By the numbers: Just how easy was the Giro’s stage 6 snoozefest?

By the numbers: Just how easy was the Giro's stage 6 snoozefest?

It was one of the least exciting days of bike racing we’ve seen in recent years. Five long hours of the Giro d’Italia peloton rolling sedately north from Palmi to Scalea in what the riders seemed to declare an unofficial rest day.

But Thursday’s stage 6 of the Giro did get us thinking: just how easy was the stage really? Easy enough that amateur riders could have kept up?

First though, let’s set the scene with some Strava file titles and descriptions from those in the bunch.

Dries De Bondt called the stage a “coffeeless coffee ride”, Attila Valter called it a “sleeping day”, Richie Porte included a snail emoji in his ride title, and Alex Dowsett wrote “Dull. Then we sprunt for the line.” (Dowsett gets extra kudos for the great, intentional typo.)

But perhaps the most telling comments came from Mathieu van der Poel and Owain Doull. Van der Poel called it “maybe the easiest race I’ve ever done” while Doull was even more decisive: “Hands down the easiest race I’ve ever done. When it goes easy here it goes really easy.”

So what does “really easy” mean for WorldTour riders? Let’s take a look at the numbers.

Race organisers predicted the stage would be raced at somewhere between 42 and 46 km/h. Stage winner Arnaud Demaré crossed the line with an average speed of around 38 km/h, leading the bunch home half an hour later than the slowest predicted finishing time. A decent male amateur club racer wouldn’t have too much trouble averaging 38 km/h on a flat stage, in a Giro-sized bunch, for five hours.

But it’s when we look at riders’ “weighted average power” numbers on Strava that we get a real sense of how easy the stage was.

As defined by Strava, weighted average power is an estimate of a rider’s average power for an effort “if you rode at the exact same wattage the entire ride.” That is, the power a rider could have maintained for the same physiological cost had their power been perfectly constant throughout a ride (rather than full of spikes and troughs as all bike rides are).

Here are some weighted average power numbers from within the bunch:

Joe Dombrowski: 195 W
Alessandro Tonelli: 199 W
Alex Dowsett: 213 W
Alexander Cataford: 183 W
Attila Valter: 189 W
Ben Zwiehoff: 176 W
Davide Cimolai: 205 W
Dries De Bondt: 201 W
Lawson Craddock: 202 W
Thomas De Gendt: 239 W (note that De Gendt spent a good part of the day on the front, ‘chasing’ for Caleb Ewan)
Lilian Calmejane: 197 W
Mathieu van der Poel: 209 W

Let’s do some back-of-the-napkin calculations. Based on the small sample size above, you’re looking at an average of roughly 200 W for the average rider in the bunch. And with the average weight of a rider in this year’s Giro being 67.6 kg, that average rider had to produce somewhere in the vicinity of 3 W/kg for a touch over five hours to finish in the main peloton.

Again, roughly 3 W/kg for five hours is the sort of effort a decent amateur male racer is certainly capable of. For the best riders in the world, this is about as easy as WorldTour racing gets. (Note: It was a slightly tougher day for lone leader Diego Rosa who spent about 140 km off the front on his own, and averaged 240 W (3.7 W/kg) for the day. This will still probably be one of the easiest days he has all Giro.)

If we look at other stages in the Giro so far we can see how easy it was in the bunch on stage 6.

Let’s take Alex Dowsett for example. The Briton had a weighted average power of 213 W (2.84 W/kg) for the glacial stage 6. Compare that to the 294 W (3.9 W/kg) Dowsett needed for stage 5. Dowsett finished in the front group on both stages, and both stages ended with a bunch sprint (but stage 5 did have a decent climb in the middle).

Dowsett’s numbers on stage 4, to Mt. Etna, were even more telling. Dowsett described it as the “first proper Giro day, relentlessly on the pedals all day”. There his weighted average power was 302 W (4 W/kg), and that was to finish nearly half an hour behind the stage winner.

Stage 4 was a slightly harder affair.

Lilian Calmejane’s Strava files tell a similar story:

• Stage 6: 197 W (2.86 W/kg)
• Stage 5: 271 W (3.93 W/kg)
• Stage 4: 315 W (4.6 W/kg) – where he finished 15 minutes down.

And then there’s Mathieu van der Poel. Recall that on stage 6 of the Giro his weighted average power was 209 W (2.79 W/kg). On stage 1, which he won, Van der Poel put out 249 W (3.32 W/kg). And when he won the Tour of Flanders last month, Van der Poel’s weighted average power was a whopping 338 W (4.51 W/kg) … and that race was more than six and a half hours long – 90 minutes longer than Thursday’s super-slow Giro stage. Quite the difference.

In short, Thursday’s stage 6 of the Giro was almost trivially easy for those in the bunch. And yes, a good club rider probably could have kept up. At least until the pace (finally) started to increase in the closing kilometres, and when the jostling for position began …

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