Today I wanted to put in another solid effort so after yesterday’s tough workout I made sure I ate and drank enough so I’d be ready to go hard again this afternoon. I intentionally waited until late afternoon so I’d hopefully be more recovered. I headed out to the garage to do the entire workout on the rollers. I set out to do VO2 intervals. I planned on doing three sets of 3×4-minute intervals, with recovery periods of four minutes between reps and eight minutes between sets. This is one of the workouts from the sample training plan in the book Training and Racing with a Power Meter.

I started with a short warm-up then got right into the intervals. The first set felt good and I used the usual 1/3rd opening on the Killer Headwind fan unit on my Kreitler rollers. On the second set I experimented with closing the fan all the way and using the big ring. It felt more like riding on the flats with a tailwind, but it wasn’t any easier to maintain my wattage. The first one I did in a big gear that gave me an average of 98 RPM, while the others were at my usual TT cadence of 103-105 RPM. Ironically, all three were exactly the same average wattage! And no, I didn’t have the PowerTap set to display average interval wattage…I was just really consistent during that set! The higher rotational inertia of the rollers when set this way, probably helped (speed of the wheels and rollers are much higher with the fan closed). I definitely noticed my PowerTap’s current wattage display didn’t fluctuate as much during this set.

For the last set, I reverted the fan back to 1/3rd open and used my small ring. Opening the fan not only increases resistance but increases the amount of air the unit blows on you for cooling. By this point, I was getting toasty, even in the cool garage with another fan blowing on me from behind. Just for fun, on the second to last rep, I went to the other extreme; trying an even smaller gear that gave me an average cadence of 110 RPM. That was the worst interval of the bunch! But all three intervals of the last set weren’t that great…they were all below my L4/L5 border. I think my legs were toast by then. But looking at the “When to stop interval repeats” table on page 77 of The Book, they were still within an acceptable range, so I’m glad I didn’t quit (even though I really wanted to).

Overall it was a good ride, especially considering yesterday’s effort. Though my wattage for the intervals wer on the low side, I’m glad I actually completed the workout I set out to do. I’m going to continue to be conservative when I do VO2s and make sure I complete each workout, while slowly increasing my wattage over the next few weeks. Total ride time was 1:35 with a TSS of 117 and 231/263 ave/norm power.