Theory and Models Sports Science PDF

Theory and Models 1 1. Overview Focuses on interdisciplinary theories and models in sports science. Applications span health sports, recreational sports, fitness, and competitive sports. 2. Evidence-Based Models Origin of Evidence Pyramids: o Rooted in the me...

Theory and Models 1 1. Overview Focuses on interdisciplinary theories and models in sports science. Applications span health sports, recreational sports, fitness, and competitive sports. 2. Evidence-Based Models Origin of Evidence Pyramids: o Rooted in the medical field, ranks evidence quality from lowest to highest. Example: Randomized Controlled Trials (RCTs) with female athletes and menstrual cycles. Highest level of evidence: Meta-Analysis 3. Coaching vs. Science Science Perspective: o Interested in generalizable, group-level data. o Focuses on eliminating confounding variables. o Standardization with large populations. Coaching Perspective: o Addresses individual athlete needs. o Integrates confounding variables (e.g., personal history, emotions). o Relies on blending science and practical experience. 6. Linear vs. Non-Linear Systems Linear: o Stable, predictable, repeatable. o Often oversimplifies complex biological processes. Non-Linear: o Dynamic, sensitive, unpredictable. o More representative of human physiological systems. 7. Theories vs. Models Aspect Theory Model Purpose Explains broad phenomena. Represents specific processes. Scope Broad and abstract. Narrow and concrete. Predicts outcomes or applies Function Generates hypotheses. theories. Application Conceptual framework. Practical tool for decision-making. Overload Principle, Central Example FITT Model, Hill Muscle Model. Governor. 8. Why Use Models? Simplify complex systems for better understanding. Aid in decision-making for coaches. Provide a standardized framework for research and application. 9. Inductive vs. Deductive Reasoning Inductive: Specific observations → General theories. Deductive: General theories → Specific predictions. 10. Coaching Framework Factors influencing coaching decisions: o Athlete's biology (fatigue, thermoregulation, menstrual cycle). o Psychological models (stress-response, motivation). o External factors (environment, financial resources). o Technology: Tools for monitoring training and performance. 11. Personalized Training Tailoring based on: o Athlete's performance outcome. o Day-to-day adjustments. o Long-term cost/benefit assessment. o Psychological and physiological readiness. Challenges and Issues with Periodization 2 1. Key Concepts Periodization: Strategic division of training into phases (macrocycle, mesocycle, microcycle) to optimize performance. o Macrocycle: Long-term plan (>10 weeks). o Mesocycle: Medium-term focus (2–10 weeks). o Microcycle: Short-term cycle (typically a week). Based on the General Adaptation Syndrome (GAS): o Alarm reaction, resistance, exhaustion stages. o Training stress → Adaptation. 2. Biological and Genetic Factors Phenotype Variations: Each individual adapts di]erently to training due to genetic di]erences. Genetic markers can predict up to 49% of VO2max trainability. 3. Training Models Polarized Training: o High percentage in low-intensity (Zone 1) and a smaller focus on high- intensity (Zone 3). Pyramidal Training: o High emphasis on Zone 1, moderate use of Zone 2, limited Zone 3. Threshold Training: o Balanced focus on moderate to high intensity. 4. Intensity Zones Zone 1: Low intensity (heart rate/Borg 15). 5. Timing and Recovery mRNA adaptation levels return to baseline within 24 hours after training. Timing sessions is critical. Reproducibility Issues: Responses to identical training plans can vary, highlighting the need for flexibility. Injury prevention (e.g., British athletes lose ~49 training days annually due to injury). 6. Mixed vs. Block Periodization Mixed Periodization: Targets multiple areas simultaneously. Block Periodization: Focuses on specific areas (e.g., strength or endurance) for better adaptation. 7. Monitoring and Adaptation Use of tools like heart rate monitors for 24-hour tracking of training load and intensity. Establishing early warning systems to avoid overtraining or injury (e.g., "tra]ic light" systems). 