title: Androgenicity of the progestin in oral contraceptives does not affect maximal leg strength.
abstract: OBJECTIVE
  This study was conducted to examine androgenicity of the progestin in oral contraceptive pills and its effect on maximal leg strength in females.
  
  
  METHODS
  Twelve participants who were using a monophasic pill containing 30 microg ethinylestradiol plus either 150 microg levonorgestrel (LEV) or 250 microg norgestimate (NOR) for at least the last 6 months were recruited (mean+/-SEM; LEV: age, 19.8+/-0.3 years; stature, 1.67+/-0.17 m; mass, 65.9+/-1.9 kg; NOR: age, 20.6+/-0.2 years; stature, 1.65+/-0.17 m; mass, 64.6+/-2.4 kg). Three maximal isokinetic extension and flexion tests were performed on three occasions (Days 3-6, 11-14 and 18-21 of the pill cycle) to assess peak extension and peak flexion torque (in Newton meters).
  
  
  RESULTS
  No significant (p>.05) differences were found in the LEV and NOR groups in peak extension torque (F=0.719; p=.416) or peak flexion torque (F=0.291, p=.601) throughout the pill cycle and between groups.
  
  
  CONCLUSIONS
  In this small study, the androgenicity of the progestin in the contraceptive pill had no significant association with maximal strength in these female athletes.
authors.affiliation: School of Sport and Health Sciences, The University of Exeter, Heavitree Road, Exeter, Devon EX1 2LU, UK. c.e.peters@ex.ac.uk
authors.forename: Charlotte
authors.initials: C
authors.lastname: Peters
authors.forename: Melonie
authors.initials: M
authors.lastname: Burrows
mesh_terms: D000328:Adult; D000728:Androgens / Q000494:pharmacology*; D003277:Contraceptives, Oral, Combined / Q000494:pharmacology*; D004997:Ethinyl Estradiol / Q000008:administration & dosage / Q000494:pharmacology; D015444:Exercise / Q000502:physiology; D005260:Female; D006801:Humans; D007866:Leg / Q000502:physiology; D016912:Levonorgestrel / Q000008:administration & dosage / Q000494:pharmacology; D053580:Muscle Strength / Q000187:drug effects*; D009644:Norgestrel / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000494:pharmacology; D045167:Progesterone Congeners / Q000008:administration & dosage / Q000494:pharmacology; D011372:Progestins / Q000494:pharmacology*; D013177:Sports
chemical_list: D000728:Androgens; D003277:Contraceptives, Oral, Combined; D045167:Progesterone Congeners; D011372:Progestins; D009644:Norgestrel; D004997:Ethinyl Estradiol; D016912:Levonorgestrel; C017576:norgestimate