TTs - How do you race with power?

Hi all

I’ve just completed my first proper season of TTing and achieved all my goals with the help of TR :slight_smile:

However, I may have taken riding to power a little too literally. I’ve been sticking to power values identified through TR in the fear that I would ‘blow up’ if I exceeded them. I was making small time improvements until one week where I forgot my head unit and rode on feel… I knocked off 45 seconds from my 10 mile PB!

My question is at what stage do you ignore the numbers and trust your legs? Do you have power thresholds you avoid breaking (e.g. 130%), or ride the first X% of the race below FTP?.. I have a feeling I’ve been riding within myself due to an obsession with the numbers.



This year was also my first proper season of TTing (also achieved all my goals!); also my first season using power.

I practiced TTs on feel, PM only, and PM/feel combo. The combo package worked best for me for a couple of reasons: 1) I’ve been around a long time and know my body, and 2) I’m not totally accurate yet at controlling power targets (TR is helping). I found that the PM was more helpful on flat courses than rolling courses.

As for ignoring the numbers and just trusting your legs…maybe not a good idea if you want to get better – “your legs” are a pretty subjective metric. Then again, no harm in doing a few TTs just on feel so you know what you can and cannot do. Keep the PM in your jersey pocket or tape over the screen so you can’t look at it until you’ve finished the course, then compare the numbers


Hey there Dezza!

I think you would find episodes 163 and 164 of the podcast very interesting and helpful. These are the episodes leading up to and recapping the 40k TT challenge. In these, information about preparing for a TT and pacing for a TT is discussed. You can check these out here:

Also, in episode 142, we discuss training using RPE. You can definitely apply these concepts of training with RPE to racing as well. Here’s a direct link to where this discussion takes place:

As for a specific answer on when to not look at the numbers, I’m going to leave this to the experienced TTers in this group and maybe @Nate, @Jonathan, or @chad will chime in on when they just ride by
how their legs feel in a TT.



I use power as a rough guide during a TT, particularly as I start in order not to go out too hard and blow up. For longer races, which was a first this year for me (50&100 miles) I had a power value inmind based on my power duration curve, I rode at that for the first quarter and then adjusted it based on how I was feeling. For 10 mile TT, I now ride them flat out and tend to ignore power, as I have found that when I stick to power for those I end up with a bit left in the legs at the end and feel like I could’ve done better.

I use power constantly during a TT. I plan out my route based on how much above and below I want to target my effort against my FTP, ie more on climbs, less on decents.

Do you have your TT bike on the trainer?

Thanks all for your replies. Food for thought!

I heard Chris Boardman talk about pacing during the recent worlds TT. He said keep asking yourself “can I sustain this power?”, if the answer is “yes”, keep pushing harder, if the answer is “no” then you’ve probably burned too many matches. If the answer is “maybe” then you’re good.

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Yes, always. I also powermatch my Kickr and P2M so im using the same kit inside and out.

Hey @Dezza, you’ve already gotten plenty of good advice (and Boardman’s comment is gold), but I’ll add my take on the issue which is quite simple: every metric only serves to inform our perception. So the numbers and the data are extremely useful when it comes to cultivating an understanding of what going all-out feels like, what all-day pace feels like, what a hard but repeatable couple-minute effort feels like and what it feels like when that same couple of minutes is too hard to readily bounce back from.

And, of course, the data is extremely useful when structuring workouts and eking the most from your training as opposed to flying blind until you crack or end up missing the intent of a specific type of workout aimed at a specific performance adaptation; super useful when tracking improvement (or decreases) in fitness too since these objective measures are the very things that allow us to manage our training in measurable, reliable ways.

But allowing the numbers to govern your effort in a race is tricky stuff. Sometimes it can be the difference between pacing effectively and overdoing it early on, it can tell you whether certain scenarios are realistic or out of the question, and it can help you gauge when to eat based on energy expenditure in longer events, things like that.

But all of these have to be weighed against how you feel regardless of what the numbers say, because sometimes you just don’t have it, sometimes you’re verging on breaking down barriers and ‘leveling up’, and in both cases, allowing the numbers to be the only and final word can be counterproductive.

By all means, train by the numbers, maybe even race by them in some instances, but always be building your performance self-knowledge and strengthening the link between what the metrics tell you and how you feel, what you can do regardless of what the data says.


Being new to TTing, I am using BestBikeSplit Connect IQ app on my Garmin and follow the power targets as they pop up. It works out great as I always feel I pushed to my max. Hopefully with experience I can sprinkle in my own RPE during a TT race, but right now, if I relied on RPE only, I wouldn’t finish a race.

Many thanks Coach @chad. Makes total sense, looks like I need to invest more time and effort on understanding feelings rather than my wahoo (proper jedi stuff). Cheers!

I have always struggled with this. I can hold position, training or racing, on the road for 40 min without a problem. On the trainer, I am lucky if I can hold it for 10min before my arms start to hurt.

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For a slightly different perspective…

I played with the Xert segment hunter during my free trial recently and while it clearly has issues with anything hilly it created some very interesting results for me on flatter medium duration segments. By trusting the numbers it got me to push far harder through the segments than I would have thought possible otherwise and gave a breakthroughs. It works for up to an hour and has a TT mode.

I would like more time to play with it but just didn’t find enough value in the Xert platform to justify the monthly sub. Ild also like to do some comparisons with best bike split which I suspect might do a better job at pacing over longer distances but it’s hard to know if it would push you as hard as Xert would.

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Try raising the front axle 1-2" [25-50mm] higher than the rear axle. This can help shift weight off the hands and arms.

It’s an effort to offset the lack of wind resistance pushing your body back when you ride outside.


a small piece of plywood does the trick…

So true. We still have to interpret those numbers by bouncing them off of how we feel…right? So, RPE seems like the common denominator.


Race with power rather than to power I find. I have power displayed on my head unit but rely mainly on RPE regardless of distance.

If you are too rigid about hitting a specific number you can miss a day when you could have done more but far more likely is that you (if you are like me!) aim to equal the best numbers you’ve achieved in the past and by definition theses are outliers rather than the norm. And that’s not taking account the day to day differences in PM calibration which depending on which one you use can be +/-2%.

I raced a TT pretty much twice per week during the race season this year, either a midweek 10, 15 or 25 and a longer TT at the weekend and some days are just better than others. Go in to the race with a ballpark figure in mind knowing that it is just that and give it your best shot.

Like you ironically one of my better rides this year when I set a 100 mile PB occurred when the battery in my PM died in the car driving up to the race so have no power data and have to rely exclusively on RPE and speed.

I applied the same in a Ironman I raced at the weekend on the run. I had a target time in mind my decided to run purely to RPE until at least halfway when I allowed myself a first look at my watch. I went though that point probably far faster than if I had been rigidly running to pace and while I lost time in the second half I by no means exploded and ran well inside my target time and had a great race.

Power is a great tool but it is just that, a tool and the more you TT the more you can trust what your legs are telling you.

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Used as a leash to save going out too hard, you’re not going to suddenly wake up on any given day with a magical FTP boost +30/40w might feel great by RPE but soon enough it won’t! Adrenaline and excitement wears off quickly enough (5 mins) by which point you can settle in.

Great tool to reign it in on the climbs and equally to continue pushing on when you feel like letting up.

Never thought of it in those terms, but it makes sense.

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I came up with it about 5 years ago. Did lots of training for the first time inside. Hands went numb in 15 mins when I was fine outside on the same exact setup.

Thought about it a bunch and came up with the wind resistance theory. I tried the higher front to compensate and it works. So I share that anytime people mention the same issue.