Monday, June 29, 2009

TT Pacing Research

One of my peculiar habits is that almost every day I read from a stack of research abstracts looking for interesting stuff that I might be able to use in training. This morning I found one on a topic near and dear to my heart. I’m sure you can guess what it is: Pacing in cycling time trials. This research would also apply to the bike leg in a triathlon, I believe.

In this study Mattern and colleagues at the University of New Hampshire examined the effect of different pacing strategies in the first 4 minutes of a 20km time trial (Mattern, et al. 2001. Impact of Starting Strategy on Cycling Performance. Int J Sports Med 22(5): 350-5). The 13 subjects were experienced and competitive road cyclists (average VO2max was 71.7). They did three time trials at this distance over several days. The first was done at a self-selected pace for the first 4 minutes and for the remaining times. We’ll call this self-selected trial ‘SS.’

A few days later the same riders repeated the 20km TT. And a few days after that they rode the third one. On these latter two occasions they were told to ride for the first 4 minutes at a power output that was either 15% less than in SS (‘-15’) or 15% greater (‘+15’). These two were done in random order. In both instances after the first 4 minutes they could ride at whatever power and effort they wanted trying to produce the fastest times possible.

On average, the fastest times came from the -15 trial. Power was significantly higher after the first 4 minutes in this trial compared with SS and +15. There were no differences after the first 4 minutes between the 3 trials in terms of heart rates or ratings of perceived exertion. Everbody still suffered later in each of the trials, but in -15 the suffering started later.

Is holding back 15% for 4 minutes the perfect strategy for you? Maybe. Maybe not. But the take-home message here is that you will probably have your best times by holding back a little early in the race.

Although this study did not address the start strategy for running events, I expect the results would be similar for age grouper runners in a mass start race. That may not be the case for the elite runners in such a race due to the need to factor in drafting into the wind (they’re moving pretty fast) and the pacing strategies of the other elites.

The -15 trial is basically the strategy I strongly suggest to the athletes I coach. I’ve found that the only way to get them to do this in a race is to repeatedly rehearse it in training with graphic feedback so they know how they did. Even then it can be very difficult to hold back the first few minutes of competition. Patience and confidence are the keys. If you are impatient or lack confidence in your ability the tendency is to start much too fast (+15% or even more) and then limp home the final fourth of the race. I’m afraid this is what nearly all athletes do.

Realize that you can go too slowly at first, also. The best way to get your start pace figured out is to to try it several times in training and in races. The latter is the more important. Give the -15%-for-4-minutes strategy a try in your next B- or C-priority race and let me know how it worked for you.


At June 29, 2009 4:34 PM , Blogger Marcos Apene do Amaral-TriPhiloSophia said...

Just completed the A race of the season. 1/2 Im where proper pacing is even more important. Did that "minus everything" till the second half of the 21km and bingo! Personal best with low perceived exertion for the most part od the race and guess what, patience and confidenca are paramount as the most age-groupers always hammer in front of you but later you got the return and as the start fading you keep going on and gaining lots of time on them! And the more technical and dificult the race goes, the more important this strategy seems to be true!
Keep that wisdom and experience guiding us over the world wide web, cheers, thanks, from a wanna be "guiea pig" of your training methods, Marcos!

At June 29, 2009 4:54 PM , Blogger perrygeo said...

I race cross-country MTB and by far my best races come when I hold myself back at the start. The problem is that most courses have significant portions of singletrack which make passing and keeping track of your competitors difficult if you get stuck behind slower riders. As a result, there is a mad sprint for position to start each race, similar to the the "+15% for 4 minutes" situation.

Assuming this initial mad dash is inevitable, is there a proper strategy to recover from this to make sure your legs feel fresh in 2 hrs? Maybe take the next 4 minutes at -15%?

At June 29, 2009 7:33 PM , Blogger Joe Friel said...

perrygeo--Yes, MTB is a bit different due to the frenetic start required some times to get a position on the single track. I don't think there is a single answer to that conundrum other than to recover when you finally get a chance. this will often be determined by the terrain and trail.

At June 29, 2009 11:05 PM , Anonymous hans said...

Shouldn't warming up play a part in this? If you spend 4 minutes before the start of the race, presumably you could then use race pace from the start.

At June 30, 2009 6:12 AM , Blogger Joe Friel said...

Hi Hans--Good question. But even with warm up riders tend to ride well above 'race pace' (i.e., +15). If indeed they started at race pace (or average power for entire race) they would, in effect, be riding in the neighborhood of -15% relative to what they normally do in self-selected trial. I believe the purpose of the -15% is not to warm up, but rather to prevent the build up of acid in the muscles which eventually decreases power.

At June 30, 2009 6:56 AM , Blogger usrnull said...

Would this strategy scale down to shorter events, say, for a 3/4k pursuit event at the track?

Obviously in the space of four minutes the races are all but over, but your instinct is do drop the hammer, more or less, from the gun, though experienced racers say "don't start out too fast." The question is, how fast is too fast?

Is there a similar strategy to use, say 45 seconds instead of 30 to reach optimal speed, if it results in a slightly higher average speed?

At June 30, 2009 7:26 AM , Blogger Joe Friel said...

usrnull--Good question. I haven't really looked into this issue but have come a cross a couple of studies. If my memory serves me they found that in such short events achieving high power early and maintaining it as long as possible is more effective than holding back at the start. These are highly anaerobic events done at about power at VO2max. Achieving that power or slightly more asap seems to be the way to go.

