Compound score, developed by WorldTour sports scientists, offers insights that suggest it may outperform power-to-weight in predicting race performance.
Cor Vos
Watts of power produced per kilogram of body weight has long been cycling’s default metric for standardised power comparison. The elegant metric evens out differences in rider size and reduces physical ability to a single, clean number. All you have to do is divide watts by kilos, and in theory, you’ve levelled the playing field.
It wasn’t just the ease of the metric that propelled it into every cyclist’s vocabulary, either. It was also because of its validity in what is often seen as cycling’s testing ground – climbs, where races are often seen to be won and lost.
But according to research led by Peter Leo, a research fellow in the Department of Sport Science at the University of Innsbruck and coach with Jayco-AlUla, it doesn’t explain who wins races. “The predictive ability of relative power (W/kg) is not great,” Leo told Escape Collective. When comparing riders in the same races, the mismatch was clear. “Despite very good relative power numbers, we couldn’t explain why some riders with better power-to-mass ratios were finishing behind others.”
That’s the gap that compound score, which Leo and his fellow researchers came up with in 2022 and published in 2023 in the Journal of Science and Medicine in Sport, is trying to fill. Combining absolute power with relative power, it captures whether athletes have the raw engine to survive in a chassis to make a difference when it counts.
Although the concept is just four years old, it’s already making inroads in pro cycling. Leo’s research collaborator, John Wakefield, director of coaching, sports science and technology at Red Bull-Bora-Hansgrohe, said it’s become a key part of his talent evaluation. “When I analyse riders, it’s the first metric I look at,” he told Escape. “I use it very much within our recruiting and scouting protocols.”
While not perfect, the compound score also has a more accurate performance than relative power alone in predicting likely podium contenders for major one-day races in particular. The insights it offers could help coaches like Leo and Wakefield more effectively identify and develop talents by better understanding the foundations of elite physiology.
Why does W/kg struggle?
On flat and rolling terrain, power-to-weight ratio matters far less than absolute power and aerodynamics. At 390 watts, a 65 kg rider produces 6 W/kg. For an 80 kg rider, that same power is achieved at 4.88 W/kg. But the key forces working against the rider on that terrain are primarily aerodynamic drag, which doesn’t scale with rider size the way absolute power output tends to. On the flat, where gravity isn’t a limiter, there is a clear advantage to the heavier rider. There are exceptions; drag is highly individual, which is why a relatively lightweight rider like 63 kg Remco Evenepoel can beat much larger riders like Filippo Ganna, who is 20 kg heavier, even in flat time trials.
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