86Thousand400: Energy systems and exercise

Three main energy systems: Creatine phosphate, Lactate & Aerobic

Adenosine Triphosphate is our energy rich compound which is our main energy currency

ATP releases its energy when one of its two high energy bonds is broken (by enzyme ATPase)

Creatine Phosphate and lactate system require no oxygen

Creatine Phosphate stores are replenished in one of two ways

1. Liver and Kidneys produce CP from amino acids

2. Dietary intake - meat/fish (Approx 120g of phosphocreatine in body)

It takes approx 30s - 5 mins to replenish Creatine Phosphate stores (depending on intensity and duration)

The lactate system can last between 60 - 180 seconds eg 400m/100m swim

Aerobic system dominant during low intensity activity

Lactate system results in the complete breakdown of carbohydrate. Also results in 'burning' sensation in muscles

Aerobic system involves complete breakdown of CHO & fats. By products are CO2, Water & Heat

Training adaptations through aerobic training:

Pulmonary - improved efficiency of respiratory muscles

Cardiovascular - lower resting heart rate, increased stroke volume, increased cardiac output.

Also increase in size and number of mitochondria. (More mitochondria = greater ATP production)

Also increase in aerobic enzymes which increases muscles ability to metabolise (burn) fat and CHO

Training adaptations targetted at Creatine Phosphate

system are to increase muscle mass and improve activation of muscles by the nervous system

Lactate tolerance. Increased aerobic system = increased lactate tolerance

Muscles utilise O2 therefore produce less lactic acid at given intensity

Anaerobic training improves tolerance of build up of lactic acid. This improves the body's ability to withstand the build up of lactic acid and/or the ability to remove it more quickly, which delays or prevents the accumulation of fatigue