Feature articles

SpikeBoarding is Skiing: Mechanical Equivalence of Poling-Driven Propulsion on Roller Skis and Skateboards

February 20, 2026

Enrique G. Cubillo
SUSOIX LLC (enriquecubillo@gmail.com)

1. Introduction

Cross-country skiing biomechanics have been extensively studied, with particular attention to the relative contributions of pole and ski forces to forward propulsion. The development of roller skiing—skiing on wheeled platforms during non-snow seasons—has enabled year-round training and facilitated controlled laboratory research. Elite cross-country skiers routinely spend 70% or more of their training season on roller skis, and Olympic medalists cite roller skiing as integral to their preparation.

A fundamental question arises: what defines ‘skiing’ as a locomotor category? If skiing is defined by snow contact, then roller skiing is not skiing. If skiing is defined by the biomechanical pattern—coordinated pole and leg action generating propulsion—then the surface substrate becomes mechanically irrelevant. The existing literature implicitly adopts the latter definition by treating roller skiing as a valid expression of skiing biomechanics.

This paper extends that logic to its natural conclusion. If roller skiing is skiing because it expresses skiing biomechanics on a wheeled platform, then any technique expressing the same biomechanics on a mechanically equivalent wheeled platform is also skiing. SpikeBoarding’s two primary techniques—SUS and CXC—meet this criterion.

2. Background: The Zhao et al. (2023) Study

Zhao et al. (2023), published in Frontiers in Sports and Active Living (PMCID: PMC9992420), examined the contribution and effectiveness of ski and pole forces in double poling (DP) and Gear 3 (G3) techniques at moderate uphill inclines. Ten male cross-country skiers performed standardized techniques on a motorized treadmill using instrumented roller skis and pole force sensors.

Key findings relevant to the present argument:

- - In G3 technique, approximately 85% of total propulsive force was contributed by poles at each incline measured (3°, 4°, 5°).
  - Peak pole force increased by 32% from 3° to 5° incline in G3 technique.
  - In double poling, pole force effectiveness increased by 7% from 3° to 5° incline.
  - The role of legs was primarily supporting the body against gravity and repositioning body segments, not generating forward propulsion.

Critically, the force equations and kinematic measurements in the study contain no reference to ‘skiing’ as a categorical requirement. The study measures human whole-body locomotion on a wheeled platform using poles for propulsion. The physics would be identical if the platform were labeled differently.

3. Mechanical Equivalence of Platforms

A roller ski, stripped to its mechanical essentials, is a rigid platform with wheels at the front and rear, designed to support human locomotion. A skateboard is a rigid platform with wheels at the front and rear, designed to support human locomotion. Differences in wheelbase, wheel diameter, or steering articulation do not alter the fundamental propulsion mechanics under consideration, which arise from pole-ground interaction and whole-body coordination. There is no biomechanical principle that distinguishes these platforms as locomotor substrates with respect to poling-driven propulsion.

The differences between roller skis and skateboards are institutional and historical, not mechanical. Roller skis are classified as ‘skiing equipment’ because they were developed within the skiing community and named accordingly. Skateboards are classified as ‘skating equipment’ because they emerged from surf and skate culture. These classifications reflect social history, not physics.

The locomotor class of a human-platform system is determined by the propulsion method, not the platform name. A skateboard propelled by foot-pushing is skating. A skateboard propelled by poles engaging the same force patterns measured in skiing is skiing.

4. SUS and CXC Technique Analysis

SpikeBoarding comprises two primary techniques, both developed in 2010 and documented in continuous use for over fifteen years.

Stand Up Spike (SUS) is the foundation stroke of SpikeBoarding and corresponds biomechanically to double poling in cross-country skiing. Both arms act in unison, driving the skateboard spike into the pavement to generate forward propulsion. The legs remain fixed on the board, contributing to body support and power transmission but not to propulsive kicking. Video evidence of sustained SUS execution is available in the Mount Greylock summit video (https://www.youtube.com/watch?v=1Xx0AfjNbIE), documenting 75 minutes of continuous uphill propulsion using primarily SUS technique.

Cubi-X-Cross (CXC) corresponds biomechanically to diagonal stride in cross-country skiing. CXC combines diagonal upper-body arm action with contralateral switch-kicking on the skateboard platform. The arm action alternates sides, coordinated with opposite-side leg movement. Video evidence of CXC execution is available in the Griffith Park climb video (https://www.youtube.com/watch?v=5MOgq1gGXFI), documenting 20 minutes of continuous CXC climbing.

