The junior elite female athlete is faced with the unique challenge of fuelling and hydrating for sport performance as well as growth and development. Very little published data have comprehensively described the nutrition and hydration status of adolescent female athletes, therefore, the aim of this study was to report fluid balance and sweat sodium concentration data, anthropometrics, hematological analysis as well as dietary intake of thirty-four junior elite female soccer athletes (15.7 ± 0.7 years). Hydration assessment (pre-training urine specific gravity, USG), fluid balance and sweat sodium concentration) was conducted during two 90 minute, on-field, group training sessions in mild/cool temperatures (9.8 ± 3.3 °C, 63.0 ± 12.4% relative humidity). Athletes completed four-day food records, hematological analysis (iron status markers, prealbumin and 25-hydroxyvitamin D), and anthropometric assessment. Results revealed mean body composition of players was 103.1 ± 35.2mm (sum of seven skinfolds) and 20.2 ± 5.4% body fat. The mean pre-training USG was 1.018 ± 0.009, with 45.4% of players in a hypohydrated state (USG >1.020). Players experienced a mean body mass loss of 0.84% ± 0.07%, sweat rates of 458.8 ± 284.9 ml/hour and sweat sodium concentration of 47.6 ± 11.9mmol/L during training sessions. Mean fluid intake within the 90 minute training sessions was 195 ± 0.24ml. Less than 1 litre of fluid was consumed by 100% of all participants during training sessions. Limited opportunity for fluid consumption was observed during training, with 6 of 7 sessions providing only a single fluid break. Mean energy intake was 2079 ± 460kcal/day. Mean macronutrient intake, carbohydrate (5.0 ± 1.6g/kg), protein (1.38± 0.3g/kg) and fat (29.9± 5.8%), met current Dietary Reference Intakes (DRIs) and sport nutrition recommendations however, 51.5% of athletes reported consuming <5g/kg carbohydrate. When compared to DRIs, mean intake of several micronutrients were below recommendations including pantothenic acid, vitamin D, folate, vitamin E, and calcium. The majority of athletes presented with serum 25-hydroxyvitamin D, prealbumin and iron markers within normal clinical ranges however when compared to recommendations for athletic populations, 89.3% and 50.0% of participants had suboptimal iron and 25-hydroxyvitamin D stores respectively. In summary, junior elite female soccer players experienced similar sodium losses and fluid losses to research reported in female adult players. The hypohydrated state, low consumption of fluids during training, which was typically devoid of sodium, and the limited access to fluids during training provide evidence of less than optimal hydration practices. Players were not in energy balance, and many athletes failed to meet carbohydrate and micronutrient requirements. When compared to recommendations for athletic populations, players may be at risk for iron depletion and suboptimal vitamin D status. More research is needed to confirm and support these findings and further develop an understanding of the unique nutrition and hydration needs of the female adolescent athlete. These findings can be used to inform nutrition and hydration practice guidelines and research for players, coaches and sport nutrition professionals.
| Identifer | oai:union.ndltd.org:uvic.ca/oai:dspace.library.uvic.ca:1828/3077 |
| Date | 15 October 2010 |
| Creators | Gibson, Jennifer |
| Contributors | Gaul, Catherine Ann |
| Source Sets | University of Victoria |
| Language | English, English |
| Detected Language | English |
| Type | Thesis |
| Rights | Available to the World Wide Web |
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