Monday, May 4, 2009

More on Time Trial Pacing

Here you can see a chart from the Rabbit Mountain Time Trial held yesterday near Boulder, Colo. The chart is from a pro triathlete. It again illustrates my point that when going uphill you need to increase the power output. He started just a bit fast, which is common, but within three minutes settled into a work rate which he held quite steadily for the remainder of the race, except when going up hills. This course has a rather long, steep climb to the finish and you can see here that his speed is the lowest of the race and his power the highest. This chart is a good example of how to pace yourself in a non-drafting, steady-state event.


At May 4, 2009 7:43 AM , Blogger Phil #398 said...

Joe - this brings up a good question about the difference between power output on flats and uphill. Was this athelete's RPE steady for the entire race? Perhaps.
In my case, I find that my threshold tests tend to be 30 watts higher when I'm using a long steady climb, than when I'm doing the test on the flats. Same RPE and heart rate. I can't see the HR on this athlete's chart. This brings into question which is the correct test to use (flat vs. uphill), and why there is such a difference. Other friends who race report similar although perhaps not so drastic findings. Thoughts?

At May 4, 2009 10:07 AM , Blogger Joe Friel said...

Phil--Good questions. RPE is always rising in a TT if it is paced correctly. His HR (not shown on the blog post) reflects this. It dipped only on downhills and otherwise slowly and slightly climbed.

Some people seem to have better economy on hills. Others on flats. I often have the athletes I coach use a gradual (2-3%), steady grade for CP30 tests. But I also like to see what they do on flats.

At May 4, 2009 2:48 PM , Blogger Don said...

How do we define "a little bit higher power output on the climbs" your example looks ruffly at 15% increase. Should we hold a percentage or would it be a variable based on long climbs, short climbs, steep climbs, etc.?

At May 4, 2009 3:35 PM , Blogger Joe Friel said...

don--Good question. It will vary due to gradient, length of race, fatigue and wind. It's an art. Not a science. Too many variables to put an exact number on it. But probably 5-20% increase on up side and 5-100% decrease on downside.

At May 5, 2009 2:12 AM , Blogger David said...

For another view on "perfect" TT pacing, have a look at the model developed here which Alex Simmons wrote:

I came across this initially from this blog post:

At May 5, 2009 7:15 AM , Blogger Wess said...

Joe -

I like reading this ("when going uphill you need to increase the power output").
I was on a training ride Saturday using my PT (new for me) and was coached to hold watts constant (75-85% FTP for the wkout) up the hill then again down the hill. My speed dropped so far trying to hold those watts that it was actually hard to keep from falling over. Others were pulling up the hill and left me in the dust.
Per the coaching I was supposed to "catch and pass them" after the downhill as they would suffer from lactic acid overload at some point in the ride. So I followed the plan and lost contact with them (only to reconnect when they waited up miles later) - I just couldn't close the gap with the constant watts rule.
So on the second lap (a 20 mile loop) I put my PT on my pocket and rode only by RPE. Wanted to ride the hill as I felt I could, crest it and continue for the rest of the ride. Without the PT to consult at the time I know I raised my power output on that climb. For the rest of the ride I managed to hold a steady pace and felt as strong as the first loop - except this time I was out front with one other guy.
Do I dump my PT?? Kidding. I enjoy it so far - but I am glad to read you thoughts on increasing watts a few % points up hill and decreasing (for rest) down hill.


At May 8, 2009 2:02 PM , Anonymous Anonymous said...

Constant watts is nonsense.

If you do the math, the optimum power profile is something like +/- 25% either side of the average, driven by the gradient... see for example

At June 4, 2009 5:15 AM , Blogger Matt Perry said...

When you go Up-Hill you engage a different set of muscles. I find that I use more Gludes and Back and generally recruit more muscle in the uphill effort then on the flat. Due to this I assume my FTP is about 30+ watts(approx 110% of my flat FTP) higher when I climb. For those who posted about keeping there power output in range on climbs you might want to consider adjusting you FTP based on what you potential is when climbing. I've had a PT for about 8 months now and I use it to track my wattage and I can say that the data seems to back the assumption that different/more muscle is recruited for climbing.

At June 18, 2009 7:45 AM , Anonymous Anonymous said...

@wess: your coach told you to do constant watts to train an energy level, not to hang onto the back of a group or to win a time trial. When my coach wants me to do constant power (which he does for very good reasons), I simply don't go on group rides. Joe isn't telling you to go harder on hills in general (or to ignore your coach) but to lift your power on uphills during a time trial. When you went out front with the one other guy, you completely abandoned the workout you were supposed to do (base) in favor of a mixed pace race ride, with VO2, tempo and lots of recovery thrown in. Perhaps most simply put, it's a matter of what your objective is for a ride - not what makes you perform best every day.

@Matt Perry: last I knew, the research showed little or no difference in muscle recruitment on climbs as opposed to flats. I go back and forth on it, but ultimately I bet there isn't a 10% difference in FTP on climbs as opposed to flats. Especially as we haven't specified the grade of the hill, since surely a 20% grade would recruit much more than a 10% or a 5% etc. It's just "easier" to push with slow twitch muscle when there's resistance (not fast twitch - do a sprint power test uphill and downhill and compare them) - if you concentrate on the flats you can produce the same power outputs as on a hill, RPE is just slightly higher.

If you really want to know your FTP, get it tested in a lab. If you've spent $1k on a PT it only makes sense to spend $80 every few months on a finger stick test to know how to use it.


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