Glycolytic system

• Glycolytic energy system


  • Anaerobic glycolysis
  • Lactic acid system
• Glycolytic energy system


  • Most predominant energy system after first 10-12 secs of intense activity exhausts
  • Phosphocreatine (PC) stores and ATP levels fall
  • ADP levels rise again and trigger release of phosphofructokinase
  • Partial breakdown of glucose into pyruvic acid
• Anaerobic glycolosis


  1. Decrease in PC stores activates enzyme glycogen phosphorylase to break down glycogen into glucose

  2. Partial breakdown of glucose into pyruvic acid

  3. In absence of O2, pyruvate is converted into lactic acid
• Lactic acid system


  • 1 molecule of glucose produces 2 molecules of ATP
  • Lasts up to 3 minutes
• Glycolytic energy system components


  • Glycogen
  • Glucose
  • Pyruvic acid
  • Lactic acid
• OBLA


  • Onset of blood lactic accumulation
  • As lactic acid accumulates, hydrogen ions dissociate, leaving lactate
  • Responsible for acidity and feelings of pain as exercising limbs become heavy
  • Lactate blocks nerve signals
  • Performance drops rapidly