Sport Physiology A Flashcards
Define Energy?
The ability/capacity to perform work
(comes from breakdown of ATP)
What is ATP?
Adenosine Triphosphate
- The body’s energy “currency” for all body cells
- Serves as the immediate source of energy that comes from the breakdown of ATP
- Powers all the body’s metabolic activities
What is ADP?
Adenosine Diphosphate
- Is created when ATP splits to release energy
- Occurs when one of the three phosphate molecules splits off and energy is released
How many seconds worth of ATP is stored in body cells?
1-2secs (max)
Name the Energy Systems for Replenishing ATP
- Phosphate Creatine System (ATP-PC System)
- Anaerobic Glycolysis System
- Aerobic Glycolysis System
How is ATP resynthesised?
Through fuel/energy substrates and the energy systems
How much ATP is in our muscular systems?
50-100g
How much ATP is produced daily?
50-180kg - typically upwards of bodyweight
Where is Creatine Synthesised?
Liver, kidneys and pancreas
What is PC primarily used for?
The ATP-PC system (powerful movements)
How can Creatine be consumed?
Through diet
- Fish
- Meat
- Supplements
What are the 3 main fuels for our body?
Carbohydrates (carbs/CHOs)
Fats (lipids)
Proteins
What are CHOs?
Primary and most versatile source of fuel
- sugars and starches
- can be simple or complex carbs
- should make up 55-60% of diet/60-80% for athletes
What are CHOs transported as and how?
Glucose/glycogen and transported through the blood
What is glycogen/glucose?
Broken down carbs and/or released by liver to be used for energy (ATP) production
Where are CHOs stored?
- Blood
- Muscles and liver (glycogen)
- Excess stored as fat (adipose tissue around body)
What are CHOs stored as?
Glucose, glycogen or adipose tissue
Low GI Foods
0-55 GI
Slow release of energy providing a constant source
- pasta
- oats
- brown bread
Medium GI Foods
55-79 GI
- bananas
- mangoes
High GI Foods
79-100 GI
Instant energy from rapid increase in blood sugar levels
- white bread and rice
- energy drinks
- jelly beans
What is the role of the Energy Systems regarding ATP?
Serves to replenish stores of ATP through phosphorylation
(ADP + Pi + energy –> ATP)
What are fats?
- Extremely high source of energy
- Supply the “most” energy but harder to break down
- Made of free fatty acids (FFA) and triglycerides
- Should make up 20-30% diet
How are fats transported?
Broken down and transported through blood as FFA
How is fat stored?
Adipose tissue
FFA
Triglycerides
Where is fat stored?
Around the body (as adipose tissue)
Liver
Muscles
Blood
When are fats used as the predominant energy source?
During low intensity/sub-maximal efforts
When carbohydrate stores are depleted
What are proteins?
Amino acids that are essential for growth, repair and recovery of body tissue
Are the emergency fuel source when both carb and fat stores are depleted
How can protein be consumed?
Meat, fish, eggs, diary
In extreme situations protein is released from breakdown of body tissue
How are proteins transported?
As amino acids in the blood
How are proteins stored?
Body tissue/muscle
Body fluids
Adipose tissue
What is hitting the wall?
An individuals sudden increase in fatigue and decrease in power
How does hitting the wall occur?
When liver and muscle glycogen stores become depleted
Fats become the primary source of energy to produce ATP (as oxidisation is slower)
How to counteract hitting the wall?
Carb loading
Consuming high GI fuel sources during the race
Glycogen sparing
What is glycogen sparing?
