Korfball Fitness

 

Introduction Korfball is not a Running Game

In June 2026, the Dutch national korfball team gathered in Portugal for a training camp. During the camp, the technical staff administered the 20-metre shuttle run test (the beep test).

Why does the technical staff of the Dutch national team use this non-specific running test after a demanding season? What information are they seeking, and what is the intended purpose? Given the expertise of the KNKV staff, we may expect that there is a deliberate rationale behind this choice.

In the shuttle run test, performance is determined by the highest level completed and the number of 20-metre shuttles successfully run. Participants run continuously between two lines, synchronising their pace with audio signals. Every minute, the interval between the beeps decreases, requiring progressively higher running speeds. For adult men, reaching levels 7–10 is considered satisfactory, while levels 6–8 are considered satisfactory for women. Scores above level 13 are regarded as excellent, although interpretation depends on age and gender.

Is the Shuttle Run Test a Measure of Korfball Fitness?                                                                                               Coaches who adopt the Action Theory perspective argue that this test is unsuitable for measuring korfball fitness because it lacks specificity. From an Action Theory perspective, this criticism is justified. The shuttle run test measures physiological running capacity rather than the fitness required to perform successfully in korfball. It therefore measures a physical prerequisite rather than korfball fitness itself.

In korfball, communication and decision-making constitute the action itself. Running, accelerating, decelerating, and changing direction are not driving forces of the game; they emerge as consequences of the tactical situation, interactions with teammates and opponents, and the rules of the game. Fitness is therefore not the game itself but a supporting capacity that enables players to meet the demands created by the game.

This criticism is increasingly supported by modern sports science and by coaches working in elite team sports. The central weakness of the beep test is its lack of ecological validity: it bears little resemblance to the actual performance environment of a korfball match.

The shuttle run test provides a useful indication of physiological capacity, but it fails to capture several essential components of korfball performance.

Absence of Cognitive Stimuli                                                                 During the beep test, the player responds only to a predictable external signal: the beep.

During a match, however, players constantly respond to unpredictable stimuli such as teammates, opponents, the ball, available space, and rapidly changing tactical situations.

Consequently, korfball fitness is inseparable from game intelligence. A player who reads the game effectively runs fewer unnecessary metres and conserves energy, regardless of their beep test score.

Linear Versus Multidirectional Movement                                                                                                                             The beep test consists of repeated straight-line runs over 20 metres with a 180-degree turn.

Korfball movements are more complex. Players accelerate, decelerate, curve, sidestep, backpedal, jump, rotate, and engage in physical contests. These multidirectional actions impose mechanical demands that the shuttle run test cannot reproduce.

Absence of Technical Actions                                                                                                                                                     The beep test involves running without a ball or technical tasks.

In contrast, korfball requires players to accelerate, decelerate, create separation from defenders, communicate through movement, receive the ball, and execute technically demanding skills while fatigued.

Technical execution increases physiological load. A technically proficient player often performs more efficiently than a player with excellent running capacity but inferior technical skills.

Why Is the Test Still Used?                                                                       Despite these limitations, the shuttle run test remains valuable as a simple, inexpensive, standardised, and reliable measure of aerobic and anaerobic fitness.

It should therefore be viewed as a general physiological screening tool rather than a measure of korfball performance.

Many elite clubs increasingly complement or replace such laboratory tests with GPS data collected during training sessions and matches. These data provide contextual information about the physical demands experienced by individual players during real game situations. However, GPS data are meaningful primarily at the individual level and only when analysed across multiple matches and training sessions. Comparing GPS data between players is of limited value because each player fulfils a unique tactical role within the team.

Is Korfball Fitness More Than Physiological Capacity?                                                                                       Absolutely. This question lies at the heart of modern sports physiology. Fitness in complex team sports extends far beyond cardiovascular endurance.

If korfball fitness is defined as the ability to maintain high-quality performance throughout an entire match, then the true measure of fitness is not maximal oxygen uptake but the extent to which performance declines between the opening whistle and the final seconds of the game.

This decline results from the interaction of four interconnected systems.

1. Neuromuscular Fitness                                                                                                                                                       Late in the match, limitations often arise not from the lungs but from the nervous system and the muscles themselves.

