title: The effect of vigorous running and cycling on serum COMP, lubricin, and femoral cartilage thickness: a pilot study.
abstract: OBJECTIVE
  Our aim was to investigate lubricin, cartilage oligomeric matrix protein (COMP), and femoral cartilage deformation in response to different biomechanical loading of the knee joint (running vs cycling).
  
  
  METHODS
  Serum lubricin and COMP concentrations (enzyme-linked immunosorbent assay), and femoral cartilage thickness (suprapatellar transverse ultrasonography) were determined in 11 male runners (age: 40 ± 6 years; weight: 76 ± 8 kg) and 11 male cyclists (35 ± 12 years; 75 ± 5 kg) at baseline, immediately after, and 30 min after vigorous exercise (time trial: 10-km run or 25-km cycle).
  
  
  RESULTS
  At baseline, lubricin (runners: 104.0 ± 19.8 ng/ml; cyclists: 119.1 ± 23.9 ng/ml) and COMP (runners: 804.1 ± 87.5 ng/ml; cyclists: 693.0 ± 84.7 ng/ml) did not significantly differ; however, vigorous exercise was accompanied by an increase in lubricin (cyclists: 39.4 %; p < 0.05; runners: 56.9 %; p < 0.05) and COMP (cyclists: 32.1 %; p < 0.05; runners: 14.2 %; p = 0.14) that returned toward baseline following 30 min of rest (p < 0.05). No between-group differences were observed for baseline cartilage thickness at the intercondyle notch, medial condyle, and lateral condyle, and vigorous exercise did not result in significant change for either group.
  
  
  CONCLUSIONS
  In the absence of ultrasonographic knee cartilage deformation, the response of serum lubricin and COMP following acute vigorous exercise indicates an increase in joint lubrication and cartilage metabolism, respectively, which appears largely independent of exercise modality.
authors.affiliation: School of Sport, Health and Exercise Sciences, Bangor University, Bangor, UK.
authors.forename: Harry M
authors.initials: HM
authors.lastname: Roberts
authors.affiliation: School of Sport, Health and Exercise Sciences, Bangor University, Bangor, UK.
authors.forename: Jonathan P
authors.initials: JP
authors.lastname: Moore
authors.affiliation: School of Sport, Health and Exercise Sciences, Bangor University, Bangor, UK.
authors.forename: Claire L
authors.initials: CL
authors.lastname: Griffith-McGeever
authors.affiliation: School of Sport, Health and Exercise Sciences, Bangor University, Bangor, UK.
authors.forename: Matthew B
authors.initials: MB
authors.lastname: Fortes
authors.affiliation: School of Sport, Health and Exercise Sciences, Bangor University, Bangor, UK. j.thom@unsw.edu.au.|School of Medical Sciences, University of New South Wales, Sydney, NSW, 2052, Australia. j.thom@unsw.edu.au.
authors.forename: Jeanette M
authors.initials: JM
authors.lastname: Thom
mesh_terms: D000293:Adolescent; D000328:Adult; D001642:Bicycling / Q000502:physiology*; D064236:Cartilage Oligomeric Matrix Protein / Q000097:blood*; D002358:Cartilage, Articular / Q000033:anatomy & histology / Q000502:physiology*; D005260:Female; D005269:Femur / Q000502:physiology; D006023:Glycoproteins / Q000097:blood*; D006801:Humans; D007719:Knee Joint / Q000502:physiology; D008297:Male; D008875:Middle Aged; D009929:Organ Size / Q000502:physiology; D005082:Physical Exertion / Q000502:physiology*; D010865:Pilot Projects; D012420:Running / Q000502:physiology*; D055815:Young Adult; D000099158:Proteoglycan 4
chemical_list: D064236:Cartilage Oligomeric Matrix Protein; D006023:Glycoproteins; D000099158:Proteoglycan 4; C577553:TSP5 protein, human
keywords: Cartilage oligomeric matrix protein; Joint loading; Knee; Proteoglycan-4; Ultrasound