long Tempo Run before, as my past of "interval trainer" was more based on running 4x1000m at "burning legs" speed and felt duly exhausted after the 3rd interval ...
Also I felt very important to gradually increase the length of the tempo run because they really show the improvement of your aerobic condition.
A usual 20/25 mins effort involves pushing hard from the start and does not give a real indication of how fast the HR would drift from the ideal LT training zone to the "over the top" area.
While running at least 35 min let you settle into a good speed and observe the feed-back from the heart and legs more carefully. Ideally, you must rise gradually into your LT training zone (for me 170 to 180 bpm) and stay comfortably in that area.
to set a pace, the table from "Daniel's Running Formula" gave me a pace to respect of 3'39"/km (5'53"/Mile). (if you do not have this book, you are making a mistake...)
It all went very well ... I was running very easy and I avoided on purpose to push more than the target pace, even if the HR was still not in the target zone for LT training until Km8.
At the end, I totaled a 43'12" that is a very fine 3'36" pace very steady and easy. Still have stamina to push the last 2k into the 3'2x' area.
Could I have gone faster ? I guess that hitting earlier the 170bpm and than rising to 175/177 I could have been more in the 3'32" range ... but "train not strain" seems a good idea in this phase.
As I said before, I am now in the final tune-up stage of the training period and I find the workouts more and more easy to complete. Also the recovery is very good. It is a good indication that the training is going in the right direction, but I believe that for every runner at this stage there is a dilemma whether to push more and gain some little extra plus or just go with the current form ...
to close, I post also the HR curve (included speed and cadence) because it is really a nice graph!!
(AMENDEMENT: I am struggling to transfer the Polar curve into Jpg or Tif because I could not find a conversion SW that I hid somewhere ... the chart will be uploaded asap ... be patient)
- Do you use the tables in "Daniel's Running Formula" ? (all Daniel's tables remove a lot of subjectivity in the training, perhaps it is no the right way to improve the sensibility to your own running feelings and physical conditions, but overall I find them quite challenging and sensible)