An athletes increased capacity to metabolise on fats to rely on less and hence save glycogen stores
Glycogen is not used on early in an event, so there is an increased capacity to use fats through an improved oxidisation ability
Energy from ATP
Is limited in storage
ATP splitting releases energy
Different fuel substrates resynthesise ATP depending on intensity and duration of activity
ATP Production: Rest
Produced aerobically as high O2 abundance
2/3 of ATP produced comes from the breakdown of fats
Fats breakdown when abundant O2 is available
ATP Production: Initially
ATP is produced anaerobically as respiratory and circulatory systems cannot meet demands to supply O2 to working muscles
ATP Production: Anaerobic
Produce ATP for powerful and quick movements
Limited amounts of ATP–> limited activity time
Fatiguing by-products (Lactic Acid)
ATP Production: Aerobic
Produce ATP for prolonged periods
Cannot produce energy quickly for high intensity efforts only sub-maximal/low intensity
Non-fatiguing by-products
What is Phosphorlyation?
Chemical addition of a inorganic phosphate back onto ADP to synthesise ATP
What is the Phosphagen System?
ATP-PC system (anaerobic)
Provides the bulk of ATP for powerful/explosive/short efforts \
Relies on stores of ATP and PC
Lasts 10-12secs
How does PC resynthesise ATP?
Stored ATP lasts for 2 seconds
PC splitting can provide energy to resynthesise ADP to ATP
How long does it take for the ATP-PC system to recover?
3-5mins to restore to pre-exercise levels
- 50% PC replenishment occurs in first 30s
- <10s of effort only 3mins to recover
What is the Anaerobic Glycolysis System?
Known as the lactic acid system
ATP is produced via incomplete breakdown of glucose
Provides for bulk of ATP for high intensity/maximal activity for exercise longer than 10s
Relies on muscle stores of glycogen and blood glucose
Produces pyruvate acid and H+ ions
Sporting Example: ATP-PC
100m sprint
Sporting Example: LA
400m sprint
LA Sytem: By-products
Fatiguing (lactic acid from incomplete breakdown of pyruvate and hydrogen ions)
Aerobic System: By-products
Non-fatiguing (H2O, CO2 and heat)
How does Lactic Acid Accumulate?
Through the incomplete breakdown of pyruvic acid
In aerobic system O2 in mitochondria facilitates breakdown
As no O2 in anaerobic system, pyruvate is unable to breakdown and is converted to LA
How is Pyruvic Acid produced?
Via the incomplete breakdown of glucose
What are the impacts of LA and H+?
Accumulate in the muscle cells during prolonged high intensity efforts
Result in a decrease of blood pH (increased acidity) and cause soreness burning/tiredness
Body can tolerate until Lactic Threshold is met (production is higher than removal rate)
Lactic Acid Removal/Fate
65% converted to CO2 and H2O
20-25% into muscle/liver glycogen
10% protein
5% glucose
How long does the LA last?
2-3mins
Duration of Energy Systems
ATP-PC: 0-12s
LA System:
Aerobic System:
What is the Aerobic System?
Uses O2 to drive the production of ATP via the breakdown of carbs, fats, and proteins
Process occurs in the mitochondria
What are the three main stages of the Aerobic System?
- Anaerobic glycolysis
- Krebs Cycle
- Electron Transport Chain
Order of fuel substrates in the Aerobic System
- Carbohydrates (glycolysis)
- Fats (lipolysis)
- Proteins
Anaerobic Glycolysis
- Occurs in the muscle cell
- Carbs are the prominent fuel source
- Glycogen is broken down to form glucose which is broken down to form pyruvic acid
- This releases a small amount of ATP
Krebs Cycle
- Occurs in the mitochondria
- O2 and fuel (glucose, protein, fats and pyruvic acid) enter
- O2 combines with carbon (CO2 waste product
- H+ ions are produced
- Some ATP is released
Electron Transport Chain (ETC)
- Occurs in the mitochondria
- H+ and water combine (H2O as waste product)
- Heat is produced
- Large amount of ATP (energy is released)
What is myoglobin?
An oxygen binding protein found in skeletal muscle cells that attracts O2 from the blood stream to muscle cells
What is the function of myoglobin?
To aid the delivery of O2 from the cell membrane to the mitochondria
When O2 conc is low, it will release O2
How is O2 transported around the body?
Via haemoglobin in blood to the capillary beds on muscle where it is released and diffuses into muscle cells
How to increase O2 utilisation?
