wells psl 303 lecture 1. intro to energy systems physiology
DESCRIPTION
Sport Science, Exercise Physiology, Energy Systems, Aerobic, Anaerobic, PhosphagenTRANSCRIPT
PSL 303 Advanced Human Physiology Energy Physiology Overview
Greg D. Wells, Ph.D.
The University of Toronto www.per4m.ca
All Slides © Greg D. Wells, Ph.D. (2009), All Rights Reserved Web: www.per4m.ca Email: [email protected] Tel: 416-710-4618
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Class Agenda
• Neuromuscular Review • Energy Systems Overview • Aerobic Metabolism and Training • Anaerobic Metabolism and Training • High Energy Phosphate Metabolism and Training
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Neuro-Muscular Review
4
Neuro-Muscular Review
5
Neuro-Muscular Review
6
ATP: The Muscle’s Energy Source
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ATP: Sources via nutrition
• ATP is provided via: – Initial intra-muscular stores of ATP & PCr – Anaerobic breakdown of glycogen & glucose (CHO’s) – Aerobic oxidation of fats & carbohydrates
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Energy Systems Overview
• 3 Energy Systems – Aerobic – Anaerobic – High Energy Phosphate
• Purpose: To supply sufficient ATP at the rate that is required to perform the event.
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Energy Systems Overview
• 3 Energy Systems – Aerobic Slow – Anaerobic Medium – High Energy Phosphate Fast
• Purpose: To supply sufficient ATP at the rate that is required to perform the event.
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Energy Systems Overview
• 3 Energy Systems – Aerobic Slow Long
– Anaerobic Medium Medium – High Energy Phosphate Fast Short
• Purpose: To supply sufficient ATP at the rate that is required to perform the event.
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Ener
gy/P
ower
Out
put
Time 10 s 30 s 60 s 3 min 15 min+
Low power Very high capacity Time to peak power (~180s) Peak power (~3 – 5min) Power capacity (extensive / hours)
© S. Esau, University of Calgary
Energy Systems: Aerobic Oxidative
Krebs Cycle
32 ATP
Mitochondria
Aerobic Oxidation
Blood (capillaries)
Blood Glucose
Glycogenolysis / Gluconeogenesis
4 ATP
Anaerobic Glycolysis
Pyruvate
Lactic Acid Acetyl-CoA
ATPase
Creatine Kinase
Muscle (myofibres)
Fat Metabolism &
ß-Oxidation Protein Metabolism
© Greg D. Wells, Ph.D. (2008)
Ener
gy/P
ower
Out
put
Time 10 s 30 s 60 s 3 min 15 min+
High Power Limited Capacity Time to peak power (~8s) Peak power (~40 – 70s) Power capacity (~90 – 120s)
© S. Esau, University of Calgary
Energy Systems: Anaerobic Glycolytic
Krebs Cycle
32 ATP
Mitochondria
Aerobic Oxidation
Blood (capillaries)
Blood Glucose
Glycogenolysis / Gluconeogenesis
4 ATP
Anaerobic Glycolysis
Pyruvate
Lactic Acid Acetyl-CoA
ATPase
Creatine Kinase
Muscle (myofibres)
Fat Metabolism &
ß-Oxidation Protein Metabolism
Anaerobic Glycolysis
Fibre Utilisation as a Function of Intensity
© Greg D. Wells, Ph.D. (2008)
© Greg D. Wells, Ph.D. (2008) Web: www.per4m.ca Email: [email protected] Tel: 416-710-4618
Lactate vs. Ventilation
Ener
gy/P
ower
Out
put
Time
ATP-CP
10 s 30 s 60 s 3 min 15 min+
Very high power Very low capacity Time to peak power (ms) Peak power & capacity (~7 – 10s?)
© S. Esau, University of Calgary
Energy Systems: High Energy Phosphate
Krebs Cycle
32 ATP
Mitochondria
Aerobic Oxidation
Blood (capillaries)
Blood Glucose
Glycogenolysis / Gluconeogenesis
4 ATP
Anaerobic Glycolysis
Pyruvate
Lactic Acid Acetyl-CoA
ATPase
Creatine Kinase
Muscle (myofibres)
Fat Metabolism &
ß-Oxidation Protein Metabolism
Sport Science Application
• Monitoring of ATP / PCr depletion by cycle rate (strokes or cycles or strides / min)
Canada 4 x 100 m Relay 1996
© Greg D. Wells, Ph.D. (2008)
© Greg D. Wells, Ph.D. (2008)
© Greg D. Wells, Ph.D. (2008)
Pi
pH
PCr ATPy ATPa ATPb
MRI & MRS Results at Rest
At Rest After Exercise
4.3*105 2.9*105
1.2*105
0.4*105
pH: 7.15 pH: 6.75
© Greg D. Wells, Ph.D. (2008)
CP Metabolism
16-32 mmol /kg stored PCr (CP)
ATP Metabolism
7-10 kcal / mol ATP
4-8 mmol /kg of stored ATP
© Greg D. Wells, Ph.D. (2008) Web: www.per4m.ca Email: [email protected] Tel: 416-710-4618
ATP &Pcr Recovery Time
During chemiosmosis in eukaryotes, H+ ions are pumped across an organelle membrane into a confined space (bounded by membranes) that contains numerous hydrogen ions. The energy for the pumping comes from the coupled oxidation-reduction reactions in the electron transport chain. Electrons are passed from one membrane-bound enzyme to another, losing some energy with each transfer (as per the second law of thermodynamics). This "lost" energy allows for the pumping of hydrogen ions against the concentration gradient (there are fewer hydrogen ions outside the confined space than there are inside the confined space). The confined hydrogen cannot pass back through the membrane. Their only exit is through the ATP synthesizing enzyme that is located in the confining membrane. As the hydrogen passes through the ATP synthesizing enzyme, energy from the enzyme is used to attach a third phosphate to ADP, converting it to ATP.
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Characteristic High energy phosphate Anaerobic glycolytic Aerobic oxidative Fuel source(s) stored ATP,
phosphocreatine (PCr) stored glycogen, blood
glucose glycogen, glucose, fats,
proteins Enzyme sytem used in breakdown
ATPase HK, PFK, LDH, PDH, others
CS, MDH, SDH, others
Muscle fibre type(s) recruited
Type I, Type IIa, Type IIb
Type I, Type IIa, Type IIb
Type I, Type IIa
Power output requirement
high moderate - high low - moderate
Metbolic byproducts ADP, P, Cr lactic acid CO2, H2O maximum rate of ATP production (mmol/min)
3.6 1.6 1
Time to maximal ATP production
1 sec 5-10 sec 2-3 min
Maintenance time of maximal ATP production
6-10 sec 20-30 sec 3 min
Time to exhaustion of system
12-15 sec 45-90 sec theoretically unlimited
Ultimate limiting factor(s)
Depletion of ATP / PCr stores
Lactic acid accumulation
Depletion of carbohydrate stores, insufficient oxygen, heat accumulation
Time for total recovery (sec)
3 min 1-2 hr 30-60 min
Time for one half recovery (sec)
20-30 sec 15-20 min 5-10 min
Relative % ATP contribution to efforts of 10 sec
50 35 15
Relative % ATP contribution to efforts of 30 sec
15 65 20
Relative % ATP contribution to efforts of 2 min
4 46 50
Relative % ATP contribution to efforts of 10 min
1 9 90