exercise effects on systemic immunity

8/12/2019 Exercise Effects on Systemic Immunity

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Exercise effects on systemic immunity

DAVID C NIEMAN

Department of Health and Exercise Science,Appalachian State University, Boone,

North Carolina, USA

Review article24/01/2014

DR. ANWAR HASAN SIDDIQUI, senior resident,

dep't of physiology,jnmc, amu, aligarh

Immunology and Cell Biology (2010) 78, 496

501


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Introduction

Individuals undertaking a high-intensity, prolonged boutof exercise experience increased susceptibility todeveloping symptoms of upper respiratory tract illness(URTI) [1]

Epidemiological and experimental studies show that,

during the incubation period of an infection, depending onthe pathogen, exercise may worsen the disease outcome [2]

The mechanism of this apparent susceptibility to illness isnot yet understood; however, there is evidence that some

aspects of in vitro cellular function may be compromisedafter acute exercise.


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Introduction continued..

Publications on the topic of exercise immunology dates tomid 19th century.

Not until the mid-1980s,that a significant number ofinvestigators worldwide devoted their resources to thisarea of research endeavour.

From 1900 to 2009, just under 1200 papers on exerciseimmunology were published, with 78% of these appearingin the late1990s.

In the present article, emphasis will be placed onreviewing literature published since 1990 on the acute andchronic effects of prolonged and intensive exercise onsystemic immunity


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Effect of exercise on immunity

Many components of the immune system exhibit change afterprolonged, heavy exertion.[4]

High neutrophil and low lymphocyte blood counts inducedby high plasma cortisol Prolonged, high intensity endurance exercise leading to the

greatest degree of cell trafficking (an increase in

granulocyte and monocyte counts, a decrease inlymphocytes and an increase in the neutrophil/lymphocyteratio; Fig. 2 [5-12]


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Effect of exercise on immunity continued..

Following prolonged running at high intensity, theconcentration of serum cortisol is significantly elevatedabove control levels for several hours and this has beenrelated to many of the cell trafficking changes experiencedduring recovery.[4]

Figure 2

The neutrophil/lymphocyte

ratio increased in 10

triathletes following two

separate sessions of 2.5 h

of running ( )and cycling

(+) at approximately 75%

maximal aerobic power(VO2max).


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Increase in blood granulocyte and monocyte phagocytosis,but a decrease in nasal neutrophil phagocytosis Prolonged, high-intensity running, substances released

from injured muscle cells initiate an inflammatoryresponse.[13]

Monocytes and neutrophils invade the inflamed area andphagocytose debris.

Phagocyte specimens collected from the peripheral bloodreact differently than those taken from the respiratory

tract. Using nasal lavage samples, Mns et al. have shown that

the capacity of phagocytes to ingest Escherichia coli issignificantly suppressed in athletes compared with controls

for more than 3 days after running a 20 km road race.[14]


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Decrease in nasal and salivary IgA concentration Immunoglobulin A concentration in nasal secretions is

decreased by nearly 70% for at least 18 h after racing 31km.[15]

Following strenuous prolonged exercise, salivary secretion

rates fall, decreasing the level of IgA-mediated immuneprotection at the mucosal surface.[16]Decrease in nasal mucociliary clearance. Nasal mucociliary transit time is significantly prolonged

after a marathon race for several days and is caused in partby abnormally functioning ciliated cells.[17] Host protection in the upper airway passages is suppressed

for a prolonged time after endurance running races.


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Decrease in granulocyte and macrophage oxidative burstactivity killing activity) Following sustained, heavy exertion, granulocytes have a

reduced oxidative burst capacity.[5] The decrease in granulocyte oxidative burst may represent

a reduced killing capacity by blood neutrophils (on a percell basis) due to stress and overloading.

It has been suggested that this exercise-induced neutrophilstimulation would also result in an increased release ofneutrophil-derived ROS, such as superoxide(O2),hydrogen peroxide (H2O2), hydroxyl radicals (OH), andhypochloric acid (HOCL), into the circulation.