8. Considerations for Coaches Individualize training based on: o Athlete's history (stress, injury, training availability). o Resources and limitations (nutrition, finances, time). o Feedback loops with athletes. Periodization templates are guidelines, not fixed rules. Adapt based on evidence and situational needs. Endurance Training Models 3 1. Endurance Performance and VO2max VO2max: Maximum oxygen uptake is the highest rate the body can use oxygen during exercise. It is a primary determinant of endurance performance. o Typical VO2max values: § Healthy, sedentary adults: ~30-40 mL/min/kg. § Elite athletes: 70-90 mL/min/kg (e.g., Paula Radcli]e 75 mL/min/kg). § Children (9–11 years): 32-55 mL/min/kg. § Cross-country skiers (highest values): 85–90 mL/min/kg (male), 75–84 mL/min/kg (female). o Improvement Example: A sedentary middle-aged person showed an 18% VO2max increase over 2 years (from 29.0 to 34.4 mL/min/kg). 2. Fick Equation and Oxygen Transport Fick Equation: Describes oxygen transport: o VO2 = HR × SV × (a-vO2 diYerence) § HR: Heart rate. § SV: Stroke volume. § (a-vO2): Arteriovenous oxygen di]erence.  Maximal Lactate Steady State (MLSS): o The exercise intensity where lactate production = lactate clearance. o Exercise above MLSS leads to lactate accumulation and acidosis, limiting performance. o For intensities below MLSS, duration depends on glycogen stores. 3. Running Economy (RE) Definition: Energy expenditure at a specific submaximal running speed (lower oxygen consumption = better economy). Typical VO2 values at 16 km/h: o East African runners: ~39–40 mL/min/kg. o Paula Radcli]e: 44 mL/min/kg. o Average sports students: ~48–65 mL/min/kg (lower e]iciency compared to elites). RE Improvement Strategies: o Endurance training: Long-term adaptations improve e]iciency. o Strength training: § Improves leg sti]ness (e.g., Achilles tendon sti]ness ↑ 16% → Better energy storage). § Movement-specific training like uphill running is especially e]ective. o Altitude training: Boosts oxygen transport (↑ Hemoglobin mass). o Technology: Advanced footwear reduces energy cost by ~4%. 4. Key Training Models 1. High-Intensity Interval Training (HIIT): o Benefits: Running economy improvement (1–7%). o Works on VO2max and lactate thresholds. 2. Basic Training: o Focus: Long-term endurance improvement by increasing weekly mileage. o Example: After 12 days of basic training, performance improved by 21%. 3. Threshold Training: o Target: Training at or near lactate thresholds (MLSS) to enhance lactate clearance. 4. Strength Training: o Specific strategies (e.g., 90% MVC for calf muscles) improve running economy by ~4%. 5. Altitude Training Improves endurance performance via: o ↑ Hemoglobin mass → Better oxygen delivery. o Typical RE improvements: +2–7% after altitude exposure. Challenges: Variability in e]ects due to di]erences in: o Altitude exposure duration. o Environmental conditions (cold, sleep, diet). 6. Challenges in Endurance Training Research Small sample sizes. Variability in individual responses to training programs. Environmental factors (e.g., lab vs. real-world conditions). Strength Training Adaptions Models 4 1. Muscle Plasticity and Adaptation Muscle Plasticity: The ability of muscle fibers to adapt to di]erent types of stress (e.g., hypertrophy, atrophy, fatigue). o Types of Adaptations: § Hypertrophy: Increase in muscle size, typically from strength training. § Atrophy: Decrease in muscle size due to lack of use or disease. § Sarcopenia: Age-related muscle loss. § Dystrophy: Progressive degeneration of muscle fibers. Neuronal Adaptations: o Improved coordination of motor units and muscle fibers. o Activation of more motor units, leading to better strength and endurance. 2. Excitation-Contraction Coupling Definition: The process by which an electrical signal (excitation) leads to muscle contraction. 1. Excitation: A nerve impulse releases acetylcholine, triggering an action potential in the muscle. 2. Coupling: Calcium ions are released inside the muscle cells and bind to specific proteins. 3. Contraction: Myosin heads interact with actin filaments, pulling them to shorten the muscle and produce force. 