Effects of prior exercise on eccentric exercise-induced neutrophilia and enzyme release.
OBJECTIVE
The purpose of this study was to determine the effects of prior exercise on changes in circulating neutrophils, neutrophil activation, and myocellular enzymes following a standardized bout of eccentric exercise.


METHODS
Twenty-four male volunteers were randomized into three groups (N = 8). Group C performed 10 sets of 10 eccentric contractions of the quadriceps muscles with both legs (100% of the concentric IRM). Group D and Group F exercised for 2 h at 56%VO2max on a cycle ergometer followed by a similar bout of eccentric contractions. Group F also received 7.5 mL x kg(-1) of a carbohydrate-electrolyte beverage every 30 min during the submaximal exercise, whereas group D received no fluid.


RESULTS
Body weight remained unchanged in groups C and F and decreased in group D by 1.56 +/- 0.34 kg. Ultrastructural Z-Band damage increased three-fold following exercise and remained elevated 3 d after exercise but was not different among groups. Circulating neutrophils were elevated more in group D compared with those in group C immediately after the exercise or rest period, and this difference persisted 3 h after the eccentric exercise. Serum lactoferrin concentrations increased 3.3-fold after exercise in all groups (P < 0.01). Creatine kinase levels (CK) rose in all subjects, with subjects in Group F and D having a significantly greater rise in CK after exercise compared with those in group C.


CONCLUSIONS
These data indicate that submaximal exercise followed by a bout of eccentric exercise results in similar amounts of myofibrillar injury with a larger neutrophil response and CK release.
Fielding
R A
RA
Department of Health Sciences, Sargent College of Health and Rehabilitation Sciences, Boston University, MA 02215, USA. fielding@bu.edu
Violan
M A
MA
Svetkey
L
L
Abad
L W
LW
Manfredi
T J
TJ
Cosmas
A
A
Bean
J
J
D000328:Adult; D001835:Body Weight; D003402:Creatine Kinase / Q000378:metabolism*; D015444:Exercise / Q000502:physiology*; D006801:Humans; D008297:Male; D009119:Muscle Contraction / Q000502:physiology; D018482:Muscle, Skeletal / Q000293:injuries; D009210:Myofibrils / Q000502:physiology* / Q000648:ultrastructure; D009504:Neutrophils / Q000502:physiology*
D003402:Creatine Kinase