Aerobic training increases the body’s ability to attract O2 from blood to muscle cells
Three physiological adaptations that increase O2 utilisation
- Increased number and size of mitochondria
- Increased myoglobin stores
- More capillaries
Define Energy Continuum/Interplay
The continual interplay between all energy systems to meet energy demands based upon the type, intensity and duration of activity
What are the three factors the determine the dominant energy system?
Fitness Level
Intensity
Duration
Types of Muscle Fibres
Slow Twitch (Type 1)
Fast Twitch (Type 2a & 2b)
Colour of Fibres
Type 1: Red (rich O2/blood supply)
Type 2a: Pink (combination)
Type 2b: White (limited 02/blood supply)
Fatigue resistance of Muscle Fibres
Type 1: high
Type 2a: medium
Type 2b: low
Strength of Contraction of Muscle Fibres
Type 1: slow
Type 2a: fast
Type 2b: fastest
Characteristics of Muscle Fibres
Type 1: aerobic
Type 2a: aerobic and anaerobic
Type 2b: anaerobic
Mitochondria density of Muscle Fibres
Type 1: high
Type 2a: moderate
Type 2b: low
How to improve Muscle Fibres?
Specific aerobic/anaerobic training
Own fibres influenced by genetics
What fuel substrate produces the most energy?
Fats - 12x more ATP produced than carbs
Increased Heart Rate
Heart pumps faster to supply more O2 to working muscles
Measured in BPM
MHR 220 - age
Stroke Volume
Volume of blood ejected from the left ventricle per beat
3 Factors that affect Stroke Volume
Frank-Starling Mechanism
- increased blood returning to heart results in stronger contraction of left ventricle ∴ increased SV
Neural Stimulation
- increased nerves increase SV
Peripheral Resistance
- resistance to passage of blood
Cardiac Output
Volume of blood pumped by the heart per minute (mL blood/min)
Q = SV x HR
Blood Pressure
Pressure exerted by the blood against the arterial walls as it forced through the circulatory system by the heart
2 main components: systolic and diastolic
Measured by systolic/diastolic e.g 120/80
Systolic Blood Pressure
Higher value of the two
Pressure recording while contracting
Diastolic Blood Pressure
Lower value of the two
Pressure recording while relaxing
Blood Redistribution
Redistribution of blood from organs to muscles during exercise
Achieved through vasodilation and vasoconstriction of blood vessels
Systemic Blood Flow
Blood flow around the body
At rest 15-20% to muscles - rest to organs (vasoconstriction)
At exercise 80-90% to muscles - rest to organs (vasodilation)
Vasoconstiction
Capillaries and arterioles restricting blood flow
Component of blood redistribution
Vasodilation
Capillaries and arterioles expanding
Component of blood redistribution
Arteriovenous Oxygen Difference (A-VO2 Diff)
Difference in the conc of O2 in the arterial blood and conc of O2 in the venous blood
Measured in ml/100mL of blood
External Respiration
gas exhange at the alveoli
Internal Respiration
gas exchange at the muscle fibres
Respiratory Rate
Number of breathes per min
Increases during exercise
Tidal Volume
The amount of air inhaled and exhaled in a breathe
Increases during exercise
Pulmonary/Minute Ventilation
Volume of air moved in and out of the respiratory tract per min
VE = RR x TV
Gas Exchange
Replenishment of O2 and removal of CO2
Occurs at lungs and muscle tissue (external and internal respiration)
O2 Uptake/VO2
Amount of O2 transported to, taken up, and used by the body for energy production
Increases during exercise due to muscles need for O2
Oxygen Deficit
Shortfall (discrepancy) between oxygen supply and demands for exercise, where ATP must be produced anaerobically
Aerobic Steady State (ASS)
The state of which oxygen supply meets oxygen demands and virtually all ATP is produced aerobically
Trained athletes can reach ASS quicker due to increased myoglobin and haemoglobin stores
Usually 60-85% MHR
EPOC
Excess Post-Exercise Oxygen Consumption
What is EPOC?
