title: Rest-interval length affects leukocyte levels during heavy resistance exercise.
abstract: We sought to determine the effect of varying rest intervals on leukocyte levels during heavy resistance exercise. Nine college men completed 2 exercise bouts of 10 sets of 10 repetitions at 65% 1 repetition maximum (1RM) leg press with 1- (1MIN) or 3-minute (3MIN) rest intervals, respectively. Blood collected at rest (PRE), immediately postexercise (POST), and 1.5 hours postexercise (1.5H) was analyzed for leukocyte levels. Data were analyzed using a 2 x 3 repeated measures analysis of variance. A greater PRE-POST lymphocytosis (+83% vs. +16%, p = 0.002) and monocytosis (+47% vs. +15%, p = 0.005) was observed following 1MIN vs. 3MIN. Serum creatine kinase (CK) activity was increased to a greater extent 24 h postexercise following the 1-minute rest protocol (p = 0.022). CK was correlated (r = 0.611) to the PRE-POST lymphocytosis. We conclude that short rest intervals increase the extent of postexercise lymphocytosis and monocytosis, when total work is kept constant.
authors.affiliation: Human Performance Laboratory, Truman State University, Kirksville, Missouri 63501, USA.
authors.forename: David L
authors.initials: DL
authors.lastname: Mayhew
authors.forename: John P
authors.initials: JP
authors.lastname: Thyfault
authors.forename: Alexander J
authors.initials: AJ
authors.lastname: Koch
mesh_terms: D000328:Adult; D003402:Creatine Kinase / Q000097:blood; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D007866:Leg; D007958:Leukocyte Count; D007962:Leukocytes / Q000378:metabolism*; D008218:Lymphocytosis / Q000378:metabolism*; D008297:Male; D012146:Rest / Q000502:physiology*; D013997:Time Factors; D014891:Weight Lifting / Q000502:physiology*
chemical_list: D003402:Creatine Kinase; D006854:Hydrocortisone