Theory and Models Summary 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 diXerence) § 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.