A third technique, Inside Cubi-X-Cross (ICXC), allows leg switching while one arm remains in constant action. ICXC is less commonly used than SUS and CXC but provides utility for carrying objects or recovering from arm fatigue.

Observable characteristics matching skiing biomechanics in both SUS and CXC:

- - 90-degree elbow angle maintained throughout the poling cycle, consistent with elite skiing technique.
  - Core-driven propulsion with lat and trunk engagement, not arm-driven movement.
  - Sustained uphill propulsion over extended durations (20-75+ minutes), demonstrating effectiveness for overcoming gravitational resistance.
  - In CXC, bilateral symmetry with switch-kicking across all four foot positions (left front, left rear, right front, right rear).

Full SpikeBoarding typically combines SUS and CXC according to terrain and athlete preference, as documented in the combined technique video (https://www.youtube.com/watch?v=LrW9Iu99xuM).

5. Epistemological Foundation: Observation as the First Act of Science

A potential objection to the foregoing argument is that SpikeBoarding has not been ‘quantified’ in the sense of instrumented laboratory measurement. This objection misunderstands the sequence of scientific inquiry in biomechanics.

In biomechanics, observation is the first act of science. A movement must first be seen, recognized, and described before it can be instrumented or quantified. Biomechanics did not begin with force plates; it began with Muybridge’s photographs, Marey’s chronophotography, and coaches watching bodies move. Running, walking, jumping, swimming strokes, and ski techniques all entered science because someone saw them and said: ‘That is a distinct pattern.’

Sight alone establishes: existence (the movement happens), stability (it persists over time), repeatability (it is not a fluke), coordination structure (phase relationships and sequencing), and functional success (it accomplishes a task). This is already biomechanics—descriptive biomechanics. Instrumentation does not create biomechanics; it refines it.

The historical precedent is instructive. There was no peer-reviewed biomechanics on the Fosbury Flop prior to Dick Fosbury winning Olympic gold in 1968. No force plates. No kinematic models. No instrumented validation. Fosbury did not validate the flop scientifically; he forced science to catch up. The flop entered high jump technique not because journals authorized it, but because performance reality was undeniable. Science followed because it had no choice.

The same logic applies here. SpikeBoarding has been seen, is coherent, is repeatable, is task-complete, and visibly instantiates known skiing coordination patterns. It has therefore already crossed the first and most fundamental scientific threshold. The absence of published measurements reflects a lack of instrumentation, not a lack of underlying forces or coordination patterns.

6. Discussion

The argument presented here does not require SpikeBoarding to be instrumentally measured to establish its validity. Existence precedes measurement. The forces, kinematics, and motor-control patterns exist in SUS and CXC whether or not sensors have been applied. Video evidence demonstrates stable, repeatable, effective propulsion—sufficient to establish that the techniques work.

What the Zhao et al. paper provides is not proof that SpikeBoarding works—that is already evident—but proof that the biomechanical class to which SpikeBoarding belongs has already been validated. The paper measured the engine (poling-driven propulsion). The videos demonstrate that the same engine operates on a different chassis (skateboard instead of roller ski). The physics does not distinguish between chassis types.

Any claim that SUS or CXC is ‘not skiing’ must therefore identify a biomechanical principle that excludes them from the category. No such principle exists. The only basis for exclusion is categorical: the platform is called a ‘skateboard’ rather than a ‘ski.’ This is a naming convention, not a scientific distinction.

7. Conclusion

SpikeBoarding is skiing. The peer-reviewed literature has already validated poling-driven propulsion on wheeled platforms. The platform used in that validation (roller ski) is mechanically equivalent to the platform used in SpikeBoarding (skateboard) with respect to the propulsion mechanics under consideration. SUS corresponds to double poling; CXC corresponds to diagonal stride. The propulsion methods are the same. The force patterns are the same. The locomotor class is the same.

The barrier to recognition is not scientific—it is categorical. Institutions have pre-classified ‘roller skiing’ as skiing and ‘skateboarding’ as skating based on historical naming, not mechanical analysis. SpikeBoarding demonstrates skiing biomechanics on a platform that was never labeled as skiing equipment.

Future instrumented studies could further characterize the mechanics described here, providing a direct empirical bridge between observed equivalence and measured mechanics. Such studies would quantify what is already functionally demonstrated. SpikeBoarding is skiing, and the existing literature already establishes the biomechanical class to which it belongs.