The effect of combined supplementation of carbohydrates and creatine on anaerobic performance.

The purpose of the study was to examine the effect of creatine (Cr) supplementation on anaerobic performance when ingesting creatine and carbohydrates (CHO) together. Twenty male physical education students comprised the two experimental (CR and CRCHO) and one control (CON) groups of the study. All groups performed three 30 s anaerobic Wingate tests (AWTs) interspersed with 6 minutes of recovery. The CR group (n = 7) ingested 5 g of Cr 5 times per day for 4 days. Subjects in the CRCHO group (n = 6) ingested the same quantity but additionally after each 5 g dose of Cr consumed 500 ml of a commercially available energy drink containing 100 g of simple sugars. Over all three AWTs average mean power improved significantly compared to baseline for the CR group (5.51%) but not for the CRCHO group (3.06%). Mean power for the second AWT was improved following the acute loading for the CR group only (4.54%) and for the third AWT for both CR (8.49%) and CRCHO (5.75%) groups. Over all three AWTs a significant change was recorded in average peak power following the acute loading for the CR group (8.26%) but not for the CRCHO group (4.11%). Peak power was significantly improved following the loading only for the CR group during the third AWT (19.79%). No changes in AWT performance were recorded for the CON group after intervention. The findings of the present study suggest that ingesting creatine together with carbohydrates will not further improve performance compared to the ingestion of creatine only.

Differences in energy and nutrient-intake among Greek children between 1992/93 and 2006/07.

BACKGROUND: There is lack of data in Greece on the trends in energy and nutrient intake. The present study aimed to examine differences in these parameters among first-grade children of Crete, Greece, between 1992/93 and 2006/07. METHODS: Children (aged 5.7-7.6 years) from two-representative cross-sectional samples participated during 1992/93 (n = 245) and 2006/07 (n = 257). Nutrient and food intakes were assessed using estimated 3-day-food records. Nutrient intakes were estimated as amounts per 4185 kJ (1000 kcal) of energy intake (EI), whereas macronutrients were estimated as percentage of total EI. RESULTS: Between 1992/93 and 2006/07, respectively, significant increases (P < 0.05) were observed in the intake of energy (boys: 7996 versus 8646 kJ; girls: 7265 versus 7963 kJ), calcium (boys: 488 versus 587 mg; girls: 464 versus 594 mg), iron (boys: 5.8 versus 7.3 mg; girls: 5.7 versus 7.4 mg) and vitamins B2 (boys: 1.01 versus 1.17 mg; girls: 1.0 versus 1.16 mg) and B6 (boys: 0.80 versus 0.87 mg; girls: 0.75 versus 0.95 mg), for boys and girls, respectively. Among boys, the intake of protein (13.6 versus 14.6% of EI) and total trans fatty acids (TTFA) (0.84 versus 0.99 g) was also significantly lower in 1992/93 (P < 0.016). Between 1992/93 and 2006/07, total fat (boys: 42.9% versus 42.8%, girls: 42% versus 43.1%) and saturated fat (boys: 15.5% versus 15.4%, girls: 15% versus 15.3%) exceeded the 30-35% and <10% dietary recommendations, respectively, A significantly higher proportion of children in 2006/07, compared to 1992/93, had a higher intake of total energy (>120% of the recommended energy allowance). CONCLUSIONS: The intake of several macronutrients (protein, TTFA, total and saturated fat) in this sample of children did not meet the recommended intakes in either time period.

Differences in food consumption according to weight status and physical activity levels among Greek children between 1992/93 and 2006/07.

BACKGROUND: There is a lack of data in Greece on trends in food intake according to weight status and physical activity (PA), despite the high prevalence of obesity. The present study aimed to examine differences in these parameters among first-grade children from Crete, Greece, over a 15-year period. METHODS: Children (aged 5.9-7.6 years) from two representative cross-sectional studies participated during 1992/93 (n = 245) and 2006/07 (n = 257). Estimated 3-day food records were used to assess food consumption and energy-density (ED) [kJ g(-1) (kcal g(-1) )]. Moderate-to-vigorous-PA (MVPA) and cardiorespiratory-fitness were assessed by questionnaires and the 20-m shuttle-run test (20mSRT), respectively. RESULTS: In 2006/07, compared to 1992/93, both sexes had a significantly higher intake of dairy products and snacks (P < 0.001), a lower intake of cereals (P < 0.001) and higher cardiorespiratory fitness levels (P < 0.001). Among girls, fruit/vegetable consumption was higher (P < 0.05), although legume intake was lower (P < 0.005). Among overweight/obese (OW/OB) children, ED significantly decreased (P < 0.05) and the mean consumption of fruits/vegetables was higher (P < 0.001). The percentage of OW/OB boys was significantly higher (P < 0.001); however, MVPA was significant higher in this group compared to 1992/93 (P < 0.001). During the two time-periods, active children in 2006/07 appeared to have a lower ED than active ones in 1992/93 (P < 0.001). CONCLUSIONS: Several differences in food intake were observed among first-grade children of Crete between 1992/93 and 2006/07, as characterised by significant increases in the consumption of dairy products and snacks and a decrease in the intake of cereals, among both sexes. Future school-based interventions in this population should emphasise the need to increase fruit/vegetable, unrefined cereal and legume consumption.

The effect of longer-term creatine supplementation on elite swimming performance after an acute creatine loading.

We investigated the effect of an acute creatine loading (25 g per day for 4 days) and longer-term creatine supplementation (5 g of creatine or 5 g of placebo per day for 2 months) on the performance of 22 elite swimmers during maximal interval sessions. After the acute creatine loading, the mean of the average interval swim times for all swimmers (n = 22) improved (44.3+/-16.5 s before vs. 43.7+/-16.3 s after supplementation; P<0.01). Three of the 22 swimmers did not respond positively to supplementation. After 2 months of longer-term creatine supplementation or placebo, neither group showed a significant change in swimming performance (38.7+/-13.5 s before vs. 38.7+/-14.1 s after for the creatine group; 48.7+/-18.0 s before vs. 48.7+/-18.1 s after for the placebo group). We conclude that, in elite swimmers, 4 days of acute creatine loading improves swimming performance significantly when assessed by maximal interval sessions. However, longer-term supplementation for 2 months (5 g of creatine per day) did not benefit significantly the creatine group compared with the placebo group.