Energy Systems

Energy Systems

Energy Systems for Exercise

Energy Systems Energy Systems

Immediate energy ATP-PC

Short-term energy Lactic acid system

Long-term energy Aerobic system

ATP-PCr System ATP-PCr System

ultra-short duration (< 6 seconds)

high intensity require an immediate and

rapid supply of energy 100-m sprint 25-m swim Smashing a tennis serve Thrusting a heavy weight

upwards

Lactic Acid SystemLactic Acid System

During performances of short duration and high intensity that require rapid energy transfer that exceeds that supplied by phosphagens 400-m sprint 100-m swim Multi-sprint sports

Anything up to 3 minutes Lactate is the by product “Lactic acid system’

Lactate Shuttling

Pyruvate Acetyl CoA

Citric acid cycle Oxidation =

removal + energy

Lactic Acid System Lactic Acid System

Blood lactate removal Gluconeogenesis-

conversion to glucose through Cori cycle in the liver

Oxidation to pyruvate Fuels citric acid cycle

Lactate Threshold

The exercise intensity prior to the abrupt increase in blood lactate A.k.a onset of blood

lactate accumulation (OBLA)

Lactate / Lactic AcidLactate / Lactic Acid

Terms: LACTATE AND LACTIC ACID Lactate production and accumulation in

muscle coincides with, rather than causing acidosis

DOMS incorrectly attributed to lactate build-up

Caused by damage to muscles not the pain from damaged muscle cells, but from

the reinforcement process- adding new sarcomeres (the segments in the muscle fibrils)

reinforcement process causes the cells to swell and put pressure on nerves and arteries, causing DOMS.

Aerobic Energy SystemAerobic Energy System

Duration > 2/3 minutes Lipids

Lipolysis Beta oxidation Kreb’s cycle

Carbs Glycolysis Pyruvate Acetyl CoA Krebs cycle (citric acid cycle or tricarboxylic acid cycle) Electron transport chain

Energy requirements at rest

Almost 100% energy comes from aerobic metabolism

Therefore blood lactate levels are steady and low (<1.0 millimoles p/L)

7- kg young adult consumes 0.25 L O2 p/min

Transition to Exercise

O2 consumption

Recovery

O2 consumption remains elevated

O2 Dept = payment for O2 deficit

Vo2 Max

Determines cardiovascular fitness

O2 uptake increases with intensity of exercise up until a certain point

ml/kg/minute Factors influencing:

Delivery uptake

Muscle Fibre Types

Type 1 = Slow twitch Generates energy aerobically For endurance exercise

Type 2 = fast twitch 2a- some aerobic power = anaerobic 2b-predominantly anaerobic

Generates energy anaerobically For short intense exercise

Implications

Recovery from exercise

Remove lactate Re-oxygenation muscle myoglobin Replace

Muscle glycogen PCr Lipid levels

Active recovery

Movement at a lower intensity/ submax performed immediately after exercise

Assists with oxidation of lactate (Lactate shuttling)

But may impair

glycogen synthesis

Passive recovery

Lie down complete inactivity

Theory is that this ‘frees’ oxygen for the recovery process

Which is best?

Research inconclusive Depends on exercise to recover from Steady rate exercise

PCr stores not depleted Lactate levels not increased Depends on post exercise glucose intake

Intense/Non-Steady rate exercise Large O2 deficit

Lactate Removal

Exercise Recovery

Passive

Active Passive

Training the Energy Systems

Training the ATP-PC system

4 to 7 seconds of high intensity work at near peak velocity are required e.g. 3 × 10 × 30 metres with recovery of 30

seconds/repetition and 5 minutes/set. 15 × 60 metres with 60 seconds recovery 20 × 20 metres shuttle runs with 45

seconds recovery

Training the anaerobic lactate system

5 to 8 × 300 metres fast - 45 seconds recovery - until pace significantly slows

150 metre intervals at 400 metre pace - 20 seconds recovery - until pace significantly slows

8 × 300 metres - 3 minutes recovery (lactate recovery training)

Training aerobic systems

4 to 6 × 2 to 5 minute runs - 2 to 5 minutes recovery

20 × 200m - 30 seconds recovery 10 × 400m - 60 to 90 seconds

recovery 5 to 10 kilometre runs

Chronic Adaptations to Training

Metabolic pathway Adaptation Consequence

Mitochondrialrespiration

Small May improve recovery

Glycogen Concentration Fuel for glycolysis

Glycolysis Activity ofphosphorylase

Rate of glycolysis

Activity of PFK Rate of glycolysis

ATP Small Tolerance of intenseexercise

Metabolic pathway Adaptation Consequence

Creatinephosphate

Small Capacity to rapidlyregenerate ATP

Buffering capacity Capacity Delays fatigue fromacidosis ATP from glycolysis

Summary

Immediate energyATP-PC Short-term energy Lactic acid system Long-term energy Aerobic system Dynamic balance Training Recovery