pe a level paper 1 - environmental effects

Altitude Acclimatisation

The process of the body adjusting to the decreased availability of O2. It is a slow process taking place over a period of weeks.

Barometric Pressure

The pressure exerted by the earth's atmosphere at any given point. Sometimes referred to as atmospheric pressure.

Cardiovascular Drift

Slight increase in heart rate during sustained steady-state activity which is associated with an increase in body temperature but no increase in work load.

Dehydration

Rapid loss of water in body tissues largely caused by sweating.

Humidity

The amount of water vapour in the atmospheric air.

Hyperthermia

Significantly raised core body temperature.

Thermoregulation

The process of maintaining core temerature

Hypoxia

A condition where respiring tissue is deprived of adequate O2.

Altitude Training

Training at high altitude for several weeks until acclimatisation occurs. Perfect for aerobic performers who see benefits on their return to sea level.

Negatives of altitude training

1. aerobic performance deteriorates

2. detraining or reversibility occurs

3. decreased VO2 max

4. early fatigue

5. early lactate threshold and OBLA.

Post-acclimitisation

Positive effects on the cardiovascular and respiratory systems from altitude training

4 cardiovascular adaptations from altitude training

1. increased capillary density around alveoli and muscles

2. increased release of erythropoietin (EPO)

3. increased haemoglobin content in the blood

4. increased oxygen carrying capacity of the blood.

3 respiratory adaptations from altitude training

1. increased surface area of alveoli

2. increased capacity for diffusion during external and internal respiration

3. increased strength of respiratory muscles - diaphragm, external intercostals, sternocleidomastoid, pectorialis minor, internal intercostals, rectus abdominis.

4 effects of altitude training when back at sea level

1. aerobic performance improves

2. delayed lactate threshold and OBLA

3. delayed fatigue

4. increased VO2 max

Hypothalamus

The region of the brain responsible for controlling body temperature.

Thermoreceptors

Sensory receptors that detect changes in core body temperature and send the information to the hypothalamus.

Heat Acclimatisation

The process in which the body adjusts gradually to a change in environmental temperature.

Altitude

The height in metres of a location above sea level. 2200m is considered the optimal altitude for altitude training.

3 effects of heat on the cardio-respiratory systems

1. breathing frequency (f) increases

2. increased risk of symptoms of asthma due to increased pollen count

3. decreased efficiency of the cardiovascular and respiratory systems.