how to minimize infection risk in athletes.ppt to minimize infectio… · how to minimize infection...

1

2015 SCSEPF Conference

SPORTING CAMPUS

Prof Dr Tzai-Li LiNational Taiwan Sport University

[email protected]

How to minimize infection

risk in athletes?

2 Outline

Do elite athletes have a better immunity?

Brief introduction to the immune system

Exercise and the risk of infection?

How does heavy exercise affect immunity?

How to prevent infection?

2

3 Elite athletes with better immunity?

4 New Asian Queen of ultra-marathon

3

5 What’s happened?

6 Outline






4

7 Normal circulation

8 Inflammation

5

9 Acute inflammation

10 Mechanisms against infections

6

11 White blood cells

12 Immunity

7

13 Cellular immunity

14 Humoral immunity

8

15 The Th1/Th2 cytokine balance

16 Outline






9

17 Are athletes susceptible to infection?

Respiratory infections seemed to progress toward pneumonia after intense exercise and competitive sport (Cowles, 1918).

Some athletes experience high rates of certain illness, such as infectious

Mononucleosis (Foster et al. 1982)

Upper respiratory tract infection (URTI; e.g. common cold, sore

throat, middle ear infection) (Douglas and Hason 1978).

18 Is URTI popularly happened in athletes?

Up to 47% during the two weeks after a 56-km ultramarathon (Peter and Bateman 1983)

40% of marathon runners in the two months before and 12% of runners in the week after a marathon(Nieman et al 1990)

68% of runners after a 90-km ultramarathon (Peters et al. 1993)

50% of runners in the week after a marathon (Castell et al. 1996)

40% of elite swimmers during four weeks of intensified training (Mackinnon and Hopper 1996).

10

19 Athletes & better immunity? _ 1

Runners reporting URTI symptoms

2.2

12.9

0

3

6

9

12

15

Control Runners

%

Percentage of runners reporting episodes of upper respiratory tract infection (URTI) during the week after the 1987 Los Angeles Marathon (Nieman et al. 1990)

20 Athletes & better immunity? _ 2

Training load & relative risk of URTI

1

1.4 1.35 1.45 1.45

2

0.0

0.5

1.0

1.5

2.0

2.5

<32 32-47 48-63 64-79 80-96 >96

k m/week in 2 months pr ior to marathon

Rat

e ra

tio f

or U

RT

I

Training load (running disstance per week) and relative risk of upper respiratory tract infection (URTI) in the two months prior to the 1987 Los Angeles Marathon (Nieman et al. 1990)

11

21 Regular moderate Ex & URTI? _ 1

Observational study

26

11

3 2

1915

13

2

0

5

10

15

20

25

30

0 1 2 3

No. of colds repor ted over 12 months

Num

ber

Exercisers (n=53)

Stretchers (n=62)

Exerciser and stretchers reporting either 0, 1, 2 or 3 episodes of cold infection over the 12-month observation period (Chubak et al. 2006)


Observational study

0

2

4

6

8

10

Low Medium High

Day

s w

ith U

RS

Physical fitness

Exercise frequency

Total number of days with upper respiratory symptoms (URS) over the 12-week observation period across physical fitness and exercise frequency tertile (Nieman et al. 2011)

* * * *

12


Moderate exercise training and URTI

0

3

6

9

12

Exerc ise group control group

No.

of

days

with

UR

TI

sym

ptom

s

The number of days with symptoms of URTI in a group of mildly obese, young women randomly assigned to either 15 weeks on moderate exercise training or no exercise. The exercise group participated in brisk walking training for 45 min, 5 days a week at 60% HRR. (Nieman et al. 1990)

*


Regular PA and URTI risk

0.0

0.20.4

0.60.8

1.0

Q1 Q2 Q3 Q4

Activi ty leve l (MET-h/day)

UR

TI r

ate

ratio

Relative risk of upper respiratory tract infection (URTI) across habitual physical activity quartiles (Matthews et al. 2002)

Men <3.93 3.94-7.15 7.16-11.95 ≧11.96Women <2.38 2.39-4.09 4.10-6.24 ≧6.25

13


EX and immune responses

0

5

10

15

20

25

Tr iathletescompeted

Tr iathletesunc ompeted

RegulareExerc isers

Cum

ulat

ive

skin

tes

t sc

ore

The cumulative skin test score in a group of triathletes following a triathlon race, and, a group of triathletes who did not compete in the race and a group of moderately trainined individuals (Bruunsgaard et al. 1997)

*

26 J-shaped model _ EX & URTI risk

Nieman, D. C. (1994). International Journal of Sports Medicine, 15: S131-S141.

