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202TSS only takes me 51.5 miles?

Saturday's Week 8 beginner HIM 3-hour long ride was my first with my new Joule (love it), thus the first time I could actually see my NP in real time and hit all my interval targets.  Uploaded the results to WKO+ and was both pleased and alarmed.

Pleased because my 3-hour TSS was 202, my highest ever.  I felt really good on this ride.

Alarmed because 202 TSS only took me 51.5 miles in 3 hours.  (And yes, I verified the Joule was zero'd and had the correct wheel size.)

Now I'm confused.  The EN Power Racing Calculator, HIM TSS table seems to be aiming for about 175 TSS to cover the entire 56-mile bike course.  How can I cover 56 miles in 175 TSS when it takes me over 200 TSS to go 51.5?  Yes, my course was a bit hilly (1500' gain), but Quassy's going to be even hillier at 2500'.  My FTP is 232, 3.5 w/kg which isn't too shabby.

As a second data point, during Sunday's steady in-the-aerobars ride I covered 28 miles in 91 minutes at TSS 105 (IF 83.5%, NP 194, VI 1.02), 500' gain, double those numbers and I'd cover 56 miles in 3:02 but at TSS 210 and on a flatter course than Quassy.  If I scale back to the goal race IF of 76% (less for the first 30') and add the Quassy hills it seems like my bike split is so slow it isn't even on the chart.

With the Joule's help, I'm hoping for a bit of an FTP boost out of Wednesday's test, but it won't be that much.

How do I do this race within a 175 TSS budget?

Comments

  • Kevin,

    You already seem to be familiar with the basic concepts of how TSS is derived, so forgive me if any of this is redundant. The first thing I'll say is that your TSS as reported on your joule in real time will not always be exactly what the TSS is in WKO. Both rely on an accurate assessment of your FTP in order to provide meaningful data. Make sure you've correctly set your FTP on the Joule in the user settings in PowerAgent, and likewise, you need to keep your FTP up to date under your athlete profile in WKO. When you do update your FTP in WKO, make sure it is from the specific date of the test going forward and not for "all dates", you don't want to affect your previously charted workouts on your PMC (performance management chart).

    Ok, moving on, TSS is of course an weighted average expression of duration and intensity (conceptually TSS = Exercise duration · Average power · Power-dependent,
    intensity weighting factor). Distance is not an input at all, but of course there is some relationship between distance and duration. If you want your TSS to be lower, you can do one of two things, ride a shorter duration, or ride at a lower power and intensity. Of course the paradox here is that if you ride at a lower power, it will almost certainly take you longer to travel the same distance, so in turn, your TSS still goes up. However, intensity still plays a greater role in this calculation than duration does, a decrease in intensity may still yield less total TSS even though the overall ride was of a longer duration.

    So for all of this, I can offer a few pieces of advice. First, as always you have to be sure that your established FTP is accurate if you are going to be able to have confidence in the TSS guidelines. Over time, I've found this to be more art than science, eventually you just develop a better "feel" for what your body is telling you and what the screen says. If you are due for a test in the very near future it's entirely possible that your FTP is now tangibly higher than your last test, which is causing a higher than actual IF to be recorded for your ride, and in turn an inflated TSS. Side commentary, we all want to rack up high TSS points in training, but it's far more important to record accurately than to record big results.

    Secondly, everyone is different and this is why we do multiple race rehearsals. The guidelines in the race execution materials are just that, guidelines. If you have confidence that your FTP is accurate, you have two opportunities to go out and take a stab at your race distance with a long brick afterwards to validate your chosen IF. I'm not sure which order I'd recommend, but in one race rehearsal, scale back your IF to keep your total TSS in line, do that long brick and see how you feel. In your other, push to the aggressive end of the IF guidance, rack up those points, and again, do that brick and report your results. If you find that you still fresh afterwards then again, maybe your threshold is not quite nailed, or maybe you are just an outlier on the curve. Absolutely nothing wrong with that as long as you know your limits.

  • Good input from Trevor, hopefully others will add theirs as well. A few of my notes:

    • Not all TSS points are created equal. From experience, we've learned that 200 TSS accrued at an IF of .86 is different from 200 TSS accrued from .80. If you've done rides like this...you'll just know what I'm talking about. Add cadence differences in there (lots of low cadence climbing vs high cadence on the flats) and you have another variable that's not accounted for in two rides of equal TSS.
    • It's not as if you go over 185 TSS and instantly burst into flames .
    • Finally, all of our TSS chart stuff is a bit of a SWAG: you need to estimate how long you're going to be on the bike course and from this extract an IF...but that entry point on the table (estimated time) is...an estimate.