After cessation of exercise, oxygen uptake/consumption remains elevated about normal levels
VO2
Amount of O2 per minute transported by, taken up and used by the body to produce energy (ATP)
VO2 Max
Max amount of O2 per minute transported by, taken up and used by the body to produce energy (ATP)
or
The highest rate of oxygen consumption attainable during maximal or exhaustive exercise
Types of VO2
Absolute
Relative (bodyweight)
Absolute VO2
Expressed in L/min
Does not factor body weight ∴ less comparable
Divide by bodyweight to find relative value
Relative VO2
Expressed in mL/kg/min
Factors body weight ∴ quantifiable and comparable
Times by bodyweight to find absolute value
Factors that influence an individual’s VO2 (5)
- Aerobic Fitness
- Body Size
- Gender
- Heredity
- Age
Lactate Threshold Point (LIP)
The point beyond the intensity of an effort cannot be maintain by an athlete
Beyond this point LA accumulation is greater than its removal ∴ causing fatigue
Why is LIP important?
Athletes can exercise at a higher intensity for longer before fatigue sets in
Is a better indicator of aerobic performance than VO2 Max
Buffering
Utilising lactate to assist in neutralising H+ and remove lactate to improve performance after LIP is reached (CHECK)
e.g bi-carb soda
What are Acute Responses?
The immediate changes the body experiences in response to exercise that only last for entirety of exercise
LIP VALUES (Trained and Untrained athletes)
Untrained: 60% MHR or 70-80% VO2 Max
Trained: 90% MHR or 70-80% VO2 Max (CHECK THIS)
Acute Cardiovascular Responses (7)
Increased HR
INcreased SV
Increased BP
Increased A-VO2 Dif
Increased Cardiac Output (Q)
Increased blood flow
Blood Resdistribution
Acute Respiratory Responses (4)
Increased RR
Increasde TV
Increased minute ventilation
Increased O2 uptake (VO2)
Acute Muscular Responses
Increased O2 supply and usage
Increased muscular temp
Increased blood flow to muscles
Depletion of muscle energy stores (ATP, PC, glycogen, triglycerides)
What are Chronic Adaptations?
The long-term physiological adaptations the body makes to training over an extended period (6-8 weeks)
Factors that affect the nature of Chronic Adaptations (4)
- Genetics and Fitness Capacity
- Frequency, Duration and Intensity
- Anaerobic/Aerobic Training
- Type and Method of Training
Cardiac Hypertrophy
Is the enlargement of the heart based on aerobic or anaerobic training
Endurance/aerobic athletes will have a bigger left ventricle
Power/anaerobic athletes will have an bigger heart wall
enlargement of the heart chambers (especially the left ventricle) and thickening of the myocardium (heart muscle) as a result of training.
Chronic Circulorespiratory Adaptations (REST) (7)
Decreased resting HR
Cardiac Hypertrophy
Increased SV
Decreased BP
Increased blood volume and haemoglobin
Unchanged/decreased cardiac output
Increased capillarisation of heart and skeletal muscle
Chronic Circulorespiratory Adaptations (SUB-MAX) (7)
Decreased HR
Cardiac Hypertrophy
Increased SV
Decreased BP
Increased A-VO2 Dif
Improved HR recovery rates
Decreased minute ventilation
Chronic Circulorespiratory Adaptations (MAX) (5)
Cardiac Hypertrophy
Increased SV
Increased cardiac output
Improved HR recovery rates
Increased minute ventilation
Chronic Muscular Adaptations (Endurance) (8)
Increased O2 utilisation
Increased myoglobin conc
Increased size/number of mitochondria
Increased size of slow twitch fibres
Increased oxidisation of CHOs and fats
Glycogen sparing - increased oxidisation of fats
Increased ATP-PC stores
Increased sotres of muscle glycogen/triglycerides
Chronic Muscular Adaptations (Non-Endurance)
Increased glycogen stores
Increased ATP-PC stores
Increased flexibility
Increased size of fast twitch fibres
Increased number of muscle capillaries
