Understanding Muscle Stiffness After Exercise

Introduction

• Explanation of why muscles feel stiff after exercise.
• Interactive experiment: Stretch and clench your left hand throughout the explanation.

Muscle Respiration

Aerobic Respiration

• Muscles need energy from respiration to contract.
• Aerobic Respiration: Requires oxygen to produce energy.

Anaerobic Respiration

• Occurs when muscles can't get enough oxygen during heavy exercise.
• Anaerobic Respiration: Does not require oxygen.
  • Less efficient: Produces less energy compared to aerobic respiration.
  • Produces lactic acid as a waste product.

Effects of Anaerobic Respiration

• Lactic acid buildup in muscles causes pain (e.g., arm aching during the experiment).
• Continuous exercise leads to increased lactic acid, causing muscle pain.

Post-Exercise Recovery

• Stopping exercise doesn't instantly remove lactic acid.
• Lactic acid travels to the liver via blood to be broken down into carbon dioxide and water using oxygen.
• Heavy breathing after exercise supplies oxygen needed to break down lactic acid (oxygen debt).

Muscle Stiffness

• Lactic acid accumulation causes stiffness in muscles post-exercise.
• Lack of movement post-exercise prevents lactic acid clearance, leading to next-day stiffness.
• Importance of warming down: Gentle jogging and stretching help lactic acid breakdown and reduce stiffness.

Conclusion

• Understanding lactic acid's role in muscle stiffness emphasizes the need for proper post-exercise routines.