3. Muscle Fiber Types Type I (Slow-Twitch): o Characteristics: High endurance, low power, and fatigue-resistant. o Function: Primarily involved in prolonged activities such as distance running. Type II (Fast-Twitch): o Type IIa: Fast and moderately fatigue-resistant (used in activities like middle-distance running). o Type IIx: High power, fatigues quickly (used for sprints or high-intensity strength activities). Recruitment Order: Slow-twitch fibers are recruited first, followed by fast-twitch fibers as the intensity increases. 4. Hypertrophy Mechanisms Neuronal Adaptations: Early in strength training, the body becomes more e]icient at activating motor units, improving strength without changes in muscle size. Morphological Adaptations: Muscle fibers increase in thickness as a result of strength training, leading to hypertrophy. o Protein Synthesis: Increased synthesis of muscle proteins contributes to muscle growth. o Microtrauma: Small muscle tears that repair with increased protein synthesis and fiber thickness. 5. Strength Training Models Mechanical Stress: Strength training (e.g., lifting weights) causes microtraumas in muscle fibers, which leads to muscle growth during recovery. Metabolic Stress: Accumulation of metabolites (e.g., lactate) during strength training stimulates hypertrophy. Neuronal Stress: Increased neural activation through electrical stimulation or voluntary contraction (EMS). 6. Hormonal and Metabolic Influence on Adaptation Hormonal Factors: o Testosterone: Promotes muscle growth and strength gains. o Growth Hormone (hGH): Stimulates muscle regeneration. o Cortisol: A catabolic hormone that can hinder muscle recovery if elevated too long. o Insulin-Like Growth Factor (IGF): Contributes to muscle repair and growth. Metabolic Stress: o Metabolic byproducts (e.g., lactate, ROS) stimulate protein synthesis and muscle growth during recovery. Hypoxia and Hyperoxia 5 1. Oxygen Transport and Diausion (HKS System) Oxygen Entry: Oxygen enters the body through convection (airflow) into the respiratory system and then di]uses across the alveolar membrane into the bloodstream. o DiYusion: Oxygen moves from areas of high concentration (lungs) to low concentration (blood). o Hemoglobin Binding: Oxygen binds to hemoglobin (Hb) for transport to tissues. 2. Dalton's Law of Partial Pressures Dalton’s Law: The total atmospheric pressure is the sum of the partial pressures of the individual gases (oxygen, nitrogen, and carbon dioxide). o Example: At sea level (760 mmHg): § Oxygen (PO2): 160 mmHg (21% of 760 mmHg). § Nitrogen (PN2): 593 mmHg (78% of 760 mmHg). 3. Hypoxia and Hyperoxia Hypoxia: Oxygen deficiency in tissues due to reduced environmental oxygen (altitude) or restricted blood flow (ischemia). o Acute EYects: Immediate body responses to lower oxygen, including increased heart rate (HR) and respiration. o Chronic Adaptation: Over time, the body adapts by producing more red blood cells via erythropoiesis, improving oxygen transport. Hyperoxia: Increased oxygen levels, either by using supplemental oxygen (hyperbaric) or at sea level. o EYects: Provides enhanced oxygen delivery, improving aerobic capacity and recovery.  o Hyperoxic Recovery: Breathing pure oxygen during recovery speeds up the elimination of metabolic by-products (e.g., lactic acid) and improves recovery time. 4. Hypoxic Training Methods Live High, Train Low (LHTL): o Athletes live at high altitudes to increase red blood cell production but train at lower altitudes to maintain training intensity. o Improves oxygen-carrying capacity, which enhances endurance performance at sea level. Artificial Hypoxia: o Normobaric Hypoxia: Reduced oxygen levels at normal atmospheric pressure (e.g., hypoxic tents, masks). o Hyperbaric Hypoxia: Lower oxygen levels at increased pressure (less common for training). Acute Hypoxic Exposure: Short bursts of exercise or training in hypoxic conditions to stimulate the body’s adaptation to lower oxygen availability. Training Duration: For optimal results, athletes should be exposed to hypoxic conditions for 12 hours a day over several weeks to maximize erythropoiesis. 