title: Diurnal variation, response to eccentric exercise, and association of inflammatory mediators with muscle damage variables.
abstract: This investigation determined whether inflammatory mediators 1) have diurnal variations, 2) respond to high-force eccentric exercise, and 3) associate with markers of muscle damage after high-force eccentric exercise. College-aged men and women (n = 51) completed exercise (3 x 15 maximal eccentric elbow flexor actions using 1 arm) and control conditions in random order. Blood was collected preexercise and 4, 8, 12, 24, 48, and 96 h postexercise. Additional measures included maximal isometric force and midbiceps arm circumference (to detect swelling). Serum and plasma were analyzed for soluble tumor necrosis factor receptor-1 (sTNFR1), IL-6, C-reactive protein, cortisol, and creatine kinase (CK) activity. Relative to the 7:00 AM point in the control condition, diurnal decreases were measured at 12:00 PM and 4:00 PM for IL-6 and at 12:00 PM, 4:00 PM, and 8:00 PM for sTNFR1 and cortisol. sTNFR1, IL-6, CK, swelling, and soreness were higher in the exercise compared with the control condition. The largest of the inflammatory mediator responses was measured for IL-6 8 h postexercise in the exercise (3.00 +/- 3.59 pg/ml) relative to the control condition (1.15 +/- 0.99 pg/ml). The IL-6 response (time-matched exercise--control concentration) at 8 h associated (r > 0.282) with muscle soreness at 24 and 96 h, and the cortisol response at 8 h associated (r > 0.285) with swelling at 8, 24, and 96 h. Thus soreness and swelling, but not CK and strength loss, had a low association with the inflammatory response following eccentric exercise.
authors: Montana State Univ., Dept. of Health and Human Development, P.O. Box 173360, Bozeman, MT 59717, USA. mmiles@montana.edu
authors: Mary P
authors: MP
authors: Miles
authors: Jan M
authors: JM
authors: Andring
authors: Sherri D
authors: SD
authors: Pearson
authors: Lindsay K
authors: LK
authors: Gordon
authors: Christine
authors: C
authors: Kasper
authors: Christopher M
authors: CM
authors: Depner
authors: Jessy R
authors: JR
authors: Kidd
mesh_terms: D000328:Adult; D002940:Circadian Rhythm; D052283:Creatine Kinase, MM Form / Q000097:blood; D004487:Edema / Q000097:blood / Q000503:physiopathology; D015444:Exercise; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D007249:Inflammation / Q000097:blood / Q000473:pathology / Q000503:physiopathology*; D018836:Inflammation Mediators / Q000097:blood*; D015850:Interleukin-6 / Q000097:blood; D008297:Male; D009119:Muscle Contraction; D053580:Muscle Strength; D018482:Muscle, Skeletal / Q000201:enzymology / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology*; D009135:Muscular Diseases / Q000097:blood / Q000473:pathology / Q000503:physiopathology*; D010146:Pain / Q000097:blood / Q000503:physiopathology; D010147:Pain Measurement; D047888:Receptors, Tumor Necrosis Factor, Type I / Q000097:blood; D013997:Time Factors
chemical_list: C508600:IL6 protein, human; D018836:Inflammation Mediators; D015850:Interleukin-6; D047888:Receptors, Tumor Necrosis Factor, Type I; D052283:Creatine Kinase, MM Form; D006854:Hydrocortisone