A Modified Female Athlete Triad Identified in Male Runners

In the sports medicine community, there is still much debate on whether Female Athlete Triad or Relative Energy Deficiency in Sports (RED-S) is the correct term for a syndrome of interrelated condition that puts athletes at higher risk for bone stress injuries (BSI).

A new study, “Bone stress injuries in male distance runners: higher modified Female Athlete Triad Cumulative Risk Assessment scores predict increased rates of injury,” published in the February 2019 issue of the British Medical Journal of Sports Medicine, adds some insight to the debate with its findings that a modified Female Athlete Triad Cumulative Risk Assessment tool can help predict bone stress injury in male runners.

The researchers studied 156 male runners at two collegiate programs for a total of seven years using a mixed retrospective and prospective design. Point values were assigned using risk assessment categories including low energy availability, low body mass index (BMI), low bone mineral density (BMD) and prior bone stress injury.

According to the data, 42 of the 156 runners (27%) sustained 61 bone stress injuries over an average 1.9 years of follow-up. In the baseline risk factor model, each 1-point increase in prior bone stress injury score was associated with a 57% increased risk for prospective bone stress injury (p = 0.0042) and each 1-point increase in cumulative risk score was associated with a 37% increase in prospective bone stress injury risk (p = 0.0079).

In the longitudinal model, each 1-point increase in cumulative risk score was associated with a 27% increase in prospective bone stress injury risk (p = 0.05).

Aurelia Nattiv, M.D., a professor in the department of Family Medicine, Division of Sports Medicine and Non-Operative Orthopaedics and in the department of Orthopaedic Surgery at the University of California in Los Angeles, and Michael Fredericson, M.D., a professor of Orthopaedic Surgery at the Stanford University Medical Center in Stanford, told OTW:

“We evaluated variables of interest including low energy availability, disordered eating/eating disorder, low BMI, prior BSI and low BMD values. Each risk factor was quantified as low (0 point), moderate (1 point) or high risk (2 points) using a modified Female Athlete Triad Coalition Consensus Statement Cumulative Risk Assessment tool that excluded late menarche and history of oligomenorrhoea/amenorrhoea risk factors.

“We found that this modified version of the Female Athlete Triad Cumulative Risk Assessment score—including low EA, low BMI, prior BSI and low BMD values—was associated with prospective BSI in male runners. While cumulative risk factors for low bone mass have been reported in young male athletes, to our knowledge this investigation is the first to report cumulative risk factors being associated with a greater rate of BSI in male runners. Our findings may provide an evidence-based method to quantitatively evaluate male runners at elevated risk for BSI.”

On how this contributes to the Female Athlete Triad vs. RED-S debate, they added, “The findings in our study emphasizes and strengthens the parallels between the Female Athlete Triad, and male athletes (different from the concept of RED-S). The Female Athlete Triad has over 30 years of published evidence to support its existence in the scientific literature, and there is emerging evidence in young male athletes to support these parallels between the female and male athlete spectrums involving low energy availability, disruptions in the hypothalamic–pituitary–gonadal axis and increase in risk for bone stress injuries.”

“Our study supports these parallels, however, there is a paucity of scientific studies to support the broader concept of RED-S at this time, and further studies are needed.”