title: Effects of Ramadan on the diurnal variations of repeated-sprint performances.
abstract: OBJECTIVE
  This study examined the effects of Ramadan on cycling repeated-sprint ability (RSA) and corresponding diurnal variations.
  
  
  METHODS
  Twelve active men performed an RSA test (5 × 6-s maximal sprints interspersed with 24 s passive recovery) during morning and afternoon sessions 1 wk before Ramadan (BR), during the second (R2) and the fourth (R4) weeks of Ramadan, and 2 wk after Ramadan (AR). Maximal voluntary contraction was assessed before (MVCpre), immediately after (MVCpost), and 5 min after the RSA test (MVCpost5). Moreover, hematocrit, hemoglobin, and plasma sodium and potassium (K+) concentrations were measured at rest and after the RSA test and MVCpost.
  
  
  RESULTS
  Overall, peak power (Ppeak) during the RSA test decreased throughout the 5 sprints. Ppeak measured in the first sprint and MVCpre were lower during Ramadan than BR in the afternoon (P < .05) and higher in the afternoon than the morning BR and AR (P < .05). However, this diurnal rhythmicity was not found for the last 4 sprints' Ppeak, MVCpost, and MVCpost5 in all testing periods. Furthermore, the last 4 sprints' Ppeak, MVCpost, MVCpost5, and morning MVCpre were not affected by Ramadan. [K+] measured at rest and after the RSA test and MVCpost were higher during Ramadan than BR in the afternoon (P < .05) and higher in the afternoon than the morning during Ramadan (P < .05).
  
  
  CONCLUSIONS
  Fatigability is higher in the afternoon during Ramadan, and, therefore, training and competition should be scheduled at the time of day when physical performance is less affected.
authors.affiliation: High Inst of Sport and Physical Education, University of Sfax, Sfax, Tunisia.
authors.forename: Asma
authors.initials: A
authors.lastname: Aloui
authors.forename: Anis
authors.initials: A
authors.lastname: Chaouachi
authors.forename: Hamdi
authors.initials: H
authors.lastname: Chtourou
authors.forename: Del P
authors.initials: del P
authors.lastname: Wong
authors.forename: Monoem
authors.initials: M
authors.lastname: Haddad
authors.forename: Karim
authors.initials: K
authors.lastname: Chamari
authors.forename: Nizar
authors.initials: N
authors.lastname: Souissi
mesh_terms: D054874:Athletic Performance / Q000502:physiology*; D001835:Body Weight / Q000502:physiology; D002940:Circadian Rhythm / Q000502:physiology*; D002149:Energy Intake / Q000502:physiology; D015444:Exercise / Q000502:physiology; D005215:Fasting / Q000502:physiology*; D006693:Holidays; D006801:Humans; D007514:Islam; D008297:Male; D009119:Muscle Contraction / Q000502:physiology; D018763:Muscle Fatigue / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology; D011188:Potassium / Q000097:blood; D012420:Running / Q000502:physiology*; D055815:Young Adult
chemical_list: D011188:Potassium