Big Data

As Triathletes, we spend a large portion of our training and racing on a bike in the aero position.  While we certainly aren’t “cyclists,” we are most like time trial cyclists than any others (criteriums, road, cross, mountain, etc).  The standard distance time trial in cycling is 40k (often referred to as 40k ITT (for individual time trial as opposed to TTT for team time trial).  While I am hardly the cyclist that I once was (or may someday be again), I love this discipline because it is simple, there are no tactics (other than pacing), there are no interactions or drafting (since every rider is started at least 1 minute apart), it is just you versus the clock and how hard you can push yourself without popping.  To equate it to running, it is something between a 10k and a half marathon (for most people).

The added side benefit of this, is that these events take most people somewhere in the range of an hour (some will go 55 minutes, others will go 75 minutes, but you get the point).  Having an effort like that, which is almost purely aerobic is a “gold standard” of truly defining your current fitness and your FTP (functional threshold power).  We are always trying to estimate this number with a ramp test, or an 8 minute test, or a 20 minute test, but just like running, hardly anyone can produce an effort in training like they can when they are competing and chasing others.

In order to help people see the value of pacing, racing with power, and training with power, I thought I would do the following “deep dive” on my numbers from the time trial this past weekend. 

First key thing to note is that it was a 4 lap course of 10k.  Each lap was essentially 5k with a tail wind and 5k back with a head wind, thus 8 u-turns.  When I started the day, I had estimated my FTP at 188, I thought I had a little more than that, but I wasn’t positive and as all my athletes will tell you, I nearly always preach to start conservatively and just get better.  First, let’s take a look at Lap 1:


Segment Duration (min:sec) Distance (miles) Ave Power (Watts) Normal Power (Watts) Max Power (Watts) Ave HR Ave Cad Ave Speed
1st 5k 7:01 3.1 203 201 289 160 92 26.6
2nd 5k 8:56 3.1 222 220 385 170 92 20.8


I was totally unfamiliar with this course, so I definitely suffered from a little bit of caution on that first lap, just trying to figure out what was where and when the turns would come and how to navigate the road conditions.  I planned to keep that first lap around 200 watts and that mission was accomplished, but you can immediately see 2 things, first, on the way back to the start house, I produced 10% more power, that wasn’t intentional, this is common with headwinds.  Even though we are rational people and we can see the screen and control our legs, it is just easier to unintentionally produce more power when that additional resistance is applied to you (same with going uphill).  That isn’t the end of the world, it is just something of which you need to be aware and manage.  On a day like this, nothing is going to kill me, it is only a 25 mile ride; but on a day like Ironman, messing up like that can lead to a lot of walking come marathon time.

Second thing to note, on the way back, more power, WAY lower speed.  This is why I PREACH to all my athletes, throw the speed out the window, don’t have it on your screen, don’t care about it, don’t believe it, don’t trust it, it can do nothing but screw you over. If I were planning to set a target time, here is where a very bad never ending spiral would occur.  Notice the difference in time from 1st 5k to 2nd 5k, nearly 2 minutes, I produced 10% more power for an segment that lasted 29% longer . . . that is already bad enough, but what if, I was pacing the race off speed, and I see that my speed dropped by a whopping 29% and I tried to hold that 26.6 mph which would probably require 300 watts with that wind, I would be TOAST.  Moral of the story, your legs are what matters and your legs control the power, they don’t (exclusively) control the speed.  On the next lap, I got a little more comfortable with the course, I started to read my body a little better and was able to edge things up slightly higher:


Segment Duration (min:sec) Distance (miles) Ave Power (Watts) Normal Power (Watts) Max Power (Watts) Ave HR Ave Cad Ave Speed
3rd 5k 6:44 3.1 215 213 355 168 93 27.6
4th 5k 8:46 3.1 222 220 346 170 93 21.3



Another couple of takeaways here, first, despite producing the same average and same normal power for the headwind section in lap 2 as in lap 1, I was 0.5 mph faster.  Why?  I don’t know, maybe the wind died down some, but again, speed can’t be trusted on the course and this again demonstrates it.  Same power, same section of course, different results.  Also, despite the headwind/tailwind, I am starting to get a little more consistent with the average power, hitting 215 with tailwind and 222 with head wind, happy about that one and happy that 2nd lap showed more power than 1st.

Heading into 3rd lap, I was starting to hurt some and my thoughts were: can you just hold steady right where you are and then just get to lap 4; lap 4 will be the gut check just get yourself there feeling the same way you do right now.


Segment Duration (min:sec) Distance (miles) Ave Power (Watts) Normal Power (Watts) Max Power (Watts) Ave HR Ave Cad Ave Speed
5th 5k 6:48 3.1 211 209 352 169 93 27.4
6th 5k 8:44 3.1 221 219 331 169 93 21.3


Happily, lap 3 goes darn near exactly the same as lap 2, looking at the data in hindsight (I didn’t know this level of detail while racing), I am pretty happy to see that I nailed lap 3 with that level of consistency when compared to lap 2.  Also looks like the wind conditions stabilized since nearly equal power into the wind yielded nearly equal speed/time.

As I was approaching the start of lap 4, here is what went through my brain:  This downwind section seems to just go right by so quickly and the RPE hasn’t been bad at 220 ish; just see if you can beat 220 or so and let it hurt a little bit, I was able to hold 227 all the while saying, I am going to turn myself inside-out going into the wind, so keep some in reserve; hurt a little, but don’t drop the hammer.

I made the turn and I went Star Trek; I am “given her all she’s got captain.”  This hurts.  It hurts bad, it is supposed to hurt bad and you can take a lot of pain for 8 minutes (in my mind on course I was saying it was 7.5 minutes, but oh well).


Segment Duration (min:sec) Distance (miles) Ave Power (Watts) Normal Power (Watts) Max Power (Watts) Ave HR Ave Cad Ave Speed
7th 5k 6:31 3.1 227 226 348 172 94 28.6
8th 5k 8:18 3.1 250 247 445 177 95 22.4



I crossed the line and didn’t pedal for about 1 mile, I just coasted until I could see straight again.

What do I take from this?  My FTP surely wasn’t 188, I was able to do 220 plus for 50 something minutes and then go 250 watts for the last 8, including a final 30 seconds up around 325 or so.  Good news: FTP is higher; Bad news: every interval from here forward will be harder!

Other takeaways, for an event like this (mostly flat 40k TT, or mostly flat triathlon course of any distance), you really only need 3 numbers on your computer race screen. 1 – “3 second power”, this should be the big number on the screen.  It represents what you are doing right now and what you can control right now.  2 – “30 second power.”  This tells you what you have been doing and where you are trending, coming out of a turn, you look down and 30 second power is 425, you are hammering too hard trying  to get back up to speed (for instance), 3 – “average ride power” (including zeros), this is what those first two numbers are trying to combine to produce over the course of the day.

My opinion on this event, I was overly conservative early on, had I paced it right, I think that there is no way I would have been able to jump up 30 extra watts for 8 minutes at the end.  Ideally, I would have vomited on the line the minute I finished and that would have been enough to have maintained my average with absolutely nothing else left in the tank.  I have 2 more of these on the calendar and  vomit at the line will be the goal for the next two.

Coach Jimbo


2018-03-14T01:44:07+00:00 March 13th, 2018|Uncategorized|Comments Off on Big Data