Marcialonga Final Climb: What Average Power Does the Lead Pack Really Hold?

Segment: Marcialonga final climb

On Sunday it’s time for the 2020 edition of Marcialonga — a race very popular among Nordic skiers. One of the most fascinating features of Marcialonga is that the steepest and most decisive climb comes at the very end, unlike Vasaloppet where the major climb comes shortly after the start.

We’ve been curious: what average power is required to get up this final climb with the lead pack?
As a starting point, we use times from 2019 together with the distance and elevation profile of the climb. From the base of the hill to the finish in Cavalese, the climb is 2.25 km long with an average gradient of 7%.

Figure 1. Elevation profile of the final climb in Marcialonga.

In 2019, Petter Eliassen was the fastest man up the climb with a time of 8:27, corresponding to an average speed of 16.0 km/h. Among the women, Katerina Smutná was fastest with 11:43, an average speed of 11.5 km/h, closely followed by Britta Johansson Norgren, Lina Korsgren, and Astrid Øyre Slind.

What Average Power Do These Speeds Correspond To?

We can make a rough estimation using a simple mechanical force balance — something we described earlier in our analysis of the Vasaloppet start climb.
One uncertainty is glide friction, which we estimate at 0.025 (fairly fast conditions), based on the fact that the snow is mostly artificial and the TV footage showed mild, stable weather. Another uncertainty is Petter Eliassen’s weight. To avoid guessing too much, we focus on weight-normalized power (W/kg), which is what matters in steep climbs.

(1)  

However, we must consider that 16 km/h is fast enough that air resistance cannot be ignored. A rough estimate is that air drag adds another 6–7 N of resisting force — or roughly 30 watts. To convert this to W/kg we need an assumed body mass. With a height of 183 cm, we guess Eliassen weighs around 75–80 kg including equipment, which adds roughly 0.4 W/kg.

This puts Eliassen’s average climbing power at approximately 4.5 W/kg.
The greatest uncertainty in this calculation is the friction coefficient — but in a steep climb like this, friction contributes less to total variation. We can confidently estimate the true value lies between 4.3 and 4.7 W/kg, corresponding to ~325–375 W absolute power depending on weight.

What About the Women’s Lead Group?

What average power did Britta Johansson Norgren likely hold?
Ignoring air resistance initially, we land at around 3.0 W/kg. At the women’s lower speed, air drag plays a smaller role. Additionally, the women’s field climbed as a group, potentially reducing drag.

Assuming pack skiing offers only a small advantage, we can add ~0.2 W/kg. With uncertainties in conditions considered, the final estimate becomes:

Women’s lead pack power: 3.0–3.4 W/kg
In absolute terms: ~195–225 W.

/Dan