    Short answer is that if you expect to be on the bike longer than 3hrs, I think you're fine to pick an IF between .78 and .8, as:

    • .8 = you're confident in your run fitness
    • .79 = less confident
    • .78 = want to play it safe.

    You then let TSS sort itself out after the race. In fact, as you don't have much experience seeing IF and TSS in real time during an HIM race, might be a good idea to not display TSS on the dial for fear of it getting inside your head...

  • Kevin,

    A few points:

    1) everybody finds that their training self, at the same intensity, goes slower than their racing self. This is a common experience in race rehearsals (usually phrased in a thread like "I only biked 6:30 in my race rehearsal, but have been expecting to be on pace for a sub 6:00, am I really that much slower than I thought?"). Riding outside of a race environment is affected by stuff like lights, stop signs, pee stops, cars pulling out, and a complete lack of (legal) drafting. All of those things contribute to you going faster (or farther, in your discussion) on the same watts on race day. So, don't worry about "how am I possibly going to go as fast as I'd hoped at Quassy?", because these things sort themselves out.

    2) Are you training in full aero gear, with aero helmet, disc cover, aero water bottle, and everything else optimized? I know that for me, that makes a huge difference as far as average speed per same watts.

    3) Once you pick your race day gears from the chart, the TSS is something you'll use for post-race analysis. There really isn't much to do with it during the race. Ride the gears, the rest sorts itself out.

    Mike
  • Thanks, gents, you've answered my questions. Somehow I'd missed the "If you expect longer than 3hrs, pick an IF and let TSS sort itself out" guidance. I agree that once I pick my IF and race day gears, I only need to monitor NP during the race; I don't even need to display TSS and IF on the Joule. I have RR2 still to go so I will try 56 miles at .79IF and see how the run feels afterward. And Mike, thanks for reassuring me that this is a common experience in race rehearsals.
  • Kevin,
    The "nuances" of racing with power are in the IM and HIM Bike Execution Webinar in the wiki. Make sure you hit that as well.
  • I solved the mystery. It's the intervals. The 3-hour ride where 202 TSS (way over the HIM target) only took me 51.5 miles was the usual 3-hour interval set, not a race rehearsal. I've had two race rehearsals now where I finished the full 56 miles in under 160 TSS, in 3:05 and 2:56. How to explain the discrepancy? I compared the power files for the same stretch of road, and compared to riding steady (VI 1.01) an interval + rest (VI 1.05) costs 63% more TSS to cover the same stretch of road, with almost the same elapsed time. That VI will kill ya. Yikes.

    I'm going to post this, with more detail, in the Power and Pace forum.
  • Isn't it because the TSS is intensity SQUARED x time? It's squaring it that makes the TSS so much higher when intensity goes up. The difference is really astounding when you compare a 3 hour ride at 85% vs. one at 70%. Assuming you just held it steady, your TSS would calculate this way (I think):



    Ride 1: .85^2 x 3 x 100 = 216.75 TSS

    Ride 2: .7^2 x 3 x 100 = 147 TSS



    So by increasing your power by only 21% you increase your TSS by 47%. If you had a really long flat road with no wind and could track your power against various speeds (from say 15-22 mph), I think you'd see that the incremental power required to get one more MPH goes up as well. At least for me, I would guess that I could cruise along at 18 mph at around 65% of FT, but to hit 22 mph I would need to go at ~90%. Put that on a HIM bike course and you get a 3:06 bike time at 18 mph, but only 131 TSS. If I did 22 mph, I'd get a 2:32 bike split, but a TSS of 206. If I could go at ~20 mph and 80% FT I would probably hit a good optimum for me...2:48 bike split with 179 TSS.



    In the example you mentioned, if you were to do 2x20'@100% + 20'@55%, your TSS would be 76.75 and your AVERAGE FT would be 85%. Contrast that with a ride where you just held 85% for an hour, and your TSS would only be 72.25. TSS is 6% higher for the interval ride even though it looks like on average you did the same work.   That's where VI comes into play.  When you spike your power, your TSS jumps up exponentially (vs. linearly), so the steadier you ride, the lower your TSS for a given average power.



    Does that help?

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