Illness in athletes and how to avoid them

Question 1

Explain the relevance of the J shaped model (Neiman 1994)

Answer 1

High intensity exercise is associated with an above average number of colds per year

Question 2

What was the finding of Neiman et al 1990 study into illness in marathon runners

Answer 2

1 week after running the LA marathon, runners were 6 times more likely to experience a control than controls

positive correlation between OR of having URTI and km/week of training

Question 3

What were the findings of Bury et al 1998 in a study into illness in footballers

Answer 3

77% of illness was during the cold season which is also when there is fixture congestion

players had more coughs and colds which also lasted longer vs playing staff

Question 4

Outline the reasons why athletes have an increased exposure to pathogens

Answer 4

Increased rate of lung ventilation

Breath through mouth so bypass protective processes in nose

skin abrasions in certain sports

foreign travel so newly encountered pathogens

long haul flights with re-circulated air

crowds with new pathogens

team showers so pathogens in warm enviroment

Question 5

Why do city marathon runners have an increased risk of becoming ill vs other athletes

Answer 5

increased pollution in the air

pollutants decrease the immune response in the lungs

Question 6

Give reasons why athletes may be immune supressed

Answer 6

Physiological and psychological stress
enviromental stress e.g temperature
Inadequate diet (too much protein not enough carbs)
lack of sleep

Question 7

What are the acute effects of exercise on the immune system and what is the implication of this

Answer 7

Elevated leukocyte count, but supressed function

elevated count means less are available later if needed

Need to allow adequate recovery time so leukocyte function can be restored, otherwise chronically supressed

Question 8

What are the chronic effects of exercise on the immune system

Answer 8

Lower resting leukocyte count
decreased leukocyte function
supressed antibody function (IgA)

Question 9

What is the importance of salivary IgA in relation to URTI

Answer 9

Low levels or poor salivary flow rates are associated with increased incidence of URTI

Question 10

What were the findings of Gleeson 1999 in relation to salivary IgA

Answer 10

Inverse association between resting amount of salivary IgA and number of infections

Results demonstrated a substantial contribution for one aspect of the immune system alone

Question 11

What were the findings of Engles and Fahlman 2005 when comparing American college Footballers and non-playing controls

Answer 11

controls = relativly constant IgA levels

Footballers = fall in IgA in autumn and spring which is also when training hardest and had most matches

Dip in IgA coincided with peak of infections with >50% having infection at this time

Question 12

Explain the methods of Neville et al 2008

Answer 12

Found each athletes average natural level of IgA

then took IgA sample each week to find % of average IgA

documented when athlete had an infection

Question 13

What were the findings of Neville et al 2008

Answer 13

low IgA = more colds
before a cold, levels of IgA were falling

40% fall in IgA = 50% chance of cold

Question 14

How can the findings of Neville et al 2008 be used

Answer 14

Coaches can see when athlete IgA is falling and then implment stratergies or alter training load to decrease chance of infection developing

Question 15

What is the limitation of trying to reduce transmission of pathogens as a way of decreasing infections

Answer 15

No always the easiest to implement in day to day work during sport

Question 16

Name ways by which an athlete can maintain an healthy immune system

Answer 16

Allow sufficient recovery time

avoid micronutrient deficiency

Ingest carbohydrates during exercise

Daily probiotic and Vit D supplement

Question 17

What ways can an athlete be better managed to decrease their chances of infection

Answer 17

Monitor mood 
monitor fatigue levels 
avoid prolonged training sessions 
allow recovery days 
vaccination

Question 18

what was the link between salivary IgA and fatigue, described by Neville et al 2008, and how can this be used by coaches

Answer 18

As level of perceived fatigue increases there was a significant decrease in salivary IgA

Can monitor fatigue levels as an indicator of likelyhood of illness rather than IgA bc this is easier to do

Question 19

Bishop et al 2005

Answer 19

Participants did shuttle runs over 2 days and were then exposed to flu virus

One group consumed carb drinks during shuttle runs, other didn’t

carb consumers had restored immune function at start of day 2 whereas non consumers was decreased

immune function was anti-viral cells

Question 20

Bishop et al 2009

Answer 20

2 hour run at 60%V02max

carb vs placebo drink

measured CD4 migration to infected lung cells

carb group migration rates fell to 80%
placebo group fell to 40%

Question 21

Gleeson and Bishop 2011 (probiotic)

Answer 21

Daily probiotic vs placebo drink for 16 weeks during winter training for endurance athletes

proportion of athletes with cold decreased in probiotic group

potentially due to preventing season fall in salivary IgA

Question 22

Gleeson and Bishop 2013 (Vit D)

Answer 22

catagorised people as optimal, adequate, inadequate or deficient in Vit D

as levels decreased, incidence and severity of infections increased

salivary IgA also higher in optimal group so potential link there

Question 23

Prather et al 2105 (sleep)

Answer 23

Innoculated people and then monitored amount of sleep they got

those sleeping for less than 5 hours or for 5-6 hours were 4x more likely to get a cold than those sleeping for 7 hours

Question 24

Cox et al 2008 (non-infectious)

Answer 24

40% of athletes having cold symptoms actually had an allergy
once known, very easy to treat.