Energy Systems - Unit 4

3 Energy Systems Fuel the Muscles

• All energy in the body is derived from the breakdown of:

  • Carbohydrates

  • Fats

  • Proteins

• The breakdown makes ATP (adenosine triphosphate)

ATP

• ATP is broken down into ADP and Phosphate (P)

• Used as energy for working muscles

• Allows actin and myosin to do their work

• ATP is continually resynthesized

  • With more food

3 Energy Systems

The energy systems work together to release energy at different rates

Energy System #1: Anaerobic Alactic

Supplies: High Power Output Activities

• Weight Lifting, sprinting,

• Immediate high rate of energy production

• Creatine Phosphate in muscles is used

• The Phosphate is used to bond with ADP to make quick ATP

• Produces a very high amount of energy for a really short duration

• Runs-out when Creatine Phosphate stores run out.

• High Intensity for 12 seconds

• Medium Intensity for 30 seconds

• Type 2 (fast twitch muscle fibres) contain a higher concentration of Creatine Phosphate

Energy System #2: Anaerobic Lactic

• Provides ATP for muscular work at high intensities

• 30 seconds to 5 minutes

• Breakdown of stored carbohydrates (glycogen)to make ATP

• Uses glycolysis and produces pyruvic acid to be used by the mitochondria

• If the mitochondria cannot process pyruvic acid fast enough, lactic acid will be produced

• Lactic Acid will produce Hydrogen ions (H*)

• Hydrogen ions hamper the function of the neuromuscular junctions (create muscle fatigue = muscle burn)

Anaerobic Threshold

• Exercise intensity where lactic acid begins to accumulate in the blood

• Discomfort and burning

• The rate of lactic acid buildup can be decreased by decreasing the intensity (allowing the mitochondria to use up the excess)

Endurance Athletes

• Remove lactic acid from muscles faster

• Have more blood flow in their muscles

• More exercise at higher intensities for longer

Ultramarathon

Energy System #3: Aerobic

• Used for a large range of activities

• Low intensity and low lactic acid levels

• 10 minutes to hours

• Endurance type activities

  • Long distance running, swimming, biking

• The mitochondria use food, water and oxygen to make ATP

• Uses the Krebs cycle and the ETC (electron transport chain)

• Makes large amount of ATP

Endurance Training

• Increased blood flow which delivers more nutrients and oxygen

• Increases number and size of mitochondria

The Oxygen Difference

System 1 alactic: 1 ATP per glucose

System 2 lactic: 2 ATP per glucose

System 3 aerobic: 36 ATP per glucose

VO2max - Maximal Aerobic Power

• Maximum rate of oxygen that can be consumed to make energy in muscles

• VO2max peaks at age 25

Working Together

The systems overlap and work together to provide energy at different intensities over different durations