title: Oral contraceptives do not affect muscle strength and hop performance in active women.
abstract: OBJECTIVE
  The primary aim of this study was to compare muscle strength in the upper and lower limb, as well as hop performance during oral contraceptive (OC) use with non-OC use in the same woman. A secondary aim was to compare muscle strength and hop performance within 3 specific phases of an OC cycle, as well as during a menstrual cycle of the corresponding cycle days (non-OC cycle).
  
  
  METHODS
  Crossover.
  
  
  METHODS
  Research laboratory.
  
  
  METHODS
  Seventeen moderate to highly recreationally active women participated in the study.
  
  
  METHODS
  Observational study with no intervention.
  
  
  METHODS
  Maximal isokinetic muscle strength of knee extensors, isometric handgrip strength, and 1-leg hop test for distance were measured during 1 OC cycle and 1 non-OC cycle at 3 specific phases, respectively, using a crossover design.
  
  
  RESULTS
  No significant differences were found in terms of muscle strength and hop performance between the OC cycle and the non-OC cycle. Furthermore, no significant difference in muscle strength and hop performance could be demonstrated within the OC cycle or within the phases of the menstrual cycle except from maximal isokinetic muscle strength in the knee extensors detected between the early follicular phase and the luteal phase.
  
  
  CONCLUSIONS
  We found no support for any significant influence of OC use on muscle strength and hop performance in healthy moderately active women.
authors.affiliation: Department of Neurobiology, Care Sciences and Society, Division of Physiotherapy, Karolinska Institutet, Huddinge, Sweden. linda.ekenros@ki.se
authors.forename: Linda
authors.initials: L
authors.lastname: Ekenros
authors.forename: Angelica Lindén
authors.initials: AL
authors.lastname: Hirschberg
authors.forename: Annette
authors.initials: A
authors.lastname: Heijne
authors.forename: Cecilia
authors.initials: C
authors.lastname: Fridén
mesh_terms: D000328:Adult; D054874:Athletic Performance / Q000502:physiology*; D003278:Contraceptives, Oral, Hormonal / Q000378:metabolism / Q000494:pharmacology*; D018592:Cross-Over Studies; D004967:Estrogens / Q000097:blood; D005260:Female; D018737:Hand Strength; D006801:Humans; D008597:Menstrual Cycle / Q000502:physiology; D053580:Muscle Strength / Q000187:drug effects* / Q000502:physiology; D011372:Progestins / Q000097:blood; D013548:Sweden; D055815:Young Adult
chemical_list: D003278:Contraceptives, Oral, Hormonal; D004967:Estrogens; D011372:Progestins