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  • Author: Margo L. Mountjoy x
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Jennifer Sygo, Alexandra M. Coates, Erik Sesbreno, Margo L. Mountjoy and Jamie F. Burr

Low energy availability (LEA), and subsequent relative energy deficiency in sport, has been observed in endurance, aesthetic, and team sport athletes, with limited data on prevalence in athletes in short-burst activities such as sprinting. We examined prevalence of signs and symptoms of LEA in elite female sprinters at the start of the training season (PRE), and at the end of a 5-month indoor training period (POST). Four of 13 female sprinters (31%) presented at PRE testing with at least one primary (amenorrhea, low bone mineral density, low follicle-stimulating hormone, luteinizing hormone, or estradiol, resting metabolic rate ≤29 kcal/kg fat-free mass, Low Energy Availability in Females Questionnaire score ≥8) and one secondary indicator of LEA (fasting blood glucose <4 mmol/L, free triiodothyronine <3.5 pmol/L, ferritin <25 μg/L, low-density lipoprotein cholesterol >3.0 mmol/L, fasting insulin <20 pmol/L, low insulin-like growth factor-1, systolic blood pressure <90 mmHg, and/or diastolic blood pressure <60 mmHg). At POST, seven out of 13 athletes (54%) presented with at least one primary and one secondary indicator of LEA, three of whom had also presented with indicators of LEA at PRE. Five out of 13 (39%) athletes had previous stress fracture history, though this was not associated with current indicators of LEA (PRE: r = .52, p = .07; POST: r = −.07, p = .82). In conclusion, elite female sprinters may present with signs and symptoms of LEA, even after off-season rest. Medical and coaching staff should be aware of the signs and symptoms of LEA and relative energy deficiency in sport and should include appropriate screening and intervention strategies when working with sprinters.

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Margo L. Mountjoy, Louise M. Burke, Trent Stellingwerff and Jorunn Sundgot-Borgen

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Ronald J. Maughan, Louise M. Burke, Jiri Dvorak, D. Enette Larson-Meyer, Peter Peeling, Stuart M. Phillips, Eric S. Rawson, Neil P. Walsh, Ina Garthe, Hans Geyer, Romain Meeusen, Luc van Loon, Susan M. Shirreffs, Lawrence L. Spriet, Mark Stuart, Alan Vernec, Kevin Currell, Vidya M. Ali, Richard G.M. Budgett, Arne Ljungqvist, Margo Mountjoy, Yannis Pitsiladis, Torbjørn Soligard, Uğur Erdener and Lars Engebretsen

Nutrition usually makes a small but potentially valuable contribution to successful performance in elite athletes, and dietary supplements can make a minor contribution to this nutrition program. Nonetheless, supplement use is widespread at all levels of sport. Products described as supplements target different issues, including the management of micronutrient deficiencies, supply of convenient forms of energy and macronutrients, and provision of direct benefits to performance or indirect benefits such as supporting intense training regimens. The appropriate use of some supplements can offer benefits to the athlete, but others may be harmful to the athlete’s health, performance, and/or livelihood and reputation if an anti-doping rule violation results. A complete nutritional assessment should be undertaken before decisions regarding supplement use are made. Supplements claiming to directly or indirectly enhance performance are typically the largest group of products marketed to athletes, but only a few (including caffeine, creatine, specific buffering agents and nitrate) have good evidence of benefits. However, responses are affected by the scenario of use and may vary widely between individuals because of factors that include genetics, the microbiome, and habitual diet. Supplements intended to enhance performance should be thoroughly trialed in training or simulated competition before implementation in competition. Inadvertent ingestion of substances prohibited under the anti-doping codes that govern elite sport is a known risk of taking some supplements. Protection of the athlete’s health and awareness of the potential for harm must be paramount, and expert professional opinion and assistance is strongly advised before embarking on supplement use.