Anaerobic Energy Systems + Anaerobic Training

First Law of Thermodynamics

Energy is neither created nor destroyed, it is transformed from one form to another.

Photosynthesis

CO2+H2O and chlorophyll + sun’s radiant energy → CHO (carbohydrate)

Substrates

Macronutrients that provide energy.

Second Law of Thermodynamics

Transformation of energy is not efficient, heat is a byproduct.

Adenosine Triphosphate (ATP)

The most common high energy, phosphate based chemical compound from which the body derives energy to do cellular work, including muscle contraction.

Adenosine

N2 Base (adenine) + 5-carbon sugar (ribose).

ATP =

Adenosine + P + P ~ P

ATP is stored in the…

Sarcoplasm of the muscle cell.

ATP is like a…

Flare in the trunk of a car, lots of stored energy waiting to be released.

Hydrolysis

The breakdown of ATP to yield energy to perform cellular work.

When an inorganic phosphate molecule (Pi) breaks off from compound…

Energy is released.

Phosphorylation

Resynthesis of ATP by adding a phosphate to ADP left over from hydrolysis.

3 Metabolic Pathways to resynthesize ATP / 3 Energy Systems

ATP/PCr, Gylcolysis, Oxidative

ATP/PCr Energy System

Immediate, phosphagen energy.

Glycolytic Energy System

Anaerobic glycolysis, lactic acid energy system.

Oxidative Energy System

Aerobic energy system.

2 Anaerobic Energy Systems

ATP/PCr + Gylcolytic energy systems) Do not require oxygen to resynthesize ATP, occurs in sarcoplasm of cell.

Anaerobic synthesis of ATP is the primary source of energy for…

Type IIA and IIX muscle fibers, for high intensity, short duration work.

1 Aerobic Energy System

Oxidative energy system. Requires oxygen to resynthesize ATP, occurs in mitochondria.

Aerobic synthesis of ATP is the primary source of energy for…

Type I muscle fibers, for low-moderate intensity, long-duration work.

ATP/PCr energy source

Phosphagens stored in sarcoplasm of muscle cell in form of phosphocreatine (PCr).

PCr

A high-energy phosphagen stored in cells, ready to do immediate work.

Once ATP is hydrolyzed…

PCr helps to rapidly remake ATP.

After hydrolysis we are left with…

ADP + the third phosphate becomes inorganic phosphate (Pi).

To resynthesize ATP…

Need to combine ADP and a phosphate molecule.

By recombining…

Leftover ADP from hydrolysis with PCr stored in cytoplasm → ATP resynthesized.

Creatine kinase (CK)

A rate-limiting enzyme that catalyzes reaction in ATP/PCr energy system.

Once PCr and/or CK is depleted…

Exhaustion of ATP/PCr energy system.

Time to replenish ATP + PCr stores

4-8 minutes depending on how much ATP and PCr were depleted.

Energy source of the Glycolytic Energy System

Glucose (a simple sugar molecule). Muscle either uses blood glucose or glycogen stored in muscle cell to resynthesize ATP.

Glucose

Single molecule of carbohydrates (CHO) after digestion + absorption of CHO.

Glycogen

Long chain of glucose molecules stored in sarcoplasm of the cell.

Time to exhaustion of glycolytic energy system during all-out work

~30-120 seconds.

Glycolysis

Breakdown of glucose molecule from the blood.

Glycogenolysis

Breakdown of glycogen already stored in the cell.

Glyconeogenesis

Making new glucose.

In Anaerobic Glycolysis + Glycogenolysis, glucose is converted to…

Pyruvate (in 10 steps).

Enzyme required for each of the 10 reactions for anaerobic glycolysis + glycogenolysis…

Rate-limiting enzyme PFK.

Anaerobic glycolysis occurs mostly in…

Type IIX and IIA fibers.

Energy sources for Oxidative (Aerobic) Energy System

Three substrates— carbohydrate, fat, protein

Substrates combines with OX to form…

ATP aerobically.

Oxidative Energy System occurs mostly in…

Type I and sometimes IIA fibers.

Number of Steps in ATP/PCR energy system

1 Step.

Number of steps in anerobic glycolysis + glycogenolysis

10 Steps.

Number of steps in oxidative energy system

Many steps, dependent on the substrate (CHO, fat, protein) catabolized.

Physical (health-related) fitness components:

Muscular strength + endurance, aerobic endurance, flexibility, body composition.

Performance-related (motor-skill) fitness components:

Speed, power, agility, coordination, balance, speed + power endurance.

ATP/PCr energy system intensity

Very high intensity (muscular strength, power, speed, agility).

Glycolytic energy system intensity

High intensity (muscular endurance, speed endurance, power endurance).

Oxidative energy system intensity

Low to moderate intensity (aerobic endurance).

General Adaptation Syndrome

Process that describes how the body responds to stress.

Specificity

Train for particular objective → particular adaptation.

Overload

Need stimulus greater than the muscle/body is used to.

Progression

As muscle adapts to new stimulus, periodically increase stimulus.

Strength-training requires…

<1.6 grams of protein per kg of body mass per day (1.6 g/kg/d) for optimal strength gains.

Neural disinhibition

Decreased sensitivity of Golgi Tendon Reflex (GTO kicks in at higher intensity, is able to recruit more type II motor units, increased ability to produce force).