Unit 13 - Exercise and immunity

Immunity

The immune system protects the body from infectious disease. It is involved in tissue repair and protection against potential pathogen

Innate systems

it is present before any exposure to pathogens and is effective from the day you were born

Adaptative system

develops only after exposure to microbes and toxins

What innate mechanisms does the body use in response to infection ?

Physical, Chemical, Leucocytes

What adaptative mechanisms does the body use in response to infection ?

• Inflammation

– Clotting

– Lymphocyte and antibody production

How do leucocytes respond to injury ?

• flood to injury site to kill bacteria/foreign debris

• clean up damage cells

Why do injury sites inflame to prevent injury ?

• increases blood flow to deliver leucocytes/ platelets to the injury

• increased blood flow to graze will lead to bleeding which helps to remove debris and toxins

How does clotting occur in response to injury ?

• platelets rapidly form a clot to reduce bleeding

• clots provide a scaffold for cells involved involved in tissue regeneration

What do lymphocytes do ?

Attack viral infections that may enter a graze

What do antibodies do ?

Fight infections that enter the broken skin barrier

Effects of intense and long-term training on the immune system:

- Decrease in innate and adaptive immune function

- Increased levels of cortisol and adrenaline

- Low levels of leukocytes

- Increased tissue damage and inflammation

Discuss the relationship between exercise and susceptibility to infection

Athletes are more susceptible to infections than their sedentary peers because they have:

- lower leukocyte numbers caused by the stress of the exercise

- inflammation caused by muscle damage

- greater exposure to airborne bacteria and viruses because of an increased rate in the depth of breathing

Immune system of sedentry individuals:

• don’t have good circulation (prevents the body from fighting infections)

• prevents free movement of cells and substances of the immune system through the body

Immune system of moderately active individuals

the best for your immune system

• better circulation, stronger heart ⟶ healthier blood vessels

• boosts every system in the body

• increases leukocytosis (production of leukocytes), so your body has more antibodies

Immune system of elite athletes

• lower leukocytes numbers

• inflammation of muscles which prevents blood flow and adds additional stress

• deeper breathing ⟶ more likely to inhale bacteria and viruses

• sustained increase in levels of adrenaline which suppresses the immune system and increases stress hormones (cortisol)

How to minimise risk of infection amongst athletes ?

• incorporating sufficient recovery time between training days

• avoiding close contact with people that have infections

• maintaining good oral hygiene

• maintaining your body hydrated

• ensuring water is pathogen-free - maintaining good personal hygiene ex. washing hands, avoiding hand-to-mouth contact - maintaining a suitable and varied diet - ensuring you get sufficient sleep