MRI reveals menstrually-related muscle edema that negatively affects athletic agility in young women

<div><p>Context</p><p>About 10% of Japanese female athletes are afflicted by menstrually-related edema, mainly in the lower limbs, and, with few studies on this problem, the effect on performance remains unclear.</p><p>Objective</p><p>To quantitatively evaluate fluid retention in the calf in female students over their menstrual cycle using magnetic resonance imaging (MRI) and to determine the relationship of MRI changes and athletic performance.</p><p>Design</p><p>The menstrual cycle was divided into 5 phases: menstrual, follicular, ovulatory, early luteal, and late luteal with sampling done in either morning (AM) or afternoon (PM) sessions. At each phase, MRI of the calf (7:00–8:00, 14:00–16:00), body composition and hormones (7:00–8:00), and athletic performance (14:00–16:00) were evaluated.</p><p>Participants</p><p>13 adult healthy Japanese female students with eumenorrhea.</p><p>Results</p><p>Estradiol levels decreased significantly in the menstrual phase and the follicular phase compared to the early luteal phase (<i>P</i> = 0.001, <i>P</i> = 0.024 respectively). Menstrual phase estradiol levels were significantly lower compared to the ovulatory phase (<i>P</i> = 0.015), and the late luteal phase (<i>P</i> = 0.003). Progesterone levels decreased significantly in the menstrual phase and the follicular phase compared to the ovulatory phase (<i>P</i> = 0.012, <i>P</i> = 0.009 respectively), the early luteal phase (both <i>P</i> = 0.007), and the late luteal phase (<i>P</i> = 0.028, <i>P</i> = 0.029 respectively), and it along with a significant decrease in the ovulatory phase compared to the early luteal phase (<i>P</i> = 0.010). AM T2 signals were significantly lower in the menstrual phase compared to the ovulatory phase (<i>P</i> = 0.043) but not other phases. PM T2 signals increased significantly in the menstrual phase compared to the follicular phase (<i>P</i> = 0.003), ovulatory phase (<i>P</i> = 0.009), and the late luteal phase (<i>P</i> = 0.032), and the difference between the AM and PM values increased significantly in the menstrual phase compared to the other 4 phases (<i>P</i><0.01). A negative correlation between fluid retention and agility was observed.</p><p>Conclusion</p><p>In female students fluid retention during the menstrual phase could be a factor that influences athletic agility.</p></div

MRI reveals menstrually-related muscle edema that negatively affects athletic agility in young women - Fig 3

<p>Outer peripheral area (A, cm²) and rectangular area of sway (B, cm²). Scale bar: 1 cm.</p

Hormone levels in blood over the 5 phases.

<p>Hormone levels in blood over the 5 phases.</p

Variations in the athletic performance indexes over the menstrual cycle.

<p>Variations in the athletic performance indexes over the menstrual cycle.</p

Assessment of fluid retention in the calf.

<p>Assessment of fluid retention in the calf.</p

T2 signal and lateral cross-section area of the lateral gastrocnemius.

<p>T2 signal and lateral cross-section area of the lateral gastrocnemius.</p

Flow of the measurements in each phase of the day.

<p>Flow of the measurements in each phase of the day.</p