Semi-Professional Rugby Union Players May be at Risk of Low-Energy Availability

INTRODUCTION:
Rugby players should aim to consume enough food to meet energy, macronutrient and micronutrient requirements. Failure to do so can negatively impact performance, recovery, health, well-being, cognitive function and may increase injury risk. Provincial academy players in New Zealand typically present congested schedules; alongside developmental rugby athletes will train and play at the local club level and balance study and work commitments. As such, monitoring and management of dietary intake is crucial.
METHODS:
Nine semi-professional developmental rugby union players (age = 20.6 ± 1.7 years; height = 186.3 ± 9.0cm; body mass = 102.4 ± 18.2kg; fat free mass = 82.9 ± 12.1kg) recorded dietary intake over a 4-week pre-season using the remote food photography method. Body composition was assessed via three-dimensional optical scanning.
RESULTS:
A total of 76 days were sufficiently logged. A large variability in daily total nutrient intake was observed (Energy = 2550 ± 914 kcal, protein = 135 ± 50 grams, carbohydrate = 270 ± 122 grams, fat = 97 ± 42 grams). Energy intake relative to fat free mass (FFM) was 31 ± 11 kcal.kg FFM. Relative to total body mass, protein intake was 1.3 ± 0.4 grams and carbohydrate intake 2.6 ± 1.3 grams. Requirements for protein and carbohydrates were not met on 49.4 and 96.6% of eating occasions, respectively.
CONCLUSION:
Energy intake relative to FFM did not meet the proposed threshold of 40kcal.kg FFM to ensure optimal energy availability for physiological functions in male athletes [1]; previous research has demonstrated that high-level rugby players may expend 61 kcal.kg FFM daily [2]. Failure to meet the optimal threshold may result in physiological and metabolic dysfunction [3], impairment to adaptive responses to exercise and performance [1,3], increased risk of injury or illness [1,3] and a failure to meet macronutrient and micronutrient requirements [3]. Indeed, relative protein intake was at the low end of recommendations for athletes, potentially compromising FFM during periods of energy deprivation, which may be further exacerbated by inadequate energy intake [1]. Similarly, carbohydrate intake did not meet best-practice sports nutrition recommendations for rugby players.
Developing rugby players should take care to consume a high-quality diet that meets energy and macronutrient requirements to tolerate the demanding nature of the sport, promote adaptation and optimal health and decrease injury risk.

[1] Wasserfurth et al., 2020. Reasons for and consequences of low energy availability in female and male athletes: social environment, adaptations, and prevention. Sports med, 6(1), pp.1-14.
[2] Smith et al., 2018. Energy expenditure of rugby players during a 14-day in-season period, measured using doubly labelled water. Eur jour app phys, 118(3), pp.647-656.
[3] Logue et al., 2018. Low energy availability in athletes: a review of prevalence, dietary patterns, physiological health, and sports performance. Sports Med, 48(1), pp.73-96.