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What does it take to ride the Tour of Flanders: The difference between pros and amateurs

Nick Busca
5 Apr 2018

What's the difference between a domestique in the WorldTour race and an amateur riding the sportive? We investigated

The Tour of Flanders is always one of the hardest races of the calendar, but what does it really take in terms of physiological demands? A few riders – including the winner of the 2018 race Niki Terpstra – have already shared their efforts on Strava, but in most cases very important metrics such as heart rate and power output are hidden.

Cyclist, on the other hand, had the rare opportunity to look into two Bora-Hansgrohe riders' physiological data from the men's race. Because Bora agreed to release the power outputs, the cyclists' identities were kept secret.

And no, Peter Sagan is not one of the riders; they are from two of his loyal teammates and we will call the riders Dom1 and Dom2.

Frenetic start

The race started pretty fast and furious, with the first hour covered at an average speed of 46 km/h and several attempts from many riders to break away early in the day.

Eventually a small group succeeded after 70 km, but no Bora riders were in it, so it meant a hard day at the back for Sagan’s team to close the gap.

The race continued with crashes and a hard tempo set by the teams in the main peloton.

Dom1 (69kg weight) was one of Sagan’s first men to work for his leader. He was active in the first part of the race, where the battle was mainly to keep the positions before the cobbled sections and not let the breakaway go too far upo the road.

His numbers revealed an average power of 255 watts (3.69 watts/kg) over the course of 6 hours and 35 minutes of the whole race.

However, his NP (normalised power) gives a better idea of the kind of effort he put in during De Ronde. As a metric calculated by an algorithm on TrainingPeaks, NP takes into account the difference between a steady or a fluctuating workout.

Because in terms of physical stress on the body, one thing is to ride at a steady average power of 255 watts on a flat and easy road for example, and it is another to ride the Flanders route with lots of hills and parts where the power goes up and down.

So, Dom1’s NP was in fact much higher than his average and he finished the ride with a total of 297 watts of NP (4.3 watts/kg), with a mind blowing peak of 1,104 watts on the Paterberg (the second time up).

At the end of his ride, that power effort combined with an average heart rate of 151bpm and a max of 183bpm (also on the Paterberg) with a total expenditure of 5,978kj.

When the big chunk of the riders slipped away and the tempo increased once more, the race started to enter its climax. And with 50km to go, six riders moved into the front on the Koppenberg, while the big favourites started to set a higher pace at the back.

Dom2 was one of the last men to leave the World Champion’s side and his effort to keep him in the front for the final part of the race was really hard.

Dom2 averaged 286 watts for the whole ride, and with a weight of 82kg, that gives an average of 3.48 W/kg. But when you look at his NP, the real effort gives a different account, with Dom2 finishing the race with 338 watts of NP (4.12 W/kg) and a maximum power – also reached on the Paterberg – of 1,150 watts for a total kj consumption of 6,715.

We also have more data of his effort recorded on two of the most famous climbs of the race, the Oude Kwaremont and the Paterberg, which were ridden three times and twice respectively during the 2018 edition of De Ronde.

On the second time that the Kwaremont was tackled, Dom2 averaged 440 watts output for a total of 6 minutes, and in the steeper but shorter Paterberg he cranked out 580 watts for 1 minute and 30 seconds.

As he didn’t wear a heart rate monitor, these data are unfortunately missing.

Dom2's power percentages

52%: 0-300 w
22%: 300-400 w
8%: 400-470 w
11%: 470-570 w
7%: rest

'As coach I am always happy if I get as much data as possible for the analysis, but of course the athlete should feel comfortable with it,' explains Dan Lorang, one of the three Bora-Hansgrohe coaches along with Patxi Vila and Helmut Dollinger (Head of Performance is Lars Teutenberg).

At the end of this year’s Flanders, Bora didn’t quite match its goals and “only” finished with Sagan in 6th, at 25 seconds behind Terpstra. Although the performance of the team was quite strong, Sagan was left alone a bit too early.

'We are not completely satisfied [with the performance],' says Lorang. 'We hoped that the guys could have stayed longer with Peter to be more flexible [with the tactic] later.

'Peter was isolated too early and he was alone against Quick-Step. Then it becomes very difficult for him to do everything on his own and the other guys he ends up in the group with are not really willing to help.'

Lorang also said that the overall performance was not the one they were expecting both because some riders didn’t have the best legs that day and also because the race started very hard.

Sportive rider vs professional cyclist

But how do the numbers of Dom1 and Dom2 compare to the data of 'normal human'? If you’re familiar with racing and training performances, you might have already understood that – at least in these cases – long gone are the days where riders were showing 7+ watts/kg of power output (read: Lance Arsmstrong).

But to give you a better idea of how strong pro cyclists are and how far they are from recreational riders, I’ll compare their data with mine.

No, of course I didn’t ride with the pros on Sunday, but I took part in 'We Ride Flanders' – the sportive that is held the day before the pro race.

I rode the sportive with three friends and we signed up for the long course, which was 232km (the pro race was 264) and included 16 climbs – such as the iconic Muur van Geraardsbergen, the Koppenberg, the Oude Kwaremont and the Paterberg.

Thank God we only climbed these monsters once, and not twice or three times like the pros. But similarly to the pro race - which also started in Antwerp and finished in Oudenaarde like ours - the cobbles and hilly sections started after a 100km 'warm up' on flat Flemish roads.

My three friends and I finished the ride in 9 hours and 3 minutes, and this was only our total riding time. We stopped at all the feed stations except the last one, where we opted for a bar and a coffee instead.

So yeah, it wasn’t really a race-pace day for us, but it was still tough.

My average power output was 148 watts (haha!), so a not greatly impressive 2.05 watts/kg for the whole ride (my weight was 72kg the day before).

The NP was on the other side 184 W (2.5 w/kg) and the maximum was 1,070w, which is probably the only number I am actually proud of.

It may be an error of the power meter or the bike computer, but I’m using the same ones as Bora, so I’ll take that.

To make it more understandable, yes, I spent most of the time in the front of my little group (those wheel suckers!), but my heart rate was most of the time in Zone 1 (recovery) and Zone 2 (aerobic) with an average heart rate of 115 bpm for the whole ride and a maximum of 173bpm on the Koppenberg (damn, that was hard!).

That is exactly where you want to stay for such long endurance events when you’re not racing. But in total I was still able to consume 4,584kj, which were replenished during the ride with four gels, four bars, four waffles, lots of salt biscuits, three bananas, half a sandwich with cheese and other unidentified calories, for a possible total intake of more than 6,000kj.

So, once again, even the Ronde van Vlandeeren ended up as a ride where you got heavier than when you started. But hey, it was epic!

Sportive photos: Sportograf