Ch.7-Energy for Muscular Activity

Question 1

Energy fort Muscular Activity

Answer 1

Muscles contraction requires energy
Must be sufficient: amount and rate
3 energy systems with different amounts and rates

Question 2

Chemistry of Energy Production

Answer 2

ATP=Adenosine triphosphate

Question 3

Chemistry of Energy Production

Answer 3

Adenosine Triphosphate (ATP): Fuel’s all biochemical processes. Body’s energy currency
Hydrolysis: ATP->Adenosine Diphosphate (ADP) + free phosphate. Energy liberated for muscle contraction
ATP resynthesis: ADP+P->
Energy from breakdown of carbohydrates, protein and fat

Question 4

3 Energy Systems

Answer 4

Immediate energy: Phosphagen system
Short-term energy: Glycolytic system
Long-term: Oxidative system

Question 5

Immediate Energy: Phosphagen system

Answer 5

Anaerobic Alactic System
Creatine phosphate (CP): Broken down to P. Combines with ADP. 1 ATP.
Small amounts of muscle CP and ADP stored.

Short duration, very high intensity activities. Eg: sprint

Question 6

Phosphagen system: Characteristics

Answer 6

1. Large amounts energy produced in a short time
2. Fast recovery
   Requires sufficient local supply of CP. Small and depleted rapidly

Rest and recovery needed quickly. 7-12s @very high intensity. 15-30s @moderate intensity.

Question 7

Short-Term Energy: Glycolytic System

Answer 7

Anaerobic Lactic System.
Glycolysis: Glucose breakdown to 2 ATP’s. w/ enzymes, without oxygen.

1. High rate:pyruvic acid->lactic acid (anaerobic)
2. Low rate:pyruvic acid->pyruvate(aerobic)

Carbohydrates: Primary source of blood glucose. From pasta, breads,fruits,vedgetables.

Question 8

Glycolytic System Characteristics

Answer 8

Supports high intensity activities.
Lactic acid=painful and fatiguing by-product. Converts to lactate and hydrogen ions. Hydrogen ions cause muscle “burn” and diminish contraction. Lactate metabolised in heart, liver and muscles

Question 9

Effects of Training

Answer 9

Endurance training: Higher anaerobic threshold.
Muscle “burn” felt at higher intensity.
Faster removal of lactic acid: Higher muscle blood flow (higher capillaries, higher cardiac output). higher flow of lactic acid from muscles to blood. Higher metabolism of lactate.

Question 10

Long-term Energy: Oxidative System

Answer 10

Aerobic system
Oxidative phosphorylation: Carbohydrate, protein, fat–> many ATP. Muscle mitochondria w enzymes and coenzymes.
Most important, broad range of activities: Low/moderate intensities. <anaerobic threshold. Low lactic acid levels.
Requirements: 1. Enough muscle mitochondria.
2. Sufficient oxygen supply
3. Enzymes and intermediate by-products under control

Question 11

Long-term Energy:Oxidative System

Answer 11

Oxygen transport: Lungs->circulation->muscle. More ATP need= more oxygen delivery (linear):
more ventilation, more oxygen blood uptake, more oxygen muscle uptake.

Maximal aerobic power (VO2 max): Maximal rate of oxygen that can be consumed. Additional energy produced anaerobically.