Dr Nicky Keay: Relative Energy Deficiency in sport
You have probably heard of the Female Athlete Triad. It was a concept formulated by Barbara Drinkwater in the late 80’s who observed that in a group of female athletes eating the same amount of calories, those with high training loads suffered from menstrual disruption and low bone mineral density.
Underlying the Female Athlete Triad concept is that the body needs energy to train but it also needs energy to carry out everyday executive functions and so-called housekeeping tasks such as bone and tissue renewal. Not fuelling enough and training hard means that the housekeeping and executive functions don’t function so well and probably you’re not going to function too well as an athlete either, although you might make your racing weight.
Because of its evolution from a study of females, this under-fuelling, or low energy was considered to be a female issue. However, in 2014 the IOC produced a consensus statement describing the model of Relative Energy Deficiency in Sport (REDS). The statement recognised that this was not an exclusively female issue and that the effects were far wider than just on menstruation and bones.
Dr. Nicky Keay, BA, MA (Cantab), MB BChir, MRCP is a physician and researcher with an extensive background in endocrinology and sports/exercise medicine. Her personal background as a ballet dancer and choreographer led to her long-standing interest in the effects of high-level training and inadequate nutrition on women’s health. She has been speaking on the Nourish Balance Thrive podcast about her research studying dancers and the long-term effects of REDS.
“My first question was what happens to these dancers once they’ve retired? I collected a group of retired professional dancers and put them all on a DEXA machine, which measures body composition, but more specifically for this study, hormonal density at the various sites in the body, the spine, the hip”.
What she found was concerning. If the retired dancers had experienced a menstrual issue whilst training, their periods had returned in retirement but their bone density at the lumbar spine was less than expected for their age. This was particularly marked if their periods had stopped from menarche and also if their weight had dropped substantially during their training.
“The conclusion of that study is that we are dealing with something, a low energy availability…..which not only affects the immediate health of an athlete but also, potentially has long-term consequences,” Keay tells NBT.
Keay also went on to conduct a three-year study with three groups of dancers. She found that the ones that were really doing heavy-duty exercise training were the ones that had problems with regular menstruation and had low bone mineral density. The highlight from this study is that if you disrupt your normal development and particularly your bone health when you’re young, it’s probably going to be difficult to recoup that and get up to adult levels.
“There have been several articles*, papers saying that really, we have to be careful of young athletes specializing too early and doing too much intensity or just one specific type of sport,” says Keay. “Because that’s not only an injury issue, but in this situation, if it’s a sport where you need to be lightweight, that also could have long-term consequences.”
Keay is now working on a study of cyclists. “My question was what’s the situation in amateur but good level, competitive male cyclists?” For female cyclists there is an obvious clinical sign, if her periods are not regular of reproductive age, then there’s a problem. I mean there’s a hormone problem. But you don’t really have this obvious thing in men. They don’t like to admit that they might have disordered eating or anxiety around food. It’s not really the male thing to do. I was wondering how am I going to detect those at risk of REDS. I use the faithful DEXA scan because that’s the gold standard when it comes to body composition and bone health, bone mineral density.”
One of the other problems with cycling, like rowing, is that it’s non-weight bearing. “Cycling is like swimming in that sense. You’re not putting force through your bones,” says Keay. “Your bones are very good at responding to an external load. But if you’re not subjecting the bones to that, then they’re not going to be very strong. Plus, on top of that, if you’re not supplying sufficient nutrition then the hormonal environment is not going to be very good.”
*Effect of exercise on adolescents; Study: Keay NJ, Frost M, Blake G, New S & Fogelman I (2000) Study of the factors influencing the bone mineral density in girls. Osteoporosis International 11: S1– 31; (being revised for publication).