Below average

Average

Above average

Sedentary Moderate Very high

Amount of exercise

Risk of U

RT

I

14

27 S-shaped model _ PA/EX load & URTI

Malm, C. (2006). Scandinavian Journal of Medicine and Science in Sports, 16: 4-6

Sedentary Moderate High Elite

Above average

Average

Below average

Risk of U

RT

I

Activity level/exercise load

28 Outline






15

29

Prolonged (> 90 minutes) hard bouts of exercise may depress immune function

Blood glucose Muscle glycogen

Interleukin-6 Stress hormones

Free radicals

Depression of immune cell

functions

Factors contribute to incidence _ 1

Increased risk of infection

30

Factors contributing to increased susceptibility to infection in athletes

Increased exposure to pathogens

Physiological stressPsychological stressEnvironmental stressLack of sleepInappropriate Diet

ImmunodepressionIncreased susceptibility to infection

Lung ventilation Skin abrasions Foreign travel Crowds

Factors contribute to incidence _ 2

16

31 Open window hypothesis

Moderate exercise

Intense prolonged exercise

Risk of URTI decreased

Open window

Risk of URTI increased

Pedersen, B. K. (1999). In Psychoneuroimmunology: An interdisciolinary introduction. pp.341-358. New York: Kluwer Academic/Plenum Publishers.

Exercise

Heavy Exercise

Open window

EX stop Recovery

32 How long is the window opened? _ 1

Li, T. L. & Cheng, P. Y. (2007). European Journal of Applied Physiology,

101: 539-546

17



101: 539-546



101: 539-546

18

35 Outline






36 Does acute illness affect performance?

In athletes, decrements in performance have been associated with

Subclinical viral infection and prolonged recovery after viral

infection (Maffulli et al. 1993)

Aerobic exercise capacity during prolonged submaximal work(Danial et al, 1985)

Muscular strength (Danial et al, 1985; Friman et al. 1977).

Protein degradation and impairments of protein synthesis or energy metabolism during illness may limit exercise capacity as well as long-term adaptations to exercise training (Friman and Ilback 1992).

19

37 Are there practical considerations?

Illness needs time to recover.

Impaired strength and exercise capacity during viral infection may lead to musculoskeletal injury in athletes who attempt to continue training at high intensity during illness (Simon 1987).

Viral illness with systemic involvement (e.g. fatigue, fever, muscle aches, enlarged lymph nodes) requires one month for complete recovery before resumption to intense training (Roberts 1986).

Above the neck rule (Budgett 1990).

Symptoms above the neck: continue EX and reduce workload

Symptoms below the neck: stop EX

38 How to prevent infection? _ 1

Awarenessof vulnerability

Avoid gettinga dry mouth

Never sharedrink bottles

Good personalhygiene

Avoidsick people

Minimiseinfectious

agents

20


6%CHO drinks2.5ml/kg/20min

Balanced dietAdequate

sleep> 7 h

Monitor moodfatigue & soreness

Avoid training> 2 h

Minimizeimmuno-

suppression


Isolate infectedteam member

Decreasetraining volume

Above the neckprinciple

Increaseseverityduration

EX toleranceis reduced

Training& infection

21

41 Jackson score URTI questionnaire _ 1

How to fill in URTI questionnaire

Do you think that you are suffering from a common cold or flu today?

Fill in the circle if your answer is YES ○ If yes, please complete all the questions below:

Please indicate your response by filling in one circle for each of the following symptoms:

How to interpret

No symptom=0, mild symptom=1, moderate symptom=2, severe symptom=3

First criterion: any consecutive two-day total symptom score > 14.

Second criterion: fill the first circle ≧ 3 consecutive days.

42 Jackson score URTI questionnaire _ 2

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2015 SCSEPF Conference

SPORTING CAMPUS

Prof Dr Tzai-Li LiNational Taiwan Sport University

[email protected]

感謝聆聽

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how to minimize infection risk in athletes.ppt to minimize infectio… · how to minimize infection...

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