Affiliations: [a] Department of Life Sciences, Anglia Ruskin University,
Cambridge, UK | [b] Department of Physiology, Development and
Neuroscience, University of Cambridge, Cambridge, UK
Note: [] Corresponding author: Dan Gordon, Department of Life Sciences,
Anglia Ruskin University, East Road, Cambridge CB1 1PT, UK. Tel.: +44 845
1962774; Fax: +44 845 1962774; E-mail: dan.gordon@anglia.ac.uk
Abstract: BACKGROUND: There are alterations in strength in relation to
menstrual cycle phase but little data attributing these responses to female sex
hormone levels using a pseudo-menstrual cycle group as control. OBJECTIVE: Examining the effects of menstrual cycle phase on the development
of peak torque across a range of isokinetic speeds. METHOD: 17 well trained females, 11 formed the non-oral contraceptive group (n-OC) (age 20.7
± 1.4 yrs, mass 59.2 ± 6.9 kg, height 166.8 ± 7.1 cm) and 6 the
oral contraceptive control group (OC) (age 20.3 ± 0.5 yrs, mass 60.5 ±
4.2 kg, height 164.8 ± 4.8 cm). Concentric strength of the knee flexors
and extensors (60–240°/s) was assessed, corresponding to menstruation
(MEN), mid-follicular (mFOL), mid-luteal (mLUT) and pre-menstrual (pMEN). RESULTS: For n-OC significant decreases in peak torque production of the
extensors at 120°/s (P=0.0207) (MEN) and of the flexors at
60°/s (P=0.0116) (MEN) and 120°/s (P=0.0282) (MEN)
were observed compared to pMEN. No significant differences were observed across
any menstrual cycle phase and peak torque for the OC group (p> 0.05).
Significant positive correlations were observed (mLUT) between peak torque and
oestrogen at 60°/s (P=0.040) and 120°/s (P=0.031). CONCLUSIONS: There are significant fluctuations in peak torque of the
knee extensors in response to phases of the menstrual cycle associated with
variances in the female sex hormones. The findings have implications for the
planning of strength training in female athletes.
Keywords: Peak torque, menstruation, oestrogen, force production