5. Hyperoxic Training Mechanism: Breathing high concentrations of oxygen before or during training allows athletes to exercise at higher intensities with reduced fatigue, as oxygen delivery to muscles is enhanced. Acute Hyperoxia EYects: Increased PO2 (oxygen partial pressure) allows for better tissue oxygenation and improved endurance performance. Chronic Hyperoxia EYects: Can improve VO2max and aerobic capacity over time, leading to better performance during endurance events. Hyperoxic Recovery: Breathing pure oxygen during recovery can reduce muscle soreness and speed up recovery, particularly in high-intensity training. 6. Training in Hyperoxia vs. Normoxia Meta-analysis: Studies show that hyperoxic training leads to: o Enhanced exercise performance, including increased VO2max and running economy. o The improvements are more pronounced in subelite athletes. o Elite athletes might experience smaller gains compared to those training at normal oxygen levels (normoxia). 7. Side Eaects of Hyperoxic Training Oxygen Toxicity: Prolonged exposure to high oxygen levels (>1.5 ATA) can lead to damage to lung tissue and other negative health e]ects. o Free Radical Formation: High oxygen levels can lead to oxidative damage, particularly to lipids and proteins.  o Vasoconstriction: Hyperoxia can impair blood flow, reducing the e]iciency of oxygen transport to muscles during intense exercise. 8. Carbon Monoxide (CO) and Hypoxia CO Toxicity: CO binds with hemoglobin 240 times more readily than oxygen, reducing the blood’s ability to carry oxygen. This can lead to poisoning at high concentrations. o Chronic Low-Dose CO Exposure: Some studies suggest that repeated exposure to low levels of CO may enhance VO2max and hemoglobin mass by increasing red blood cell production. o Regulatory Concerns: Carbon monoxide rebreathing is banned for performance enhancement but is used for testing hemoglobin mass. Health models 6 1. What is Health? WHO Definition: "Health is a state of complete physical, mental, and social well- being, and not merely the absence of disease or infirmity." o Key Point: This definition emphasizes that health is not only the absence of disease, but the presence of well-being in various aspects of life (physical, mental, and social). 2. Biopsychosocial Model of Health Perspective: Health is influenced by three interrelated systems: o Biological: Genetic factors, immune system, physical constitution. o Psychological: Mental health, cognitive processes, personality structure. o Social: Environmental factors, society, family, relationships. Key Focus: This model recognizes the complex interplay between biological, psychological, and social factors in determining an individual’s health. 3. Risk Factor Approach (Pathogenetic Model) Focus: Identifies factors that increase the risk of disease or premature death. This model emphasizes the prevention of disease by addressing modifiable risk factors like smoking, poor diet, stress, and inactivity. o Non-modifiable Factors: Age, sex, family history, genetic predisposition. o Modifiable Factors: Physical activity, smoking, alcohol consumption, nutrition, stress management. Key Theoretical Implication: This model focuses on disease prevention by reducing known risk factors that lead to chronic illnesses (e.g., cardiovascular diseases, diabetes). 4. Salutogenic Model (Antonovsky, 1974) Salutogenesis: Focuses on health-promoting factors rather than the absence of disease. o Core Concept: The Sense of Coherence (SOC), which is a person’s ability to manage stress and maintain health in the face of challenges. o Components of SOC: § Comprehensibility: Understanding the world and life events. § Manageability: Belief that one has the resources to cope with challenges. § Meaningfulness: Feeling that life is worth living and that e]orts are worthwhile. Key Focus: Antonovsky’s theory aims to understand what makes individuals resilient to stress and how to improve health through life experience, rather than focusing on risk factors. 5. Social-Ecological Model Concept: Health is shaped by a combination of individual, social, environmental, and political factors. This model suggests that multiple levels of influence impact health outcomes and behavior, including: o Individual level: Personal factors such as knowledge, attitudes, and behaviors. o Interpersonal level: Relationships and social networks. o Environmental level: Access to resources, living conditions, and the built environment. o Political and Societal level: Government policies, societal norms, and the socio-economic environment. Application: This model suggests that interventions should target multiple levels (individual, social, environmental) to effectively promote health and physical activity. 