exercise and immune function Flashcards
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exercise and immune
increasing physical activty reduces risk of resp illnesses
infections are shorter and less severe in people who are more active
engaging in regular moderate vigorous physical activity (MVPA) reduces risk of catching and dying from resp infections
MVPA associated with 31% lower risk of community acquired infections
moderate exercise linked to lower risk of infections
organisation- WBC
white blood cells (leukocytes) split into:
- monocytes + granulocytes - innate/non specific (natural killer cells)
- lymphocytes- adaptive/acquired/ specific immune system (including t cells and b cells)
helper T cells
helper t cells- 60% of T cells, express CD4, control and modulate development of immune response, also include regulatory T cells which switch off response
help to activate B cells and cytotoxic t cells
B cells
go on to produce antibody
plasma cells–> activated B cells–> memory B cells
plasma cells segcrete immunogloblin known as antibody when it binds to non self protein - antigen
Ig recognises molecular shapes (epitopes) on antigens expressed by infected cells
they bind to antigen on the target cell and destroy the cell
fitness
aerobic fitness in gen pop is associated with higher % of circulating naive T cells (CD8)
also associated with lower proportion of exhausted t cells in circulation - to proportion of exhausted T helper and cytotoxic cells
regular moderate intensity mixed resistane and aerobic exercise increased anti viral Tcells in older people
ability of T cells to proliferate is higher in regularly active older women
saliva levels of IgA increased after 12 week moderate aerobic exercise programme
intensive exercise
acute intensive exercise decreases T cell ability to proliferate
T cell proliferation in response to flu is lowered by intensive exercise on consecutive days
training load effects proportions of anti viral T cells numbers at rest- sig lower in intensified training
salivary iga falls during periods of intensive training and competition
peaks in infections coincide with salivary s-iga
iga is the most abundant type of antibody in the body
causes of increased infection
increases exposure to pathogens
leads to increases susceptibility to infection
causes- physiological, psychological and environmental stress, inadequeate diet and lack of sleep
nutritional supplements can be taken by athletes to reduce risk and severity of respiratory infections
probiotics
live microorganims which can provide health benefits
act to modify intestinal bacteria by increasing number of beneficial bacteria and decreasing the numbers of harmful species
help inhibit the growth and reduce harmful effects of other bacteria, antigens, toxins and carcinogens in gut
interact with gut- associated immune tissue
probiotic intake lowered resp infection experience
daily probiotic prevented usual seasonal decreases in resting salivary s-iga in athlete cohort
vitamin D
has recognised role in immunity
important role for bone health and muscle function
has direct effects on immune cell functions, most immune cells express vit D receptor
resp infections higher between nov- march as there is insufficient UV-B rays to produce vit D from our skin
low saliva siga secretion rate associated with sub optimal vit d status
vit d supplementation in 25 taekwondo athletes reduced symptom severity but had no effect on salivary iga
organisation- innate
monocytes/macrophages -
granulocytes- main neutrophils- natural killer cells
non specific
organisation- adaptive/specific
adaptive immune response- pivotal for anti viral defence
lymphocytes- T cells (thymus)- 60-75% lymphocytes, cell mediated response
B cells- bone marrow- 5-15%, humoral or fluid respons
cytotoxic t cells
cytotoxic T cells- 30-40% of T cells, express CD8, highly efficient killers of virus infected cells
cytotoxic- destroy infected cells by inserting pore forming molecules (perforins) into infected cell membrane causing it to lyse
form memory cells