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Previous research has shown that phagocyte-derived ROS

are cytotoxic to neutrophils and can lead to auto-oxidationand impaired function of these cells

Decrease in NK cell cytotoxic activity Following intensive and prolonged endurance exercise,

NKCA is decreased 4060% for at least 6 h (Fig. 3).[17,18]

Cortisol induced redistribution of blood NK lymphocytes

from the blood compartment to other tissues.


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The decrease in NKCA closely parallels the drop in blood

NK cell concentration, implying that each NK cell retainsnormal function.

Figure 3

Natural killer cell activity response

to 2.5 h of intensive running in 62marathoners. *P < 0.05.


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Decrease in mitogen-induced lymphocyte proliferation Whole blood Con A-induced lymphocyte proliferation falls

3040% for more than 3 h following 2.5 h of intensiverunning.[8]

Others have reported an even greater decrease after

endurance race events.[19]

The decrease in T-cell function parallels the drop in bloodT-cell concentration.

Decrease in the delayed-type hypersensitivity skin Response The delayed-type hypersensitivity (DTH) reaction was

suppressed 60% in triathletes 2 days after competing in ahalf iron man triathlon (mean time 6.5 h).[20]

Heavy exertion blunt macrophage expression of MHC II,

negatively affecting the process of antigen presentation toT lymphocytes.


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Increase in plasma concentrations of pro- and anti-inflammatory cytokines Exercise bouts cause a sequential release of the pro-

inflammatory cytokines TNF-, IL-1and IL-6, followedvery closely by anti-inflammatory cytokines, such as IL-10and IL-1 receptor antagonist (IL-1ra).[21]

TNF-and IL-1stimulate the production of IL-6, whichinduces the acute phase response and the production of IL-1ra.

Recent work using muscle biopsies and urine samples hasshown more clearly the intimate link between all of thesecytokines.[13,22]


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Endurance exercise associated with muscle soreness

induces a greater inflammatory cytokine response thanmodes, such as cycling or rowing, that are more concentricin nature.[23]


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Summary and clinical implications

Data suggest that the immune system is suppressed and

stressed, albeit transiently, following prolonged enduranceexercise.

open window of altered immunity (which may lastbetween 3 and 72 h, depending on the immune measure)viruses and bacteria may gain a foothold, increasing therisk of subclinical and clinical infection.

Data suggest that T- and B-cell function is not consistentlyaltered by athletic endeavour, except in older adults.

This interpretation is bolstered by the finding that theantibody response to vaccination is normal in enduranceathletes.[26]


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The immune changes after heavy exertion differ markedlyfrom those following moderate exercise.

After brisk walking or sports play and drills, blood cortisoland cytokine levels remain close to pre-exercise levels,

perturbation of immune cell counts and function is mildand overall immunosurveillance is enhanced.[27,28]


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To counter exercise-induced alterations in

immunosurveillance and host protection againstpathogens, the endurance athlete should consider theseguidelines:[29]

1. Keep other life stresses to a minimum

2. Eat a well-balanced diet to keep vitamin and mineral pools in the

body at optimal levels.3. Avoid overtraining and chronic fatigue.

4. Obtain adequate sleep on a regular schedule

5. Avoid rapid weight loss (linked to adverse immune changes).

6. Avoid putting the hands to the eyes and nose7. Before important race events, avoid sick people and large crowds

when possible.

8. For athletes competing during the winter months, influenza

vaccination is recommended.


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Various immunomodulator drugs and nutritionalsupplements have received much attention, but the datathus far do not support their use as countermeasures toexercise-induced alterations in immunity[30,31].

Carbohydrate supplementation before, during and after

intensive endurance exercise lasting longer than 90 min isrecommended.[32]

Carbohydrate beverage ingestion associated with higherplasma glucose levels, an attenuated cortisol and growth

hormone response, fewer perturbations in blood immunecell counts and a diminished pro- and anti-inflammatorycytokine response


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and thats all..Thanks!!!!!!!!!!!!!!!!!!!!!

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(O bird of the divine regions, death is better than that bread )

(the bread which may hinder you from soaring to heavenly heights)

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exercise effects on systemic immunity

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