1. Mountjoy, M., et al., International Olympic Committee (IOC) Consensus Statement on Relative Energy Deficiency in Sport (RED-S): 2018 Update. Int J Sport Nutr Exerc Metab, 2018. 28(4): p. 316–331.
  2. Loucks, A.B., Callister R., Induction and prevention of low-T3 syndrome in exercising women. Am J Physiol, 1993. 264(5 Pt 2): p. R924–30.
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  4. Halliday, T.M., J.P. Loenneke, and B.M. Davy, Dietary Intake, Body Composition, and Menstrual Cycle Changes during Competition Preparation and Recovery in a Drug-Free Figure Competitor: A Case Study. Nutrients, 2016. 8(11).
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  1. Great article and a very interesting concept. Thanks for posting it! I’m hoping you can clear some things up for me, though.

    First, regarding the case study of the female bodybuilder not regaining her cycle despite regaining lost weight post-competition, is the idea that she was somehow maintaining a leaner physique even though she weighed the same, or perhaps that she was doing far more training post-contest compared to pre-contest? If she regained the weight, then how would she be in RED unless it was one of those two cases?

    Second, 10-12 cal/lb seems like a pretty common cutting target for men, and yet that would seemingly put you below the EA threshold for developing RED-S if you’re training. Is the idea here that you’d get the cut over with before RED sets in? Or something else? Is there much data on how long RED takes to set in, or is there something I’m misunderstanding? Thank you!

    1. Hi D., sorry for missing this. I’ve pinged Eric who is better equipped to answer. His day for answering comments is Monday so check back on Tuesday.

    2. D – relative energy deficiency can occur at any body weight or body composition. Let’s say you got ready for a show, binged for 3 weeks, put back on most of the weight, and then went through a long phase of on and off periods of being in a caloric deficit and then surplus over time, in a cyclical fashion, constantly coming in and out of a deficit. You’d be in a state of frequent restriction and low energy availability, and could very easily result in not having a menstrual cycle return. After three weeks you also haven’t seen a full recovery of sex and metabolic hormone levels, which while they would come up a good bit from the initial weight gain, sometimes take months to completely recover. So it’s not just body weight or body comp, it’s what you have to do to get/stay there.

      Secondly, almost anyone who diets reaches a state of low energy availability, it’s not a matter of getting in and out before it sets in, or avoiding it. Rather, it’s mitigating it as much as possible and understanding what are reasonable expectations; i.e. someone overweight trying to achieve a healthier weight should take a moderate approach and probably take a diet break when symptoms crop up, and then do another block of dieting after. A competitor, may not have that luxury and should understand that eventually, they will experience many of the symptoms, even doing everything right, and that then the focus becomes recovery afterwards.

      It’s not an on and off switch, it’s a continuum related to the severity of the energy availability, and the time spent in a state of low energy availability.

      Hope this helps. If you have additional questions here is the IOC position stand most updated https://bjsm.bmj.com/content/52/11/687.share it’s a free full text

    1. I wouldn’t say it’s very useful to think like that, because you could just be at caloric maintenance in a normal metabolic state. In which case, the vast majority of people would be said to have a symptom of REDS.

      If you increase calories and didn’t gain weight, that would be a sign of it.

  2. Great article on a topic that is really important as the internet encourages more people – even non-bodybuilders – to keep chasing lower body fat percentages. I found the following quote the most interesting: “an energy deficit does result in decreased production of metabolic and sex hormones in both men and women, but what is critical to understand is this can occur at energy balance (caloric maintenance, where weight is maintained) as well.” Is it an accurate summary to say that maintaining weight is not the key to avoiding hormonal downturn, rather maintaining weight at an “appropriate” body fat percentage is key?

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