title: Sex differences in pacing during 'Ultraman Hawaii'.
abstract: BACKGROUND
  To date, little is known for pacing in ultra-endurance athletes competing in a non-stop event and in a multi-stage event, and especially, about pacing in a multi-stage event with different disciplines during the stages. Therefore, the aim of the present study was to examine the effect of age, sex and calendar year on triathlon performance and variation of performance by events (i.e., swimming, cycling 1, cycling 2 and running) in 'Ultraman Hawaii' held between 1983 and 2015.
  
  
  METHODS
  Within each sex, participants were grouped in quartiles (i.e., Q1, Q2, Q3 and Q4) with Q1 being the fastest (i.e., lowest overall time) and Q4 the slowest (i.e., highest overall time). To compare performance among events (i.e., swimming, cycling 1, cycling 2 and running), race time in each event was converted inzscore and this value was used for further analysis.
  
  
  RESULTS
  A between-within subjects ANOVA showed a large sex × event (p= 0.015,η2= 0.014) and a medium performance group × event interaction (p= 0.001,η2= 0.012). No main effect of event on performance was observed (p= 0.174,η2= 0.007). With regard to the sex × event interaction, three female performance groups (i.e., Q2, Q3 and Q4) increased race time from swimming to cycling 1, whereas only one male performance group (Q4) revealed a similar trend. From cycling 1 to cycling 2, the two slower female groups (Q3 and Q4) and the slowest male group (Q4) increased raced time. In women, the fastest group decreased (i.e., improved) race time from swimming to cycling 1 and thereafter, maintained performance, whereas in men, the fastest group decreased race time till cycling 2 and increased it in the running.
  
  
  CONCLUSIONS
  In summary, women pace differently than men during 'Ultraman Hawaii' where the fastest women decreased performance on day 1 and could then maintain on day 2 and 3, whereas the fastest men worsened performance on day 1 and 2 but improved on day 3.
authors.affiliation: Gesundheitszentrum St. Gallen, St. Gallen, Switzerland; Institute of Primary Care, University of Zurich, Zurich, Switzerland.
authors.forename: Beat
authors.initials: B
authors.lastname: Knechtle
authors.affiliation: Exercise Physiology Laboratory , Nikaia , Greece.
authors.forename: Pantelis T
authors.initials: PT
authors.lastname: Nikolaidis
keywords: Cycling; Pacing; Running; Swimming; Triathlon; Ultra-endurance