Kinesiology - Energy Systems

Tonic Muscles

Muscles that assist the body with maintaining posture or stability
standing, walking, throwing
Contain many type I muscle fibers
(i.e. soleus muscle - helps with body posture)

Phasic Muscles:

Muscles that contain more type IIA and IIB
(i.e. biceps - key muscle for lifting and power)

As we age...

- decrease our fast twitch fibers and increase our slow twitch fibers
- changes our body composition
- increases our risks of falling

Type IIB

Fast-Glycolytic (FG)
Store glycogen and high levels of enzymes
Allow for quick contraction without the need for oxygen

Type IIA

Fast-Oxidative Glycolytic (FOG)
Intermediate-type muscle fibres
Allow for high-speed energy release
Allow for glycolytic capacity

Type I

Slow-Oxidative (SO)
Generate energy slowly
Fatigue-resistant
Depend on aerobic processes

Slow-Twitch Muscles are most active during:

long-distance running, swimming, and cycling

Slow-Twitch Muscles (colour)

Red or dark in colour

Slow-Twitch Muscles (general info)

Generate and relax tension slowly; able to maintain a lower level of tension for long durations
Low levels of myosin ATPase and glycolytic enzymes
High levels of oxidative enzymes
Have lots of Myoglobin - oxygen storage unit that delivers oxygen to working muscles

Fast-Twitch Muscles are using during:

short sprints, powerlifting, and explosive jumping

Fast-Twitch Muscles (colour)

Pale in colour

Fast-Twitch Muscles (general info)

Ability to tense and relax quickly; generate large amounts of tension with low endurance levels
High levels of myosin ATPase and glycolytic enzymes

This type of muscle can change into another one

Type IIB can transform into type IIA with aerobic endurance training

What do myosin ATPase and glycolytic enzymes do?

Permit release of glycogen in muscles

Cori Cycle

Gluconeogenesis
Most lactic acid is transported to the liver to be converted back to glucose/glycogen
Lactic acid is converted to pyruvate, then glucose, then glycogen

Trying to delay LA Buildup is trying to delay which process?

Glycolysis

What does a sprinter aim to do and how?

- aims to work harder/longer in the ATP-PC system
- Work in short intervals (up to 90 sec)
- increase CP stores in the muscle fibers
- increase glycogen stores
- increase the ability to convert glucose to glycogen quickly

What does an endurance athlete aim to do and how?

- aims to work harder/longer in the aerobic system
- Work in longer intervals (more than 2 min)
- increase oxygen-processing capabilities of lungs/blood/muscles
- increase # of mitochondria + oxygen-storing myoglobin molecules

VO2 max or BLT as an indication of fitness level leading to performance?

BLT is a better indication of fitness level leading to performance compared to VO2 max as it is largely hereditary

Anaerobic training to raise BLT

- short intervals
- delays the onset of LA build-up by training at or just above BLT heart rate

Aerobic training to raise BLT

- long intervals
- improves cardiorespiratory capacity
- increases mitochondria and myoglobin in the muscle fibres
- improves the efficiency of oxygen transfers in the cell

Levels of BLT in untrained individuals compared to elite athletes

Untrained individuals have a low BLT (reach BLT at 50-60% of VO2 max)
Elite athletes have a high BLT(reach BLT at 70-80% of VO2 max)

What is BLT?

Blood Lactate Threshold
The point at which blood lactate levels cause a decrease in physical activity

Effects of Lactic Acid

- hampers the breakdown of glucose
- decreases the ability of the muscle fibers to contract
- burning sensation felt in the muscles
- weakness and nausea may accompany

How to test BLT?

- take blood samples at increment levels of activity on a bike/treadmill
- Blood Lactate Threshold: when blood lactate increase significantly

3 energy systems

ATP-PC System (anaerobic alactic)
Glycolysis (anaerobic lactic)
Cellular respiration (aerobic)

ATP-PC system (equation)

PC + ADP = ATP + CREATINE

How does CP create ATP

- stored in the muscle
- Phosphate breaks off the CP molecule and attaches to the ADP molecule to create ATP
- CP requires 2-5 min. to replenish (need ATP to connect P and C again)
- Provides highest rate of ATP synthesis

ATP-PC system
- location
- energy source
- uses oxygen?
- ATP
- Duration
- chemical reactions
- by-products

- cytoplasm
- creatine phosphate, NOT GLUCOSE
- eithout oxygen
- 1 ATP molecule
- 10-15 seconds
- 1-2 chemical reactions
- creatine (harmful)

ATP-PC system (sports)

50-100m dash, high jump, weightlifting, tennis serve

Glycolysis (equation)

C6H12O6 + 2 ADP + 2 Pi = 2 C3H6O3 + 2 ATP + 2 H2O
(Glucose) (Lactate)

Glycolysis system
- location
- energy source
- uses oxygen?
- ATP
- Duration
- chemical reactions
- by-products

- cytoplasm
- glucose/glycogen
- without oxygen
- 2 ATP molecules/glucose molecule
- 15 seconds - 3 minutes
- 11 chemical reactions
- lactic acid + water

How does glycolysis create ATP?