6. Theories of Health Behavior Change Theory of Planned Behavior (TPB): o Focus: Predicts health behaviors based on attitudes, subjective norms, and perceived behavioral control. o Key Components: § Attitudes: Personal beliefs about the behavior. § Subjective Norms: Perceived social pressure to engage or not engage in the behavior. § Perceived Behavioral Control: Belief in one’s ability to perform the behavior. Self-Determination Theory (SDT): o Focus: The motivation behind choices people make without external influence and interference. o Key Components: § Autonomy: Feeling of being in control of one’s actions. § Competence: Feeling capable and e]ective in performing a task. § Relatedness: Feeling connected to others. Kurt Lewin's Field Theory: o Formula: V = f(P, U), where V (behavior) is a function of the interaction between the person (P) and the environment (U). o Key Idea: Behavior is influenced by both internal factors (e.g., personality, thoughts) and external factors (e.g., environment, social context). 7. Comparison of Health Models Risk Factor Model: o Focus: Health is explained by identifying and reducing risk factors, mainly biological/genetic or lifestyle-related. o Limitations: Does not consider psychosocial factors and coping strategies adequately. Salutogenic Model: o Focus: Health is promoted by enhancing individuals' ability to cope with stress and life challenges, focusing on psychosocial resources. o Key Theories: SOC, which focuses on resilience, self-e]icacy, and meaningfulness in life. 8. Determinants of Health and Exercise Performance Individual Level: Genetics, physical abilities, and personal behaviors (e.g., exercise habits, smoking). Social Level: Social support, cultural expectations, and social integration. Environmental and Political Level: Access to health resources, social policies, urban design, and environmental conditions. Internal and External Load 7 1. Tracking and Monitoring Overview Tracking and monitoring are critical tools in sports science to analyze athlete performance and well-being. These systems help in measuring physical and physiological parameters, enabling coaches to optimize training and performance. Monitoring can be performed using various tracking technologies, including video technology, GPS, and RFID systems, as well as physiological sensors like heart rate monitors. Key Types of Measurements: External measurements: Include distance, speed, accelerations, and decelerations. Internal measurements: Measure physiological parameters such as heart rate, lactate levels, and respiratory data. 2. Tracking Systems and Technologies Position Determination: o Via Video Technology: Used for tactical and technical analysis. o Via Satellite (GPS/GNSS): GPS systems are used to track speed, distance, and positioning in outdoor environments. o Radio-based Tracking (RFID): Utilized in environments like indoor arenas for precise tracking of athletes. Physiological Monitoring: o Heart Rate Monitoring: Tracks the athlete's cardiovascular response during physical exertion, such as HRmax and Heart Rate Variability (HRV). o Respiratory Monitoring: Includes tracking breathing frequency and oxygen saturation. Analysis and Visualization: o Technical and Tactical Visualization: Notation systems and video technology to analyze the technical aspects of performance, such as match analysis. o Team Management: Utilizes systems to monitor training loads, manage schedules, and optimize performance. 3. Validity and Reliability Validity: Refers to the accuracy of a measure, ensuring that the tool measures what it is intended to measure (e.g., a GPS system accurately tracking running distance). o Formula: Regression analysis and comparison with criterion measures.  Reliability: Refers to the consistency of a measure, ensuring that it gives similar results under consistent conditions. o Formula: Coe]icient of Variance (CV), Intra-Class Correlation (ICC), etc. Important Note: Different tracking technologies, such as GPS, may have varying degrees of validity and reliability, especially under different conditions like indoor vs. outdoor environments. 