Guesstimating TSS (I know, bad)

Having just ridden a double this weekend in Norcal (206 miles and 18,600 feet of vertical), I was trying to make sense of what something like this does to your fitness and training.

I chose not to use the Powertap (I know, but I was having wheel issues and did not want to mess around with it), so I am trying to get a handle on the rough TSS. My benchmark is a 9 hour ride I did this summer (9 hours riding, 10 hours total) with ~640 TSS on the powertap that was 140 miles with about 12,000 feet of climbing.

From the start on Saturday to lunch it was 116 miles with about 11,000 feet of climbing, and that took me 7:45, including rest stops but with no drafting. After that the heat (not brutal but still 100+ in the sun for the backside of Mt. Hamilton and Sierra Road) sapped my strength and my foot acted up so I spent another ~6:15 riding and another hour off the bike (including chatting with my family at the last rest stop). So I rode for at least 13.25 hours. My IF for the 9 hour ride was ~0.75, and I would expect it to be less for this ride but not by much since my FTP is about the same and I rode almost exactly the same average riding speed (~15.5 mph) on a course with slightly more climbing per mile.

Am I thinking about this the right way? If so, it seems the TSS should be in excess of 900, which seems like a heck of a lot.

Any advice would be appreciated. Also, I am hoping to do another ride in three weeks of similar duration and I will ride the PT wheel for that, and I will post the file here so we can compare the data if folks want.

Something isn't adding up here, 9 hours at 0.75 IF yields ~506 TSS, not 640 TSS.
Well if you assume with your discomfort issues the IF dropped to say 0.65, then your IF for 13.25 hours would be 559 and if your IF dropped to 0.6 it would be 477. Even at your previous IF of 0.75 the total TSS would be 745. Not sure how you estimated 900.

The relationship is:

TSS = IF^2*hours*100

That squaring reduces TSS quickly with dropping IF.

I think you'd be safe to estimate in the vicinity of 500-600 TSS for the long ride at a slower pace than the ride you did last summer.
-Dave

Each .01 on the IF estimate represents a delta of about 3% for the ride TSS, so..... yeah, this is not the kind of ride you want to be guess-timating on.

Dave,

You are right, I am half brain dead and was going by memory for the IF and then forgot the squaring (duh). I knew something did not seem right for the TSS but was too sleep deprived to pinpoint it.

I went back to the file and the actual IF for the 9 hour ride was 0.775, not 0.75 so the TSS was ~540, not 640.

In terms of the IF drop, I rode fine to the end, but needed to take off my right shoe at each rest stop till the feeling came back.

To put the rides in perspective, the summer ride was the first 140 miles of a double century course, and I rode the first 9-10 hours on Saturday at about the same PE (and average speed) -- I summited Mount Hamilton despite some issues in just under 10 hours total, so that is 135 miles and almost 14,000 feet the same time as it took to ride 140 miles and climb 12,000, which seem like roughly equivalent performances to me.

Where does this leave me? Well, I think it's safe to assume the TSS should be more than 540 but not more than 650.

Thank you for setting me straight and I hope to have some hard data to share after May 9.

BTW, what was your TSS for LOTOJA?

517 with an IF of .73

Cool! I still can't believe how fast you rode. Since you have done the Death Ride why not rock the Terrible Two out of Santa Rosa. You should have a shot at the record, no? Plus, that is among the most beautiful rides on Earth imho.

I also searched for old posts on Lotoja and ultra events and I realized I had posted data about last year's failed attempt at Devil Mountain (my laptop got swiped and I had not yet backed up the last six months of data so I thought it was lost).

Last year was really stupid (trying to do this coming off a two week flu and a corresponding CTL of about 30), and TSS for the 160 miles and ~16,000 feet to the top of Sierra was 590. This year I was three hours faster to that point and was already eating lasagna at the finish -- go CTL of 62!

Had to do something other than ride so I ran today for the first time on forever and I am hoping to get my CTL up to 100 and then do some Vo2 work and taper for the Terrible Two in the third week of June.

Thanks again for helping me think through this!

In a word, no.

There are many, many folks out there who are faster than I am during ultras. The Death Ride was enjoyable, but we rode it for fun and really had a great day. I much prefer racing events in the one to four hour range where pack dynamics and tactics are key. Two LOTOJAs were enough to show me that I'd prefer to race shorter events or stage races and save sportifs for touring and enjoying the ride.

But who knows maybe I'll hook up with Wattsamatta from Tahoe for another good long day tour in NorCal this year. I'm sure we won't be chasing any course records if we do.

-Dave

I hear you, my favorite events are the Euro sportives but I no longer live there (85 miles and 14,000 feet is the bomb, with Euro pros riding for kicks).

That being said, the TT record is 10:50, and someone who was very competitive in ultras was just a few minutes ahead of you at Lotoja in 2007, so it is possible for you -- just saying

See y'all at the Death Ride.