title: Sex differences in cardiac function after prolonged strenuous exercise.
abstract: OBJECTIVE
  To evaluate sex differences in left ventricular (LV) function after an ultramarathon, and the association of vascular and training indices with the magnitude of exercise-induced cardiac fatigue.
  
  
  METHODS
  Descriptive field study.
  
  
  METHODS
  Fat Dog 100 Ultramarathon Trail Race, Canada.
  
  
  METHODS
  Thirty-four (13 women) recreational runners (aged 28-56 years).
  
  
  METHODS
  A 100-km or 160-km mountain marathon.
  
  
  METHODS
  Baseline baroreceptor sensitivity, heart rate variability, and arterial compliance; Pre-exercise and postexercise echocardiographic evaluations of LV dimensions, volumes, Doppler flow velocities, tissue velocities, strain, and strain rate.
  
  
  RESULTS
  Finishers represented 17 men (44.8 ± 6.6 years) and 8 women (45.9 ± 10.2 years; P = 0.758). After ultraendurance exercise, significant reductions (P < 0.05) in fractional shortening (men: 40.9 ± 6.9 to 34.1 ± 7.6%; women: 42.5 ± 6.5 to 34.6 ± 7.9%) diastolic filling (E/A, men: 1.28 ± 0.68 to 1.26 ± 0.33; women: 1.55 ± 0.51 to 1.30 ± 0.27), septal and lateral tissue velocities (E'), and longitudinal strain (men: -21.02 ± 1.98 to -18.44 ± 0.34; women: -20.28 ± 1.90 to -18.44 ± 2.34) were observed. Sex differences were found for baseline cardiac structure and global function, peak late transmitral flow velocity, and estimates of LV filling pressures (P < 0.05). Regression analysis found that higher baseline arterial compliance was associated with lower reductions in cardiac function postexercise, to which sex was a significant factor for E' of the lateral wall. Faster race pace and greater lifetime ultramarathons were associated with lower reductions in LV longitudinal strain (P < 0.05).
  
  
  CONCLUSIONS
  Cardiac responses after an ultramarathon were similar between men and women. Greater evidence of exercise-induced cardiac fatigue was found to be associated with lower baseline arterial compliance and training status/experience.
  
  
  CONCLUSIONS
  These findings suggest that vascular health is an important contributor to the degree of cardiovascular strain incurred as the result of an acute bout of prolonged strenuous exercise.
authors.affiliation: *Cardiovascular Physiology and Rehabilitation Laboratory, University of British Columbia, Vancouver, Canada; †Experimental Medicine Program, Faculty of Medicine, University of British Columbia, Vancouver, Canada; ‡Applied Human Sciences, University of Prince Edward Island, Charlottetown, Canada; §Environmental Physiology Laboratory, School of Kinesiology, University of British Columbia, Vancouver, Canada; and ¶Division of Sports Medicine, University of British Columbia, Vancouver, Canada.
authors.forename: Anita T
authors.initials: AT
authors.lastname: Cote
authors.forename: Aaron A
authors.initials: AA
authors.lastname: Phillips
authors.forename: Heather J
authors.initials: HJ
authors.lastname: Foulds
authors.forename: Sarah A
authors.initials: SA
authors.lastname: Charlesworth
authors.forename: Shannon S D
authors.initials: SS
authors.lastname: Bredin
authors.forename: Jamie F
authors.initials: JF
authors.lastname: Burr
authors.forename: Michael S
authors.initials: MS
authors.lastname: Koehle
authors.forename: Darren E R
authors.initials: DE
authors.lastname: Warburton
mesh_terms: D000328:Adult; D017704:Baroreflex; D001808:Blood Vessels / Q000502:physiology; D005260:Female; D006321:Heart / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010807:Physical Endurance; D012420:Running / Q000502:physiology*; D012727:Sex Characteristics; D016277:Ventricular Function, Left