4. What Can We Measure? External Measurements (Objective): o Distance (total distance covered, distance per minute). o Speed (max speed, speed zones, acceleration, deceleration). o High Intensity Activities (sprints, jumps, high-intensity actions). o Metabolic Power (average watt per kilogram). Internal Measurements (Objective and Subjective): o Heart Rate (max HR, average HR). o Perceived Exertion (sRPE): Subjective measure of e]ort. o Lactate Levels: Measurement of metabolic stress during training. These metrics provide insights into the locomotive, mechanical, and metabolic demands of athletes, allowing coaches to tailor training loads and recovery periods. 5. Practical Application in Team Sports Tracking Individual Players: o Example: A training session where Player 1 (CD) covered 159 meters with a relative intensity of 2.0 m/min, and Player 2 (LB) covered 251 meters with a relative intensity of 3.1 m/min. Periodization: o Monitoring training load using acute-to-chronic workload ratios ensures that athletes do not experience overtraining or injury. o Microcycles and Mesocycles: Help structure the training to gradually increase intensity and volume over time. 6. Selecting Variables for Monitoring Choosing the right variables for measuring athletic performance and well-being is crucial. The selection depends on: Training goals (e.g., improving endurance, strength, or speed). Specific demands of the sport (e.g., measuring high-speed running in football vs. endurance in long-distance running). Internal vs. External Measurements: External variables provide an overview of the physical performance, while internal variables like heart rate provide insights into physiological strain. Thermoregulation 1. Overview of Thermoregulation Thermoregulation refers to the processes by which the body maintains its core temperature within a narrow range to ensure proper functioning. The core body temperature for humans typically ranges from 36.1°C to 37.8°C. These processes are regulated by both chemical and physical mechanisms, such as shivering for heat production and sweating for heat dissipation. Thermoregulatory Mechanisms: o Heat production: Shivering, muscular activity. o Heat dissipation: Radiation, conduction, convection, and evaporation (sweating). Extreme Conditions: o Hyperthermia: Core body temperature exceeding 40°C, leading to potential heat stroke. o Hypothermia: A drop in body temperature below 36°C, causing dangerous physiological changes. 2. Temperature Regulation Mechanisms Core Temperature Control: o The hypothalamus is the central regulator of body temperature, responding to inputs from thermal receptors in the skin and core. o Heat Dissipation: The body loses heat through radiation, convection, and evaporation. o Heat Production: Heat is produced through muscular activity, hormonal secretion, and the thermal eYect of food. Environmental Influence: o Temperature extremes (both cold and hot environments) pose challenges to thermoregulation. o The body adjusts its metabolic rate to maintain a stable temperature, utilizing shivering in cold and sweating in hot conditions. 3. Internal and External Influences on Thermoregulation Gender DiYerences: Research indicates that males and females may experience di]erences in thermoregulation, with males generally having higher core temperatures during exercise in the heat. Exercise Impact: During exercise, the body's core temperature increases due to metabolic heat production, while sweating increases to dissipate heat. Clothing and Insulation: Proper clothing helps regulate body temperature by influencing heat retention or dissipation, depending on the environment. 4. Thermoregulation in Extreme Environments Hot Environments: The body may become overheated if heat production surpasses heat dissipation, leading to conditions like heat exhaustion and heat stroke. Acclimatization strategies like pre-cooling (e.g., ice vests) can help improve performance and tolerance in the heat. Cold Environments: In the cold, the body uses vasoconstriction and shivering to conserve heat. Chronic exposure can lead to hypothermia if heat loss exceeds production. 