ANAEROBIC AND AEROBIC ENERGY SYSTEMSChapter 7

Anatomy and Physiology for Coaches

Muscles Fibers need energy to sustain contraction

2 main sources of stored energy ATP (Adenosine Triphosphate) PCr (Phosphocreatine)

When stored energy runs low, the body must produce more ATP Carbohydrate (glycogen) stored in muscle and liver

Anaerobic glycolosis By-product is lactic acid

Carbohydrate in blood Aerobic system

ANAEROBIC SYSTEM

Non – oxidative (with out oxygen) Brief but intense Byproduct is Lactic Acid Important at the onset of exercise Important for events of short duration Low efficiency 1 glucose = 3ATP

LACTIC ACID

By product of Anaerobic metabolism Change the acid-base balance in the muscle

cell Reducing energy production by the aerobic

system Causing burning sensation in muscles,

nausea physical and mental fatigue Training reduces production of Lactic acid

and improved the body’s ability to remove it from the system.

ANAEROBIC POWER

Maximal all out effort for several seconds ATP-PCr energy system

Nervous system sends a message to muscle cell ATP is split to ADP to release energy PCr restores ADP to ATP, thus repeating the

cycle. Anaerobic glycolysis

Break-down of glycogen with out oxygen. 3 ATP / 1 glucose Produces lactic aid

AEROBIC

Uses oxygen to produce energy Abundant energy stores

Carbohydrates 4 Kcal / gram Fat is abundant and rich energy source 9 Kcal / gram

More efficient than anaerobic 1 glucose = 36 ATP

Occurs in Mitochondria of the cell.

Glucose + O2 = CO2 + H2O + energy

* Protein is essential to build, maintain and repair issue, but is not a preferred energy source.

AEROBIC CAPACITY

The ability of the aerobic system to take in, transport and utilize oxygen.

a product of the respiratory, cardiovascular and muscular systems.

Measured in L/min Higher measures indicate excellence in non-

weight bearing sports.

AEROBIC POWER

Aerobic capacity in relation to body weight Measured in ml/kg/min One’s ability to use oxygen per unit of body

weight Predictor of performance in weight bearing

activities

ANAEROBIC THRESHOLD

Lactate threshold Transition zone that involves increase

dependence on the anaerobic system. Upper limit of body’s ability to clear lactic

acid. Lactate threshold 1

Easy training zone Uses primary slow oxidative muscle fibers

Lactate threshold 2 fatigue occurs rapidly Performance threshold

Both thresholds can be increased with training.

SPORT SPECIFIC TRAINING

It is important to understand the demands of your sport

Train to specifically meet the demands of your sport.

Understanding specific energy demands helps to focus training for success.

ENERGY TRAINING

Anaerobic For sports needing max effort or force production Sprinters and heavy lifters Uses stored ATP, CPr and Non-oxidative breakdown Events lasting up to 2 mins. Subtle changes seen with training

Aerobic Training effects are clear Increase in mitochondria, increase enzyme activity,

greater oxygen uptake, increase in fibers to produce ATP.

Improvements in Cardiovascular and Respiratory systems.

Improved ability to burn fat.

OTHER TRAINING EFFECTS

Blood volume / stroke volume Amount of blood pumped per beat Aerobic training can increase blood volume Increase blood returned to the heart and pumped

to the working muscle Slower resting and exercise heart rates

Cardiac Output Volume of blood pumped per minute Cardiac output = heart rate x stroke volume

Respiration Becomes more efficient with training Greater tidal volume less frequency is needed to

meet the demands. Ventilation = tidal volume x frequency