What is OpenID?

We've all been told over the years that periodisation is an important part of training for endurance sports, and necessary to maximise your performance in the competitive season. The trouble is that it requires discipline, and sometimes just a blind belief that a particular training plan downloaded from the web, or given out by a coach will have the desired effect. In particular, we are supposed to do many weeks of aerobic base building at speeds far lower than those we hope to achieve during the summer events, before being allowed to ramp up the pace. During this phase there's not much feedback that the medicine is working, unless you do tests such as the MAF (Dr Phil Maffetone's site) test on a regular basis.
One of my aims when designing ithlete was to help users (including myself!) see whether training is having the desired effect, and it now looks like the evidence is coming together. At the beginning of this year, a paper was published in the European Journal of Applied Physiology that used the same standard HRV measure as ithlete to track the progress of runners preparing for 10K events. The runners worked to a training program tailored to their own heart rate zones, and in all the runners whose 10k times improved, resting HRV showed a progressively increasing trend during the 8wk training period. The conclusion from this is that if your HRV trend (the thick blue line on the chart) is steadily upwards, then the aerobic component of your fitness is most likely increasing!
How big a change can you expect? by way of example, I have been doing 70%+ of my training below my aerobic threshold for the past 3 mths, and I think the attached screenshot speaks for itself.
A gain of 5-6 units is quite noticeable, not only on the chart, but on my level of comfort when doing longer runs & rides. I can also train every day now without feeling fatigued, which I never could before. Of course there is still the need to increase intensity and do intervals, etc in order to condition the anaerobic component of fitness and be ready for competitive events, but I will not start that until the improvements in base aerobic fitness have stopped coming.

If anyone else who has been using ithlete for a while has had similar experiences, please share them!