Blood phosphorus and magnesium levels in 130 elite track and field athletes

This study tested the clinical utility and relevance of serum phosphorus and magnesium as markers possibly useful to monitor training in athletes. Phosphorus and magnesium serum concentrations of 130 elite track and field athletes [65 males and 65 females, age range 20-30 years] from the National Athletics Sports Medicine Center database in Thessaloniki, Greece were measured. Abnormal results were found in 61 [47%] athletes [32 men and 29 women]. In male athletes, serum phosphate was higher than normal in 18% and decreased in 1.5%, whereas serum magnesium concentration was higher in 26%, and lower in 3%. Regarding female athletes, higher serum phosphate and magnesium levels were detected in 26% and 17% respectively, whereas decreased serum magnesium was found in 3%. The most common alterations were higher serum phosphate [29/61, 47%] and magnesium concentrations [28/61, 46%]. Abnormalities of serum phosphorus and magnesium concentrations were detected in almost half of the athletes. Hyperphosphataemia and hypermagnesaemia were the most common abnormalities. The reference intervals used for general population cannot be used for athletes. Given the lack of pathological manifestations, the physiopathological significance of these findings is uncertain. Further studies on the interpretation of reported ion concentrations in athletes should take in account the type of sport practiced and also the possible variations during the training and competition season

Body composition and dietary intake of elite cross-country skiers members of the Greek national team

To assess the anthropometric characteristics and dietary intake of the Greek national cross-country skiing team. Thirty-three athletes [10 females aged 20 +/- 5 years; 23 males aged 20 +/- 6 years old] participated in the study. All athletes were members of the Greek national ski team, and they had been selected to take part in the Winter Olympics, World Ski Championships, European Ski Championships or other international events, according to their performance. Body composition was estimated by bioelectrical impedance [BIA] and skinfold thickness. The athletes recorded their physical activity and dietary intake for 3 training days, and on a competition day. The female skiers had 14.2 +/- 1.9% body fat, the men 11.0 +/- 1.5% body fat. Female athletes consumed a diet of 1988 +/- 319 Kcal during training days and 2011 +/- 330 Kcal during competition days. Male athletes consumed 2255 +/- 790 Kcal and 2125 +/- 639 Kcal respectively. These values are below those recommended for highly active people. During the training period, carbohydrate, fat and protein contributed to 44.5 +/- 7.1%, 39.2 +/- 5.3% and 16.1 +/- 3.7% of the total energy intake [EI] respectively for the males, and to 52.8 +/- 5.6%, 33.0 +/- 3.7% and 14.3 +/- 2.5% of the EI of the women. Between training and competition days, men demonstrated an increased carbohydrate and reduced fat consumption when competing [P<0.001 for both]. Women, on the other hand, consumed more carbohydrate and less protein during competition days [P<0.05 for both]. Protein intake was within the recommended range for both males and females, but fat exceeded the recommended values and was consumed at the expense of carbohydrate. Vitamins B12, D, E and K, biotin, folate, Ca, Mg, K, I were inadequately consumed [below the RDA] by both women and men, while the women also exhibited inadequate intakes of iron and the men of manganese. The inadequate energy and nutrient intake in the Greek national cross-country ski team could put the athletes at risk of nutritional deficiencies, and possibly compromise their athletic performance