title: Heat stress does not exacerbate tennis-induced alterations in physical performance.
abstract: OBJECTIVE
  To assess the time course of changes in physical performance in response to match-play tennis under heat stress.
  
  
  METHODS
  Two matches consisting of 20 min of effective playing time (2×10 min segments) were played in COOL (∼102 min; ∼22°C and 70% relative humidity (RH)) and HOT (∼119 min; ∼36°C and 35% RH) environments. Repeated-sprint ability (3×15 m, 15 s rest), 15 m sprint time with a direction change (180°), vertical jump height (squat and countermovement jumps) and leg stiffness (multirebound jumps) were assessed in 12 competitive male players prematch, midmatch and postmatch, and 24 and 48 h after match completion.
  
  
  RESULTS
  During the repeated-sprint ability test, initial (+2.3% and +3.1%) and cumulated sprint (+1.5% and +2.8%) times increased from prematch to midmatch and postmatch, respectively (p<0.001), while the sprint decrement score did not change. Match-play tennis induced a slowing (average of both conditions: +1.1% and +1.3% at midmatch and postmatch time points; p=0.05) of 15 m sprint time with direction change. Compared with prematch, leg stiffness (-6.4% and -6.5%; p<0.001) and squat jump height (-1.5% and -2.4%; p=0.05), but not countermovement jump height (-0.7% and -1.3%; p>0.05), decreased midmatch and postmatch, respectively, regardless of the condition. Complete recovery in all physical performance markers occurred within 24 h.
  
  
  CONCLUSIONS
  In tennis, match-related fatigue is characterised by impaired repeated-sprint ability, explosive power and leg stiffness at midmatch and postmatch, with values restored to prematch baseline 24 h into recovery. In addition, physical performance responses (match and recovery kinetics) are identical when competing in cool and hot environments.
authors.affiliation: Athlete Health and Performance Research Centre, ASPETAR, Qatar Orthopaedic and Sports Medicine Hospital, Doha, Qatar.
authors.forename: Olivier
authors.initials: O
authors.lastname: Girard
authors.forename: Ryan J
authors.initials: RJ
authors.lastname: Christian
authors.forename: Sébastien
authors.initials: S
authors.lastname: Racinais
authors.forename: Julien D
authors.initials: JD
authors.lastname: Périard
mesh_terms: D054874:Athletic Performance / Q000502:physiology; D003080:Cold Temperature; D005221:Fatigue / Q000503:physiopathology; D018882:Heat Stress Disorders / Q000503:physiopathology; D006358:Hot Temperature; D006801:Humans; D008297:Male; D053580:Muscle Strength / Q000502:physiology; D018482:Muscle, Skeletal / Q000502:physiology; D063806:Myalgia / Q000209:etiology / Q000503:physiopathology; D012420:Running / Q000502:physiology; D013715:Tennis / Q000502:physiology*; D013997:Time Factors; D055815:Young Adult
keywords: Adaptations of skeletal muscle to exercise and altered neuromuscular activity; Biomechanics; Dehydration; Fatigue; Thermoregulation