TY - JOUR

T1 - Effects of exercise intensity, duration and recovery on in vitro neutrophil function in male athletes

AU - Robson, P J

AU - Blannin, A K

AU - Walsh, N P

AU - Castell, L M

AU - Gleeson, M

PY - 1999/2

Y1 - 1999/2

N2 - The aim of the present study was to compare the effects of exercise at 80% VO2max (resulting in fatigue within 1 h) with more prolonged exercise at a lower work rate (55% VO2max for up to 3 h) on blood neutrophil function and plasma concentrations of cortisol, glutamine and glucose. Eighteen healthy male subjects (mean+/-SD age 22.5+/-3.7 yrs, VO2max 60.1+/-6.6 ml x kg(-1) x min(-1)) cycled on an electrically braked ergometer at 80% VO2max to fatigue (37+/-19 min). On another occasion, separated by at least one week, subjects performed exercise on the same ergometer at 55% VO2max for 3 h or to fatigue, whichever was the sooner. Mean exercise time was 164+/-23 min. The order of the trials was randomised. Both exercise bouts caused significant (p<0.05) elevations of the blood leucocyte count and plasma cortisol concentration and reductions in the in vitro neutrophil degranulation response to bacterial lipopolysaccharide and oxidative burst activity. After exercise at the lower work rate for a longer duration, plasma cortisol concentration was higher, blood leucocyte and neutrophil counts were higher, blood lymphocytes, plasma glucose and indices of neutrophil function were lower than those observed at 80% VO2max. Plasma glutamine only fell significantly during recovery after the more prolonged exercise. We conclude that when exercise is very prolonged, the diminution of innate immune function is greater, or at least as great as that observed after fatiguing exercise at higher work rates. Furthermore, reductions in neutrophil function after exercise at 80% VO2max were not related to changes in the plasma glutamine concentration, although both plasma glutamine and neutrophil function were decreased at 1 and 2.5 h post-exercise in the long duration exercise trial.

AB - The aim of the present study was to compare the effects of exercise at 80% VO2max (resulting in fatigue within 1 h) with more prolonged exercise at a lower work rate (55% VO2max for up to 3 h) on blood neutrophil function and plasma concentrations of cortisol, glutamine and glucose. Eighteen healthy male subjects (mean+/-SD age 22.5+/-3.7 yrs, VO2max 60.1+/-6.6 ml x kg(-1) x min(-1)) cycled on an electrically braked ergometer at 80% VO2max to fatigue (37+/-19 min). On another occasion, separated by at least one week, subjects performed exercise on the same ergometer at 55% VO2max for 3 h or to fatigue, whichever was the sooner. Mean exercise time was 164+/-23 min. The order of the trials was randomised. Both exercise bouts caused significant (p<0.05) elevations of the blood leucocyte count and plasma cortisol concentration and reductions in the in vitro neutrophil degranulation response to bacterial lipopolysaccharide and oxidative burst activity. After exercise at the lower work rate for a longer duration, plasma cortisol concentration was higher, blood leucocyte and neutrophil counts were higher, blood lymphocytes, plasma glucose and indices of neutrophil function were lower than those observed at 80% VO2max. Plasma glutamine only fell significantly during recovery after the more prolonged exercise. We conclude that when exercise is very prolonged, the diminution of innate immune function is greater, or at least as great as that observed after fatiguing exercise at higher work rates. Furthermore, reductions in neutrophil function after exercise at 80% VO2max were not related to changes in the plasma glutamine concentration, although both plasma glutamine and neutrophil function were decreased at 1 and 2.5 h post-exercise in the long duration exercise trial.

KW - Adult

KW - Exercise

KW - Exercise Test

KW - Glutamine

KW - Humans

KW - Lactic Acid

KW - Leukocyte Count

KW - Male

KW - Neutrophils

KW - Oxygen Consumption

KW - Pancreatic Elastase

KW - Sports

KW - Clinical Trial

KW - Comparative Study

KW - Journal Article

KW - Randomized Controlled Trial

KW - Research Support, Non-U.S. Gov't

U2 - 10.1055/s-2007-971106

DO - 10.1055/s-2007-971106

M3 - Article

C2 - 10190775

VL - 20

SP - 128

EP - 135

JO - International Journal of Sports Medicine

JF - International Journal of Sports Medicine

SN - 0172-4622

IS - 2

ER -