Relative energy deficiency in sport and athlete nutrition — branching viva

Branching framework

Open with the definition of energy availability and the threshold. Energy availability is the dietary energy intake minus the exercise energy expenditure, divided by the fat-free mass, expressed as kilocalories per kilogram of fat-free mass per day. The reproductive hormone pulsatility is disrupted when the energy availability falls below approximately thirty kilocalories per kilogram of fat-free mass per day, as the Loucks and Thuma experiment established, and the optimal function is sustained at approximately forty-five kilocalories per kilogram of fat-free mass per day and above. State these numbers aloud, because the examiner is listening for whether you hold the threshold that anchors the whole topic. [5]

Branch to the two frameworks. The Female Athlete Triad is the three spectra of the energy availability, the menstrual function, and the bone mineral density, operationalised by the 2014 Coalition Cumulative Risk Assessment into the low, the moderate, and the high risk. Relative energy deficiency in sport is the wider IOC web of the affected systems — the reproductive, the bone, the cardiovascular, the immune, the metabolic, the endocrine, the gastrointestinal, the psychological, and the growth — operationalised by the RED-S Clinical Assessment Tool, and it applies to the male as much as the female. Refuse the false choice between the two frameworks, because the comparison study confirmed that they place the high-risk athlete in the same restricted-from-play category. [4]

Branch to the risk stratification and the single most important management principle. This runner with the bone stress injury, the four-month amenorrhoea, and the falling body mass index is the high-risk athlete by the Cumulative Risk Assessment, and she is restricted from the training and the competition. The single most important management principle is the energy restoration, because it is the only treatment that reverses the functional hypothalamic amenorrhoea and rebuilds the bone. The Endocrine Society guideline frames the energy restoration as the first-line treatment, and the combined oral contraceptive pill is not the first-line treatment for the bone, because it does not restore the bone density and it masks the menstrual signal. Name this principle aloud, because the examiner probes it directly. [6] [4]

Branch to the bone density Z-score interpretation. The dual-energy X-ray absorptiometry is reported with the age-matched Z-score, never the T-score, in the paediatric and the adolescent athlete. A Z-score of negative two or below defines the low bone mineral density for the chronological age, and a Z-score between negative one and negative two with the risk factors of the energy deficit and the menstrual dysfunction is the concerning intermediate zone. The measurement is made at the lumbar spine, the trabecular site most affected by the energy deficit, and the repeat measurement tracks the response to the energy restoration over the year. [9]

Branch to the combined oral contraceptive pill question. The pill is the trap the examiner sets. It is prescribed to induce the withdrawal bleed and to protect the bone, but the induced bleed is not the menstrual recovery, and the pill does not restore the bone density in the energy-deficient athlete. The pill masks the menstrual signal, and the athlete and the family are falsely reassured that the deficit is resolved. The safeguard is the Endocrine Society guideline, which frames the energy restoration as the first-line treatment and reserves the pill for the contraception and the bone protection in the specific, counselled case where the energy restoration has failed. [6] [5]

Close with the male athlete and the high-risk dancer. The male athlete with the stress fracture and the low testosterone is captured by the RED-S framework, and the same energy-availability logic and the same multidisciplinary pathway apply. And the dancer with the drive for thinness, the falling weight, the prolonged amenorrhoea, and the bradycardia is the high-risk athlete with the eating disorder who demands the admission, the cardiac monitoring, and the supervised refeeding, and the sacral stress fracture is the high-risk site that is imaged urgently. The examiner rewards the candidate who frames the athlete assessment as the clinical reasoning exercise with the energy-restoration-first pathway and the high-risk restriction from play. [4] [9]