Physiology L3

Aim The aim of this session is to identify the respiratory adaptations to exercise.

How the Respiratory system works: respiratory system and how it works

Respiratory System = Function of the respiratory system Taking O2 to the working muscles Helping remove waste = Function of the respiratory system

Respiratory ADAPTATIONS Endurance training reduces the resting respiratory rate and the breathing rate during sub-maximal exercise Endurance training also provides a small increase in lung volumes: Vital capacity (the greatest volume of air that can be expelled from the lungs after taking the deepest possible breath) increases (slightly) Tidal Volume (The volume of air inhaled and exhaled at each breath) increases (slightly) Strength of the respiratory muscles is largely responsible for this as it aids lung inflation.

Respiratory ADAPTATIONS Endurance training also increases the capillarisation around the alveoli, this helps to increase the rate of gas exchange in the lungs and therefore, increase the amount of oxygen entering the blood and the amount of carbon dioxide leaving the blood

The neuromuscular system

Neuromuscular ADAPTATIONS Endurance training results in an: Increase in the muscular stores of muscle glycogen Increased of delivery of O2 to the working muscles, through, an increase in the concentration of myoglobin and increased capillary density through the muscle

Neuromuscular ADAPTATIONS How does the body deal with the increase in blood to the working muscles? By the skeletal muscles ability to consume oxygen…..how?

Neuromuscular ADAPTATIONS By increase in the number and size of mitochondria, therefore the increased activity of the enzymes involved in aerobic process’s that take place in the mitochondria As a result of the increase and size in mitochondria there is a greater use and breakdown of fat and glycogen as a fuel.

Neuromuscular ADAPTATIONS Slow twitch fibres can enlarge up to 22 % This gives the greater potential for aerobic respiration Hypertrophy of slow twitch fibres means that there is a corresponding increase in the stores of glycogen and triglycerides. This ensures a continuous supply of energy, enabling endurance capability

Neuromuscular ADAPTATIONS All of the following adaptations result in an increased VO² Max

Neuromuscular ADAPTATIONS Hypertrophy of the fast twitch fibres is a result of high intensity training. There are increased levels of ATP and PC in the muscle and an increase capacity to generate ATP by the PC energy system This is partly due to the increased activity of the enzymes which break down PC

Neuromuscular ADAPTATIONS ATP production by anaerobic glycolysis is increased as a result of enhanced activity of the glycolytic enzymes. There is also an increased ability to break down glycogen in the absence of oxygen.

Neuromuscular ADAPTATIONS As lactic acid accumulates, it decreases the Ph levels of the blood, making it more acidic. This increase level of hydrogen ions will eventually prevent the glycolitic enzyme functioning. However anaerobic training increases the buffering capacity of the body and enables it to work for longer in periods of high acidity.

Aim The aim of this session is to identify the respiratory adaptations to exercise.