Repeated explosive movements—including sprinting, braking, jumping, and changing direction—produce temporary muscle damage and disturbances in calcium and potassium regulation. At the same time, the central nervous system becomes less effective at activating the muscles, a phenomenon known as central fatigue.

2. Metabolic Fitness                                                                                                                                                                  Even players with exceptional aerobic capacity eventually experience local muscular fatigue.

Korfball relies heavily on glycogen stored within specific muscle fibres. As these local energy reserves become depleted, explosive actions become increasingly difficult, even though the cardiovascular system continues to function normally.

The limiting factor is therefore not oxygen delivery but the availability of energy within the working muscles.

3. Cognitive and Mental Fitness                                                                                                                                            Elite korfball requires continuous perception, anticipation, communication, and decision-making under severe time pressure.

Mental fatigue is therefore an essential component of korfball fitness.

After prolonged periods of scanning, positioning, and tactical decision-making, players begin to react more slowly, make poorer positional choices, and execute passes less accurately. These cognitive errors increase physical workload because players are forced to make additional corrective movements.

Physical fatigue and cognitive fatigue continuously reinforce one another.

4. Mechanical Resilience                                                                                                                                                Korfball also requires muscles, tendons, and connective tissues that can tolerate repeated eccentric braking, jumping, landing, and physical contact.

An athlete with excellent cardiovascular fitness, such as a cyclist or swimmer, may nevertheless experience severe muscular fatigue after only a short period of playing korfball because their tissues are not adapted to these mechanical demands.

Mechanical resilience therefore determines how efficiently players can continue performing throughout the match.

Developing Competition Fitness                                                                                                                               Competition fitness is the ability to prevent a substantial decline in performance under the unique physical, tactical, and psychological demands of competition.

From the perspective of performance psychology, as described by Professor Nico van Peren and others, optimal performance does not require eliminating pressure. Rather, athletes must learn to accept pressure while maintaining attention on task execution.

The Relational View and Action Theory [1]                                                            Within Action Theory, the player is understood as part of a continuously changing relationship involving teammates, opponents, tactical situations, and the objectives of the game.

Training should therefore develop not only physical capacity but also the player's ability to function effectively within these relationships.                                    

1. Training the Psychological Foundations                                                                                                            Performance psychology identifies three fundamental psychological needs:

• Autonomy
• Competence
• Connection

Under extreme competitive pressure, players may unconsciously shift into a survival mode characterised by fear of failure and avoidance behaviour. Training should help players recognise these mental states and deliberately return their attention to their task.[2] Coaches and teammates support this process by strengthening the player's sense of competence, autonomy, and connection, thereby restoring confidence and effective performance.

2. Applying Psychological Knowledge [3]                                                                                                                                      To minimise the gap between training and competition, several evidence-based psychological interventions can be incorporated into daily practice.

Focus on the process rather than the outcome. Anxiety often arises when attention shifts towards winning or avoiding failure. Players should instead concentrate on immediate task execution and the aspects of performance within their control.

Psychological Skills Training (PST). Mental skills should be trained systematically alongside technical and tactical skills.                                                                               These include:

• Developing pre-performance routines that provide stability under pressure.
• Using visualisation to rehearse successful performance under both normal and stressful conditions.
• Applying breathing techniques to regulate physiological arousal and maintain concentration.

Self-compassion. Within the relational view of human nature, maintaining a healthy relationship with oneself is essential. Athletes who respond to mistakes with excessive self-criticism are more likely to experience performance breakdowns under pressure. Instead, errors should be interpreted as information about task execution rather than as judgments of personal worth.

Competition fitness therefore emerges from the integration of physiological capacity, neuromuscular resilience, cognitive performance, psychological skills, technical competence, and tactical intelligence. From an Action Theory perspective, fitness cannot be separated from the game itself; it is the capacity to continue acting effectively within the continuously changing relationships that constitute korfball.

 

 

[1] Read: The Art of Korfball Coaching 2021 Chapter 5. Physical Aspects

[2] It concerns ownership with which the player commits and for which he is competent.

[3] Read: The Art of Korfball Coaching 2021 Chapter 4. Performance behaviour

Ben Crum