Surpassing Thresholds

Last month’s training was all about rebuilding following a long, lazy vacation. This month was about going beyond my previous levels and starting to reach new heights.

Month four (May) finished with a CTL of 81, up from 74 prior to my vacation.

My VO2 max and mFTP were right where March’s numbers had been as well, so the post-vacation rebuild was definitely complete:

TTE remained at about 45 minutes, but at 292w as opposed to 275w in March. (For a discussion of TTE, see my month one post.)

Boosting Functional Reserve Capacity (FRC)

My FRC is continuing to creep up as well (the red dashed line below), which I’m happy to see since this is one of the key areas I’m working to improve. (For an introduction to FRC see my month two post.)

I’m now at 22.6 kj, having begun my first month at ~15 kj. That’s a big improvement (nearly 50%)! According to one chart from TrainingPeaks, an FRC greater than 22.9 kj is considered high, while 13.5-22.9 kg is considered “medium”. So I’m just on the cusp of FRC greatness… maybe.

But FRC is probably best measured in proportion to body weight instead of straight kilojoules, since a larger rider will logically have more capacity in their larger muscles. I can’t find a chart showing a breakdown of kj/kg looks like, but my guess is since I’m a larger cyclist (84kg/185lbs) my FRC isn’t actually that impressive.

Here’s an example of what FRC looks like, applied to cycling performance:

If my FTP is 300 watts, and I have an FRC of 15 kj, what is the highest average wattage I can hold for 10 minutes?

  • 10 minutes = 600 seconds
  • 15,000 joules/600 seconds = 25 watts
  • 300 watts FTP + 25 watts of anaerobic power = 325 watts. This is the maximum power I can sustain for 10 minutes.

What does boosted FRC translate to in my actual cycling performance? I’ve noticed I can follow multiple attacks without blowing up. I don’t get dropped as often on short climbs. And if the race isn’t too crazy I can launch my own attacks while still having something in the tank for the final sprint. In short–FRC is a game changer for races!

The Workouts

Here are two workouts coach Shayne gave me multiple times in this training block. Both are good examples of V02 max and SST work:

The VO2 work, in particular, has been so helpful to me–even though it’s painful to do. Doing those intervals above threshold trains my body so I can handle race attacks, and even dish some out myself. This has helped my Zwift B racing go from “hang onto the pack until I get dropped by an attack halfway through” to “stay with the front the whole race, launch a few attacks of my own, and still have a finishing sprint.”

Watch for my next post as I tackle another month’s training block, including putting in some big miles on a cycling trip to Girona!