title: Effects of exercise intensity on clot microstructure and mechanical properties in healthy individuals.
abstract: BACKGROUND
  Exercise is well established to lead to exercise-induced hypercoagulability, as demonstrated by kinetic coagulation markers. It remains unclear as to whether exercise-induces changes lead in clot development and increased polymerisation. Fractal dimension (df) has been shown to act as a marker of clot microstructure and mechanical properties, and may provide a more meaningful method of determining the relationship between exercise-induced hypercoagulability and potential clot development.
  
  
  METHODS
  df was measured in 24 healthy individuals prior to, after 5min of submaximal exercise, following maximal exercise, 45min of passive recovery and following 60min of recovery. Results were compared with conventional markers of coagulation, fibrinolysis and SEM images.
  
  
  RESULTS
  Significantly increased df was observed following exercise, returning to resting values following 60min of recovery. The relationship between df and mature clot microstructure was confirmed by SEM: higher df was associated with dense clots formed of smaller fibrin fibres immediately following exercise compared to at rest. Conventional markers of coagulation confirmed findings of previous studies.
  
  
  CONCLUSIONS
  This study demonstrates that df is a sensitive technique which quantifies the structure and properties of blood clots following exercise. In healthy individuals, the haemostatic balance between coagulation and fibrinolysis is maintained in equilibrium following exercise. In individuals with underlying vascular damage who participate in exercise, this equilibrium may be displaced and lead to enhanced clot formation and a prothrombotic state. df may therefore have the potential to not only quantify hypercoagulability, but may also be useful in screening these individuals.
authors.affiliation: College of Medicine, Swansea University, Swansea, UK; NISCHR Haemostasis Biomedical Research Unit, NISCHR Haeomstasis Biomedical Research Unit, Morriston Hospital, Swansea, Abertawe Bro Morgannwg University Health Board, UK.
authors.forename: N A
authors.initials: NA
authors.lastname: Davies
authors.affiliation: College of Medicine, Swansea University, Swansea, UK; NISCHR Haemostasis Biomedical Research Unit, NISCHR Haeomstasis Biomedical Research Unit, Morriston Hospital, Swansea, Abertawe Bro Morgannwg University Health Board, UK.
authors.forename: O
authors.initials: O
authors.lastname: Llwyd
authors.affiliation: Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, Wales, UK.
authors.forename: J V
authors.initials: JV
authors.lastname: Brugniaux
authors.affiliation: College of Medicine, Swansea University, Swansea, UK; NISCHR Haemostasis Biomedical Research Unit, NISCHR Haeomstasis Biomedical Research Unit, Morriston Hospital, Swansea, Abertawe Bro Morgannwg University Health Board, UK.
authors.forename: G R
authors.initials: GR
authors.lastname: Davies
authors.affiliation: Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, Wales, UK.
authors.forename: C J
authors.initials: CJ
authors.lastname: Marley
authors.affiliation: Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, Wales, UK.
authors.forename: D
authors.initials: D
authors.lastname: Hodson
authors.affiliation: College of Medicine, Swansea University, Swansea, UK; NISCHR Haemostasis Biomedical Research Unit, NISCHR Haeomstasis Biomedical Research Unit, Morriston Hospital, Swansea, Abertawe Bro Morgannwg University Health Board, UK.
authors.forename: M J
authors.initials: MJ
authors.lastname: Lawrence
authors.affiliation: College of Medicine, Swansea University, Swansea, UK; NISCHR Haemostasis Biomedical Research Unit, NISCHR Haeomstasis Biomedical Research Unit, Morriston Hospital, Swansea, Abertawe Bro Morgannwg University Health Board, UK.
authors.forename: L A
authors.initials: LA
authors.lastname: D'Silva
authors.affiliation: School of Applied Science, Cardiff Metropolitan University, Cardiff, UK.
authors.forename: R H K
authors.initials: RH
authors.lastname: Morris
authors.affiliation: College of Medicine, Swansea University, Swansea, UK.
authors.forename: K
authors.initials: K
authors.lastname: Hawkins
authors.affiliation: College of Engineering, Swansea University, Swansea, UK.
authors.forename: P R
authors.initials: PR
authors.lastname: Williams
authors.affiliation: Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, Wales, UK.
authors.forename: D M
authors.initials: DM
authors.lastname: Bailey
authors.affiliation: College of Medicine, Swansea University, Swansea, UK; NISCHR Haemostasis Biomedical Research Unit, NISCHR Haeomstasis Biomedical Research Unit, Morriston Hospital, Swansea, Abertawe Bro Morgannwg University Health Board, UK. Electronic address: phillip.evans2@wales.nhs.uk.
authors.forename: P A
authors.initials: PA
authors.lastname: Evans
mesh_terms: D000328:Adult; D001777:Blood Coagulation; D001780:Blood Coagulation Tests; D015444:Exercise; D005260:Female; D005337:Fibrin / Q000648:ultrastructure; D006339:Heart Rate; D006801:Humans; D008297:Male; D019851:Thrombophilia / Q000097:blood / Q000175:diagnosis; D055815:Young Adult
chemical_list: D005337:Fibrin
keywords: Biomarker; Clot structure; Exercise; Fractal