At June 30, 2009 7:02 PM , Blogger Patrick said...

Thanks for discussing this thought provoking article. I plan to test it on a hill climb where I do some TT & FTP training. The climb takes nearly 25 minutes and averages around 6% grade. One question: The first km is a little steeper than the average gradient. Would you still reduce in initial wattage 15% or as suggested in the mountain bike comments above reduce the wattage after the gradient evens out?

At July 1, 2009 8:23 AM , Blogger Joe Friel said...

Parick--the whole idea is to restrain yourself in the first few minutes of the event so that you don't overwhelm the body with acid and then have to deal with it the remainder of the race.

At July 1, 2009 10:10 AM , Blogger Tim said...

Joe -
Does the concept hold true for events where the pace is well below LT or FTP? Lets say a HIM?

If I take 4' for 20km race (roughly 30' for me), that is 13%. I'm about a 2h40m HIM rider so 13% is ~20'. A typical HIM pace is 80% FTP, and if I gross that down by 15% then I am at 68%. Would you recommend riding the first ~20' @ ~68% FTP? Does either this research or your observations support this strategy?


At July 1, 2009 11:32 AM , Blogger Joe Friel said...

Tim--The tendency at eveery distance is to go out much too hard in the beginning. I always stand at about the 1 mile point at IM Hawaii on a slight hill. It's amazing how many people are anaerobic at this point with 111 miles to go. I have everyone I coach hold back for some portion of the early part of the race regardless of distance. Riduculously easy. Can't tell you what percentage. Depends on how long you will be out there. The percentage for a 2:15 bike leg will be a lot higher than for a 3;15 although both athletes are working at appropiate perceived exertions.

At July 1, 2009 2:06 PM , Blogger Tim said...

Is the holding back of "some portion" in the early going on the bike primarily a function of the distance or both the distance and the athlete? Do you have a 2:15 and 3:15 hold back for the same length of time or the same proportion of time?

I would guess it'd be by % of time. Maybe around 10%?

At July 1, 2009 4:33 PM , Blogger Joe Friel said...

Hi Tim--I don't have any hard and fast rules on this. It depends on the athlete and the course. Terrain often determines the hold back period. For example, in Kona for the IM I usually have them hold back while in town and not start really riding until they start out of town.

At July 4, 2009 3:53 AM , Blogger Robin Smith said...

Using a pacing strategy of -10% for the first 3 minutes, here are my results from a 10 mile TT on Thursday evening. Can anyone tell from this if I went out too hard or too easy?

Ave W/qtr : 272 288 294 299
Ave HR/qtr : 152 168 168 170
w/HR : 1.79 1.71 1.75 1.76

The overall power curve was much smoother than normal for the first 3 qtrs, but much less smooth for the final qtr

Cadence used was deliberately lower (97) than I normally use (100) but this felt fine and may have helped a smoother power delivery than normal

My fitness condition was still a little tired from an intense MTB event 4 days earlier plus some interim CTL training

At July 4, 2009 4:14 AM , Blogger Joe Friel said...

Robin--The only way to know what such pacing would mean is to compare your performances with previous ones in which you didn't pace yourself that way. Or perhaps how you did relative to known competitors.

At July 4, 2009 5:05 AM , Blogger Robin Smith said...

Joe, then pacing strategy seems not to work for me. It seems to have worked best when I tried to hold the SS throughout. See below. I'll continue with it though as this week I have been tired and have just finished a race period.

Latest (above)

Overall ave power 288.3
Ave W/qtr : 272 288 294 299
Ave HR/qtr : 152 168 168 170
HR/w : .56 .58 .57 .57


(was holding back just a little at start)

Overall ave power 292.4
Ave W/qtr : 288 294 290 298
Ave HR/qtr : 158 168 169 170
HR/w : .55 .57 .58 .57

Best recent

(was trying to hold SS throughout)

Overall ave power 296.5
Ave W/qtr : 307 291 294 295
Ave HR/qtr : 163 169 170 172
HR/w : .53 .58 .58 .58

At July 4, 2009 12:10 PM , Anonymous Anonymous said...

Mr. Friel
Not really a TT pacing question but more about building up for my goal 40K TT race in the beginning of August.

I have done quite a few 20km time trials and my times are around 28:30 to 29 min. The course that the 20km is held is hilly but the 40km race is a completely flat course.

In this month there are two 40km time trials being held that I can relate to. One is next weekend and the other one will be July 24th. My goal race is August 8.

Would you recommend using the two time trials in July as preparation of the goal race or is that over doing it and would I recover to the point that it will not affect my goal event performance?

At July 4, 2009 2:04 PM , Blogger Joe Friel said...

anon--Assuming you are in good shape you should have no trouble recovering from those races.

At July 24, 2009 6:02 PM , Blogger Getfitwithsteve said...

Hey Joel. I read your book The Cyclist Training Bible while i was on vacation in New York this summer. I must say, i was very hesitant to your information because I am one of those hammer on the front cat 3 crit guys. Over the past month since i have been back i have noticed a major difference in recovery by sitting in on group rides, cutting my training hours down and resting more. Wow. Who would have known. Either way, I am doing a 40k TT on Sunday. Gonna try the hold back effort and see what happens. I am shooting for 60min. Will let you know the results.


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