How to Pace a 10 Mile Time Trial, What the Pacing Research Found

James. This is the WattPlan Podcast and I'm James. Two kids, a day job, WattPlan to build in the gaps, the odd podium when the fast lads stay home, and a reading habit that's mostly sports science. Tonight it's the club 10. Ten miles, flat out, every Tuesday evening from April. How hard do you go, and do you go even or do you hit the drags? Lyra, our AI research voice, has been through the pacing studies, and all of them are linked in the show notes.

Lyra. Even. For a ten mile time trial the answer the research keeps giving is even power on the flat, a few percent more into the wind and up the drags, and a first couple of minutes at your target rather than above it. The thing riders get wrong is the start, and the second thing is surging for no reason. Everything else is detail.

James. Even. Right. But a 10 is twenty-odd minutes. Surely you can go out hard and hang on?

Lyra. That's the question the review answered. Greg Atkinson and colleagues went through the pacing research in Sports Medicine in 2007 and sorted it by how long the race lasts. Two minutes or under, go out as hard as you can, because the time you save at the start is worth more than what fatigue costs you at the end. Ten minutes or under, a harder start than the rest. Over ten minutes, in stable conditions, even is fastest. Every ten mile time trial is over ten minutes, the record included, so you're in the even group. [1]

James. Fine, but everyone I know goes out too hard. Me included.

Lyra. The review says exactly that. Experienced cyclists tend to start longer time trials above the work rate that would give them their best time, and the authors didn't know whether coaching could fix it. So the first mile goes at a hundred and ten percent because the legs feel wonderful, and the other nine pay for it. If you take one thing from this episode, it's that the first two minutes should feel too easy.

James. What is the target, then? For a twenty five minute 10, what percent of FTP?

Lyra. A little above FTP. FTP is the power you can hold for about an hour, and most riders set it from a twenty minute test, taking ninety five percent of their twenty minute best. Turn that round and a flat out twenty minutes is about a hundred and five percent of FTP. A thirty minute ride sits much closer to FTP itself. So your average for a 10 is FTP plus a margin, and the margin shrinks the longer you'll be out.

James. So even's the template. Where does varied power come in? Because I've read you should hit the hills.

Lyra. You should, and the field trial is the nice one. Phil Cangley, Louis Passfield and colleagues took twenty experienced cyclists to a four kilometre undulating course and had each of them ride it four times, published in the International Journal of Sports Medicine in 2011. Two rides at constant power, two with power lifted on the rises and eased on the drops. The varied rides were twelve seconds faster, about three percent, and that held up statistically. The riders also found constant power hard to hold on an undulating road. [2]

James. Three percent for the same legs. On a twenty five minute 10 that's, what, forty seconds?

Lyra. About that, if your course has rises in it. The reason is physics rather than physiology. Going uphill nearly all your power goes into lifting you and the bike, so each extra watt is extra speed. On the flat at forty five kilometres an hour most of your power goes into pushing air out of the way, and an extra watt buys almost nothing. So a watt spent on the drag is worth more than the same watt spent on the flat, and a watt spent on the descent is worth least of all.

James. Right. So I should be smashing the drags and coasting the other side?

Lyra. Not smashing. A few percent. The review puts what sub-elite riders manage at about five percent either side of their average over time trials of twenty five to sixty minutes, and the models that predict the savings used ten. Lift a little on the drag and into the headwind, ease a little on the way down and with the wind behind. The total work is the same. You've moved it to where it buys time.

James. And the wind. Most 10s are out and back on a dual carriageway. Do I treat the headwind leg like a hill?

Lyra. Yes. The review's rule is to raise your work rate into a headwind and uphill, and lower it with a tailwind and downhill, which keeps your speed steadier and your total time shorter. So on an out and back, go a few percent above target into the wind and come home a few percent below it. And the turn is the one place a short surge pays, because you're accelerating from low speed where the air costs almost nothing. A few seconds, then settle.