Energy is transferred from glucose (glycogen) to rejoin phosphate to ADP to make ATP
Main product is pyruvate
If O2 is not available then pyruvate becomes lactic acid
If O2 is available then pyruvate enters cellular respiration

Glycolysis (sports)

400-800m races, shift in hockey

How does Cellular Respiration create ATP

Glycolysis (2 ATP)
Krebs cycle (2 ATP)
Electron transport chain (32 ATP)
Uses glucose, glycogen, fats, and protein to make ATP

Fats are the predominant source of energy in exercise lasting longer than 20 min
Proteins are used in chronic situations (i.e. starvation)

Cellular Respiration (sports)

prolonged activities: marathons, soccer games

Cellular Respiration (advantages/disadvantages)

- complete breakdown of glucose
- slow/requires large amounts of oxygen

Glycolysis (advantages/disadvantages)

- quick surge of power
- LA buildup causes pain/fatigue

ATP-PC (advantages/disadvantages)

- very quick surge of power
- short + muscles store small amounts of ATP/PC

Anaerobic System (general info)

None of its metabolic activity will involve O2
Utilizes chemicals and enzymes
Occurs in the muscle fibre
Short-lived

Aerobic System (general info)

All of its metabolic activity will involve O2
Occurs in the mitochondria
Leads to the complete breakdown of glucose

What is ATP?

- Usable form of glycogen
- Adenosine triphosphate (ATP)

ATP (general info)

ATP consists of 3 phosphates attached by high-energy bonds to adenosine and ribose
Energy is released when a trailing phosphate is broken from the ATP molecule. This results in ADP + Energy
ATP energy supplies are used up very quickly and so need to be resynthesized

Carbohydrates (general info)

Most abundant organic substances in nature
essential for human and animal life.
Most important source of energy for physical activity
most plentiful and easily metabolized

Carbohydrates (origins)

Originate from plants, such as vegetables, fruits, and grain-based foods such as bread and pasta.
Carbohydrates are formed by green plants through PHOTOSYNTHESIS
carbon dioxide + water = oxygen + glucose

What is metabolism?

the process by which energy is supplied throughout the body with energy-rich material (fats, proteins, carbohydrates) and are assimilated by the body for the purposes of energy renewal

Fats (general info)

Primary sources of energy are carbohydrates and fats
Fats contain the largest amount of stored energy
2x as much as protein and carbs

Fats (storage)

Found in the muscle and adipose tissue as fatty acids
Stored in the body as triglycerides

What is Lipolysis?

- process that breaks down triglycerides
- fatty acids are available as an energy source
- Fatty acids enter the energy system during the Krebs cycle in the aerobic system

Proteins (general info)

Protein contains as much energy as carbohydrates
No protein reserves in the body
all proteins are part of existing body tissue
unlike fats and carbohydrates

When is protein used?

- endurance activities and in chronic conditions
(when glycogen reserves are significantly diminished)
- Excessive intake of protein may put excessive strain on the liver and kidneys

Protein supplements (info)

Eating large amounts of high-protein foods/taking protein supplements does not automatically result in an increase of muscle mass or an increased ability to perform better at sports
0.36-0.45 g of protein per pound of body weight is recommended per day

Amino Acids (general info)

Protein in the body is comprised of 20 different amino acids
9 essential AA - not created by the body but must be consumed
used by the body to form various body tissues
Proteins must be broken down into amino acids to be used as an energy source
Amino acids are converted in the liver to glycogen

Where is glucose stored?

stored within skeletal muscle and liver as GLYCOGEN

Removal of lactic acid?

- 30-60 minutes of exercise recovery
- 1-2 hours of rest recovery

Cellular respiration system
- location
- energy source
- uses oxygen?
- ATP
- Duration
- chemical reactions
- by-products

- mitochondria
- glycogen, fats, proteins
- with oxygen
- 36 ATP molecules/glucose molecule
- 120 seconds +
- glycolysis, krebs, electron transport
- water + carbon dioxide

Cellular Respiration (equation)

C6H12O6 + 6 O2 + 36 ADP + 36 Pi = 6 CO2 + 36 ATP + 6 H2O