title: The effects of acute exercise on neutrophils and plasma oxidative stress.
abstract: OBJECTIVE
  To investigate the influence of intensity versus total energy expenditure on neutrophilia and blood oxidative stress to acute exercise.
  
  
  METHODS
  Nine males (18-30 yr) completed one maximal (Max) and three submaximal exercise sessions: 1) 45 min at 10% above (LT+) lactate threshold (LT), 2) 45 min at 10% below (LT-) LT, and 3) 10% below LT until caloric expenditure equaled the 10%+ trial (LT-kcal). Blood was sampled before (PRE), immediately (POST), 1 h, and 2 h after exercise to measure neutrophils, myeloperoxidase, superoxide (O(2)-), neutrophil activation (O(2)-/neutrophils), ascorbic acid, uric acid, malondialdehyde, and lipid hydroperoxides.
  
  
  RESULTS
  Intensity-dependent neutrophilia occurred POST exercise with significant increases (P <or= 0.05) after Max and LT+. A second neutrophilia wave occurred 2 h postexercise. Superoxide was elevated POST (Max) and 2 h post (Max and LT+). In contrast, O(2)-/neutrophils was increased at 2 h only (Max and LT+). These data indicate that immediately postexercise, total neutrophil number rather than activation best represents neutrophil-generated reactive species within blood. POST Max, ascorbic acid and uric acid were decreased indicating a blood oxidative stress occurred. Alternately, total energy expenditure was not related to any marker of neutrophilia or oxidative stress.
  
  
  CONCLUSIONS
  Exercise intensity plays a major role in postexercise blood oxidative stress, whereas total exercise energy expenditure does not. Further, neutrophils recruited into circulation during exercise may impose a threshold dependent oxidative stress in blood plasma after exercise.
authors.affiliation: Department of Exercise and Sport Sciences and Physiology, Center for Exercise Science University of Florida, Gainesville, FL, USA.
authors.forename: John C
authors.initials: JC
authors.lastname: Quindry
authors.forename: William L
authors.initials: WL
authors.lastname: Stone
authors.forename: Jeff
authors.initials: J
authors.lastname: King
authors.forename: Craig E
authors.initials: CE
authors.lastname: Broeder
mesh_terms: D000293:Adolescent; D000328:Adult; D004734:Energy Metabolism; D015444:Exercise / Q000502:physiology*; D006801:Humans; D015227:Lipid Peroxidation; D008297:Male; D018375:Neutrophil Activation / Q000502:physiology*; D018384:Oxidative Stress; D010101:Oxygen Consumption