James. Here's my worry, though. If I'm allowed to vary, I'll vary all over the place. Does that really cost me?

Lyra. It does, and there's a study that shows how much. Marc Wells and Simon Marwood modelled a rider over forty kilometre hilly courses in the European Journal of Sport Science in 2016, and compared swings in power that followed the gradient with swings that didn't. The ones that followed the road saved minutes. The same sized swings made regardless of the road, every kilometre or so, cost time, and the bigger the swing and the steeper the course, the more it cost. [4]

James. So surging to pass someone is me paying twice.

Lyra. It's you paying to feel good for ten seconds. The watts you put in above target on the flat buy almost no speed, and you've then got to recover them. Pass people by riding your number. If they come back to you on the drag, that's the drag doing the work.

James. What's a good time, then? Because I know what people ask.

Lyra. The British competition record for ten miles is sixteen minutes thirty five for men and eighteen thirty six for women, both set in 2016 on the same course, which tells you how much the course matters. For the rest of us, twenty minutes is thirty miles an hour, twenty five is twenty four and thirty is twenty. And because the air takes most of your power at those speeds, a minute off a twenty five costs a lot more than four percent more power. That's why position and pacing move a 10 so much.

James. Let's make it practical. If you're new to this and it's your first club 10?

Lyra. If you're new to this, ride the first two minutes at an effort that feels too easy, hold it, and save the hard bit for the last mile. You'll pass people who went off like a rocket. Don't worry about the drags yet. An even ride you finish strongly beats a clever one you blow up on.

James. And if you train with power?

Lyra. If you train with power, get a fresh FTP in the four weeks before and set your target at FTP plus a small margin that fits your expected time. Then learn the course. Find the drags and the turn, and check which leg will have the headwind that evening. Plan a few percent above target there and a few percent below on the way back. And look at your power at the one minute mark. That's the number that tells you whether you've already blown it.

James. And if you race?

Lyra. If you race, the gains are at the edges. Your even pace is settled, so the time is in the start, the turn and the wind leg. Practise holding target in your time trial position with a threshold session a week in the weeks before, so the position doesn't cost you watts on the night. That's where the seconds are.

James. Where does WattPlan come in? Because I'm not pacing from a spreadsheet at half seven on a Tuesday.

Lyra. The pacing on the night is yours. WattPlan does the week and the course. Add the 10 to your plan as a race and it treats that day as the week's hard session, puts easy openers the day before and recovery the day after, and counts the race in the week's Load. You can tell the Coach the date and it adds the race for you. The threshold workouts in the library are the sessions that build the power a 10 is ridden at.

James. And the course?

Lyra. Upload the route to the free pacing calculator on the website and it gives you the power and time for every climb for your FTP and weight, and the file never leaves your browser. In the app, Route analysis is part of Premium. With a critical power and W prime on your profile it spends your W prime where the road is steep rather than evenly, and writes a pacing file for your bike computer.

James. And what doesn't the research know?

Lyra. Nobody has run a pacing trial over ten miles. The field trial was four kilometres with twenty riders, and the bigger numbers come from models of a seventy kilo rider. How much a particular rider can vary power without paying for it later isn't settled, and that five percent is an observation of what sub-elite riders do, not a tested limit. Nothing tests the turn. What's settled is the shape.

James. So, even on the flat, a bit more into the wind and up the drags, and the first two minutes too easy on purpose.

Lyra. The first two minutes are where you win a 10, and they're the two where it's hardest to go slowly enough.

Lyra. The full article and every study we mentioned are on the WattPlan blog, linked in the show notes. And if you've enjoyed this, follow the WattPlan Podcast wherever you're listening, so you don't miss the next one.

James. And if you want a plan built around the time you've actually got, get WattPlan on the App Store or Google Play. Thanks for listening.

Voices produced with ElevenLabs. James's voice is a clone of his own, Lyra is an AI voice, and James reviews every episode.