One in three women volleyball players showed signs of running short on fuel. Most of them had no warning signs around eating at all

Sports medicine has a plain name for an athlete who is not eating enough for the work she does: low energy availability. After training has taken its share, too little energy is left over to run everything else, and if that goes on for long enough the body starts to cut back. Periods can become irregular or stop, the gut can play up, injuries can come more often and performance can slide. The severe, long-running form is called relative energy deficiency in sport, or REDs.

Most of the research on this has been done in sports where being light or lean is part of the job: distance running, gymnastics, dance, sports with weight classes. Team sports have had less attention, and volleyball very little. A study published in PLOS One on 8 October 2026 went looking there.

Three sports scientists at two Turkish universities sent an anonymous online survey to female volleyball players through their coaches in May and June 2025. In all, 213 players answered: 60 from the women's first league, 110 from the second league and 43 from under-17 and under-19 squads. Their average age was about 20, and they trained for about 13 hours a week.

The survey carried two questionnaires that are widely used with athletes. The first, known as LEAF-Q, has 25 questions about stomach and bowel trouble, injuries and periods, the kinds of problems that tend to follow under-fuelling. It never asks what a player eats. A score of 8 or more counts as at risk. The second, EAT-26, has 26 questions about attitudes to food, dieting and weight, and a score of 20 or more is taken as a sign of disordered eating. Neither is a diagnosis. Each one is a flag that says this person is worth a closer look.

On the first questionnaire, 71 of the 213 players, one in three, scored in the at-risk range. That share was almost the same in the first league (32%), the second league (33%) and the youth squads (37%). On the second, 37 players, about one in six, were flagged for disordered eating. Here the levels looked different: 8% in the first league, 24% in the second and 14% among the youth players. The authors treat that gap between the two leagues as tentative, because they did not adjust for age, body size or training load.

The more interesting result is how the two flags overlapped. Players flagged for disordered eating were more likely to be flagged for under-fuelling as well: 22 of the 37, or 59%, against 28% of everyone else. So the two do travel together. But read it from the other side. Of the 71 players flagged for under-fuelling, 49 had an ordinary score on the eating questionnaire. That is more than two in three.

The study cannot say why, because it did not measure what anyone ate or how much energy they burned. The authors point to the standard explanation: an athlete can fall short without restricting anything on purpose, simply because her meals have not kept up with her training. Two other readings fit the data just as well. People can under-report on eating questionnaires, even anonymous ones. And the under-fuelling questionnaire picks up symptoms, such as a bloated stomach or a string of injuries, that can have other causes entirely.

One detail points the same way. Higher scores on the eating questionnaire went with more reported gut trouble and more injuries, but not with period problems. The authors warn against reading much into that, since they had little information on hormonal contraception, which changes bleeding patterns.

The limits are large, and the paper is open about them. The players were whoever responded after a coach passed on the link, so these are not national rates and the authors say they should not be read as such. Everything was self-reported at one point in time. Nobody was examined, no food diaries were kept, and no blood or bone tests were done. The questionnaires have had little testing in players under 18, who made up part of the sample.

What is left is a modest, practical point for anyone who coaches, parents or is a young sportswoman. An athlete with a healthy relationship with food can still be eating too little for her training load. Asking only about dieting and body image would have missed most of the players this survey flagged. The questions about periods, recurring injuries and stomach trouble found them. A flag on either questionnaire is a reason to see a sports doctor or dietitian, and nothing more than that.