Yo Score of 20: Understanding the Yo-Yo Intermittent Recovery Test, Performance, and Improvement

What is a Yo Score of 20?

A "Yo score of 20" most commonly refers to the completion of Level 20 in the Yo-Yo Intermittent Recovery Test Level 1 (YYIRT1), signifying a high level of intermittent aerobic fitness and recovery capacity, particularly relevant for athletes in sports demanding repeated high-intensity efforts.

Introduction to the Yo-Yo Intermittent Recovery Test (YYIRT)

The Yo-Yo Intermittent Recovery Test (YYIRT), developed by Professor Jens Bangsbo, is a widely recognized and scientifically validated field test used to assess an individual's ability to perform repeated high-intensity efforts interspersed with short recovery periods. Unlike continuous aerobic tests, the YYIRT specifically targets the physiological demands of many team and combat sports, which involve bursts of intense activity followed by brief rest or low-intensity movements.

There are primarily two versions:

• Yo-Yo Intermittent Recovery Test Level 1 (YYIRT1): Designed for a broader range of athletes, assessing the capacity to recover from repeated high-intensity efforts.
• Yo-Yo Intermittent Recovery Test Level 2 (YYIRT2): A more demanding version for elite athletes with higher fitness levels.

When discussing a "Yo score" without further qualification, it typically refers to the YYIRT1 due to its more widespread application across various athletic populations.

Understanding the Yo-Yo Test Scoring System

The YYIRT involves participants running back and forth between two lines (20 meters apart) at progressively increasing speeds, dictated by audio signals from a pre-recorded CD or software. After each shuttle (a 40-meter round trip), there's a 10-second active recovery period where the participant walks or jogs around a cone placed 2.5 meters behind the starting line. The test continues until the participant fails to reach the designated line twice in succession, or voluntarily withdraws.

The score is recorded as the total distance covered, often expressed as the "level" completed or the total meters. Each level corresponds to a specific speed and accumulated distance.

Deconstructing a "Yo Score of 20"

A "Yo score of 20" refers to the successful completion of Level 20 in the Yo-Yo Intermittent Recovery Test Level 1 (YYIRT1).

To understand what this entails:

• Test Progression: The YYIRT1 starts at a relatively low speed (8 km/h) and progressively increases. Each "level" consists of a set number of 20-meter shuttles at a specific speed, followed by the 10-second recovery.
• Level 20 Specifics:
  • Speed: To complete Level 20, the athlete must successfully run the shuttles at a speed of 17.5 km/h.
  • Shuttles: Level 20 itself consists of two 20-meter shuttles (one 40-meter round trip) at this speed.
  • Total Distance: Successfully completing Level 20 means the athlete has run a cumulative total distance of 1200 meters (including all previous levels and shuttles).
  • Recovery: This performance includes managing the 10-second active recovery periods between each 40-meter shuttle throughout the entire test.

This score indicates not just the ability to run at a certain speed, but critically, the capacity to repeat these high-intensity efforts with limited recovery.

What a Yo Score of 20 Indicates for Performance

Achieving a Yo score of 20 (1200 meters) in the YYIRT1 is generally considered a very good to excellent score, particularly for team sport athletes.

• High Aerobic Capacity (VO2max): While not a direct measure, the YYIRT1 score correlates strongly with maximal oxygen uptake (VO2max). A score of 1200m often corresponds to an estimated VO2max in the range of 55-60+ ml/kg/min for adult males, and slightly lower but still excellent for females. This signifies a well-developed cardiovascular system capable of delivering oxygen efficiently to working muscles.
• Superior Intermittent Recovery Ability: The essence of the YYIRT is recovery. A score of 20 demonstrates robust physiological mechanisms for clearing metabolic byproducts (like lactate) and replenishing phosphocreatine stores during the short recovery intervals. This is crucial for maintaining high-intensity performance throughout a game or match.
• Athletic Profile: Athletes in sports like soccer, basketball, field hockey, rugby, and even some combat sports, who achieve a Yo score of 20 or higher, typically possess the physical endurance and resilience required to perform at high levels, sustain repeated sprints, and maintain work rate throughout prolonged periods. It suggests they can cope with the fluctuating demands of their sport effectively.
• Fatigue Resistance: This score indicates a high level of fatigue resistance, meaning the athlete can delay the onset of fatigue and maintain performance quality even as the test becomes more demanding.

Factors Influencing Yo-Yo Test Performance

Several physiological and training factors contribute to an individual's Yo-Yo test score:

• Aerobic Fitness: A strong aerobic base is fundamental, as it underpins recovery and sustained effort.
• Anaerobic Capacity: The ability to produce energy without oxygen is critical for the high-intensity shuttles.
• Speed and Agility: While not a pure speed test, the ability to accelerate and decelerate efficiently contributes.
• Running Economy: How efficiently oxygen is used during running.
• Muscle Power and Strength: Essential for acceleration and maintaining running form under fatigue.
• Recovery Efficiency: The physiological mechanisms for lactate clearance and phosphocreatine resynthesis during the 10-second breaks.
• Motivation and Mental Toughness: The test is highly demanding and requires significant mental fortitude to push through discomfort.
• Environmental Factors: Temperature, humidity, and altitude can affect performance.

Improving Your Yo-Yo Test Score

Improving your Yo-Yo score requires a multifaceted training approach:

• High-Intensity Interval Training (HIIT): Incorporate drills that mimic the work-to-rest ratios of the Yo-Yo test, such as repeated sprint ability (RSA) training, short sprints with active recovery, and specific shuttle runs.
• Aerobic Base Training: Develop a strong aerobic foundation through longer, steady-state runs or tempo runs to enhance cardiovascular efficiency and recovery.
• Speed Endurance: Train at or above your target Yo-Yo test speeds for short durations to improve tolerance to high-speed efforts.
• Strength and Power Training: Focus on compound movements (squats, deadlifts, lunges) and plyometrics to improve lower body power, which aids in acceleration and deceleration.
• Sport-Specific Drills: Integrate drills from your sport that involve intermittent high-intensity efforts to make training more relevant and engaging.
• Nutrition and Hydration: Optimize fuel intake and maintain proper hydration to support intense training and recovery.
• Recovery Strategies: Prioritize sleep, active recovery, and other recovery modalities to ensure your body can adapt to training loads.

Limitations and Considerations

While the Yo-Yo Intermittent Recovery Test is an excellent tool, it's important to consider its limitations:

• Test Specificity: It is a running-based test. While relevant for many sports, it may not perfectly reflect the metabolic demands or movement patterns of all activities (e.g., swimming, cycling, or sports with significant directional changes beyond linear shuttles).
• Motivation Dependent: As with many maximal effort tests, an individual's motivation can significantly impact their score.
• Not a Diagnostic Tool: It provides a performance score but doesn't diagnose underlying physiological issues.
• Population Norms: Scores should be interpreted in context, considering age, gender, training history, and sport-specific demands. What is "excellent" for a recreational athlete might be "average" for an elite professional.

Conclusion

A "Yo score of 20" in the Yo-Yo Intermittent Recovery Test Level 1 represents a robust level of intermittent aerobic fitness, characterized by a strong ability to perform repeated high-intensity efforts and recover efficiently between them. This score is a valuable indicator for athletes and coaches, providing insight into an individual's capacity to meet the demanding physiological requirements of intermittent sports. Understanding what this score means, how it's achieved, and how to improve it empowers athletes and trainers to optimize performance and training strategies.