I bought a PowerTap at the start of the year and have been using it consistently to monitor my training. As a numbers person I find at a real aid to training at the correct intensities, which were often higher than I imagined.
If you know your FTP then riding 2 * 20 minutes at just below that twice a week will improve your power a lot. reference[/url]
I went from doing that session in late Feb at 3.5W/KG to 3.8W/KG in three months but with my average working heart rate decreasing from 160 to 154 per interval.
As a reference I’d say I’d be mid pack expert at MTB, somewhere near njee20, course depending
Numbers, love ’em.