He’s the Fastest Man Alive—and He’s Running Uphill on Skis

Key Concepts

• Moment of Inertia: A measure of an object's resistance to changes in its rotation. Lower moment of inertia allows for faster rotation/leg swing.
• Glide Phase: The portion of a cross-country ski stride where the ski is rolling forward to conserve energy, typically used on uphill sections.
• Swing Phase: The portion of a cross-country ski stride where the leg is lifted and moved forward.
• Metabolic Cost: The amount of energy expended by the body during an activity.
• Kickback (Kick Wax): The grip provided by wax on the ski to propel the skier forward, particularly uphill.

The Revolutionary Skiing Technique of Johannes Høsflot Klæbo

Johannes Høsflot Klæbo’s cross-country skiing technique represents a significant departure from traditional methods, contributing to his record-breaking four Olympic gold medals and status as the most decorated winter Olympian. This technique, largely developed with the guidance of his grandfather and coach, fundamentally alters the energy expenditure paradigm in cross-country skiing. Traditionally, skiers conceptualize energy management as “burning matches,” conserving effort for optimal performance. Klæbo’s approach, however, is described as “lighting the whole box at once” – a high-intensity, metabolically demanding style.

Eliminating the Glide Phase & Reducing Moment of Inertia

The core innovation lies in Klæbo’s approach to uphill skiing. While conventional technique emphasizes the glide phase – rolling the ski forward to conserve energy during ascents – Klæbo actively eliminates this phase. Instead of gliding, he immediately initiates the next stride, maintaining constant propulsion. This is achieved through a unique modification during the swing phase.

He dramatically increases knee bend during the swing phase, effectively reducing his moment of inertia. This principle, analogous to a sprinter snapping their leg forward with greater speed, allows for a faster leg cycle. Specifically, Klæbo keeps each leg in the air for 61% of his stride, a substantial increase compared to the traditional 41%. This increased air time, coupled with the reduced moment of inertia, translates to a significantly faster and more powerful stride.

Origins and Development of the Technique

The technique wasn’t a product of deliberate scientific design, but rather an accidental discovery approximately a decade ago. During a training session, Klæbo became frustrated with slipping uphill due to inadequate kickback (grip from the ski wax). His grandfather, acting as coach, timed him with a stopwatch and observed Klæbo’s unexpectedly faster speed despite the unconventional form. This observation formed the basis for refining and implementing the technique.

Physiological Demands and Training Regimen

The Klæbo stride is exceptionally demanding, requiring an extraordinary level of physical fitness to execute without losing balance. It’s a metabolically costly strategy, meaning it requires a huge amount of energy. Consequently, Klæbo rarely practices the technique directly during training. Instead, his training focuses on building an immense aerobic base through over 1,000 hours of grueling cardiovascular workouts annually. This extreme fitness level is crucial to sustaining the high energy output required by the technique.

Adoption and Replication Challenges

Despite its proven success, the Klæbo stride is notoriously difficult to replicate. It is now being taught in ski schools across Scandinavia, but instructors acknowledge that few skiers can successfully implement it without risking injury. The technique’s complexity and physiological demands mean that it’s not universally applicable, and attempting it without sufficient conditioning can lead to physical strain.

Conclusion

Johannes Høsflot Klæbo’s skiing technique represents a paradigm shift in cross-country skiing, prioritizing explosive power and continuous propulsion over traditional energy conservation methods. Rooted in an accidental discovery and refined through dedicated training, the technique’s success underscores the importance of both biomechanical innovation and exceptional physical conditioning. While challenging to replicate, the Klæbo stride has undeniably redefined the boundaries of performance in the sport.