5. Cooling Strategies Heat Acclimatization: Training in warm environments or using techniques like sauna sessions can help the body adapt to heat stress. Pre-Cooling: Cooling strategies before exercise (such as wearing cooling vests) help improve performance during subsequent physical exertion in hot conditions. Cooling Methods: Strategies such as ice slush ingestion or cooling vests can help reduce core temperature during recovery. 6. Practical Application Monitoring Core Body Temperature: During events like the 2019 World Championships in Doha, monitoring core temperature is crucial to prevent heat- related illnesses. Sweat Loss and Performance: Excessive sweat loss (over 2% body weight) can impair performance, as it leads to dehydration and reduced cardiovascular e]iciency. Change of Direction (Philipp Kunz) Terminology of Changing Direction Key Concepts: o Planning and Execution: Two distinct areas in movement o Perceptual Factors: Decision making o Changing Direction Speeds: Physiological execution of movement Intersection of both leads to Agility: o Agility encompasses perception, planning, decision making, and execution o Changing Direction Speed is a subset of agility, not synonymous with agility Influencing Factors of Agility (by Sheppard and Young) Change of Direction categorized into: o Technique o Straight Sprinting speed (SSS) o Anthropometry o Leg muscle qualities § Reactive strength, concentric strength and power, left-right muscle imbalance Perceptual & decision-making factors: § Anticipation § Pattern Recognition § Visual Scanning § Knowledge of Situations Focus for training today: Leg muscle qualities and SSS Anthropometry and Technique: o Not the focus as they are harder to influence through training Methodology in Studies Common approach: o Test athletes for changing direction ability and physiological factors o Measure the correlation between the two Straight Sprinting Speed Correlation with change of direction: o Moderate correlations found in studies (0.33 to 0.55). o Variables a]ecting correlation: Distance of sprint, angle/number of turns, type of athlete o Relationships between COD, Sprint, Jump and Squat Power Performance Reactive Strength Overview of meta-analysis (2023): o Negative correlation with changing direction speed (better reactive strength = faster speed).  o Reactive Strength Index (RSI) calculated through jumping metrics (jump height/contact time). Average correlation found: -0.42. Concentric Strength and Power Changing direction involves: o Deceleration to speed 0 (eccentric) and then re-acceleration (concentric). Most studies focus on concentric strength correlation due to insu]icient eccentric strength research Meta-analysis confirms moderate correlation (0.55). Eccentric Strength Not su]iciently covered in literature until recently: o New findings: high importance in change of direction ability (high force during deceleration) Muscle Imbalance Muscle power and imbalance as a predictor for change of direction speed: o Study indicated right leg dominance could impact performance due to imbalances o Need for more research and less consistent findings, no meta-analysis Conclusion No consistency in testing methods (strength/power (static vs. dynamic), straight sprinting, jumps) Di]erences between age groups, male/female, sports More research needed for eccentric strength (meta analysis) àCOD multifactorial ability àas S&C Coach specific research needed (sport, age, gender, etc.) Testing Methods Testing Parameters Tests for change of direction must consider: o Familiarization: Reduce learning e]ects on tests o Time under tension: Di]erent tests have varying e]ects o Number and angle of turns  Common Tests 1. Illinois Agility Test: o Appears misleading as it tests change of direction not agility o Time averages: Male ~16s, Female ~17.5s 2. 505 Test: o Simple change of direction (180-degree turn) o Time averages: Male ~2.5s, Female ~2.7s 3. T-Test: o Involves multiple directional changes o Time averages: Male ~10.5s, Female ~12s àResults: high intraday reliability, all tests assess same physical components àgood intra comparability of the tests, but there’s no gold standard Conclusion: Practical Recommendations Holistic training (sport specific) Additional training: influencing factors? Focus on athlete’s weaknesses! Don’t forget to decelerate! Testing COD: does test reflect my requirements?