Adaptations to Endurance and Resistance Training

Primary Adaptations to Endurance Training

• Increased Capillary Density
  • Enhances the delivery of oxygen and nutrients to muscle cells.
  • Improves waste removal from muscles.
• Increased Mitochondrial Biogenesis
  • Leads to improved oxidative phosphorylation.
  • Essential for better ATP production, impacting overall endurance performance.

Training Zones and Adaptations

• Training in Different Heart Rate Zones
  • Zone 5 or Zone 1 training both elicit the same crucial adaptations for endurance.

Role of AMPK in Endurance Training

• AMP-activated Protein Kinase (AMPK)
  • Acts as a central energy sensor during endurance training.
  • Activated by low energy levels, improving fuel burning capabilities.
  • Higher AMPK activity correlates with fasted states, indicating lower ATP levels.
• Krebs Cycle and Electron Transport Chain (ETC)
  • Enhanced mitochondrial biogenesis improves the efficiency of the Krebs cycle and ETC, thereby boosting ATP synthesis.

Chasing VO2 Max Improvement

• VO2 Max
  • Represents maximal oxygen uptake.
  • Improved through increased capillary density and mitochondrial biogenesis.

PGC-1 Alpha: Master Regulator of Mitochondrial Biogenesis

• PPARGC1A (PGC-1 Alpha)
  • A transcriptional coactivator that regulates genes involved in energy metabolism.

Nutrition: Fasting versus Fed States

• AMPK Activation and Nutritional States
  • Higher phosphorylated AMPK indicates a fasted state, while lower indicates a fed state.
  • Insulin inhibits AMPK activity, linking glucose consumption to energy state.
• Carbohydrates
  • Primary macronutrient that shifts the body from a fasted to a fed state.
  • Absence of carbohydrates can induce a therapeutic fasting state.

Resistance Training Adaptations

• Muscle Adaptivity
  • Muscle does not distinguish between types of training; adapts based on force applied and calcium ions managed.
• One-RM Definition
  • One repetition maximum (1RM) is the maximum weight you can lift through a complete range of motion.
  • Not the maximum force produced, as it requires dynamic movement.
• Intensity and Percent of One-RM
  • Resistance training intensity is often described as a percentage of 1RM.

Neural Adaptations in Beginners

• Neurological Adaptations
  • First adaptations to resistance training often involve improvements in neural tuning and recruitment.
  • Beginners can often see significant increases in strength due to improved motor patterning rather than muscle hypertrophy.

Types of Muscle Adaptation

• Muscle Endurance and Hypertrophy
  • Muscle endurance focuses on the ability to perform repeated contractions over time with submaximal loads.
  • Hypertrophy (increase in muscle size) defined by an increase in cross-sectional area of muscle fibers.
  • Occurs predominately through adding sarcomeres in parallel.

Bone Health and Resistance Training

• Wolff's Law
  • States that bones adapt to the loads under which they are placed, increasing bone density where loads are applied.
• Importance of Loading
  • Strength training (squats, deadlifts) is essential for improving bone health; must be at high intensity to stimulate bone remodeling.
• Risk of Hip Fractures
  • Aging individuals often face severe risks following a hip fracture, emphasizing the need for preventive resistance training.

Conclusion: Takeaways

• Endurance and resistance training both invoke a series of physiological adaptations that improve performance and health.
• Understanding these concepts can optimize training regimens and nutritional strategies for improved fitness outcomes.
• Focus on varying intensities and loads to target different adaptive responses in both muscle and bone.