Is the physical fitness of schoolchildren dependent on their physical activity levels and nutritional status? The experience from Serbia.

Introduction: based on the presumed relationship between physical activity and physical fitness, it seems reasonable to expect that being active would result in sufficient fitness levels. However, the relationship between physical activity and fitness is not so plausible and needs deeper exploration. Objectives: we conducted a study aimed at exploring: a) the potential variation in physical activity level by gender and school grade; and b) the effect of physical activity level, gender, and nutritional status on physical fitness test results.

[Seasonal alterations in serum iron levels in elite football players].

Introduction: It is very important to monitor levels of serum iron and other factors of iron metabolism and oxygen transport system as they play a very important role in functional ability of football players. A decrease in serum iron level can be the very first sign of development of iron deficiency anaemia, which seriously influences health and functional ability of an athlete and is a common problem in competitive sports.

Objective: The aim of this study was to observe and evaluate changes in serum iron values during the competition season in relation to the training process.

[Immune response to hepatitis B vaccine in elite athletes].

Introduction: Hepatitis B viral infection can create serious health problems, such as acute and chronic hepatitis, cirrhosis of liver and hepatocellular carcinoma. Athletes have bigger risk of hepatitis B infection due to frequent injuries with bleeding, their style of living (promiscuity), close contact with teammates, etc. The aim of this study was to investigate the immune response to hepatitis B vaccine among elite athletes, compared to corresponding control group of male subjects front general non-athlete population, and to test out reaction in relation to age.

[The significance of age and sex for the absence of immune response to hepatitis B vaccination].

Introduction: Seroepidemiological investigations after the administration of hepatitis B vaccine have shown that even 15% of vaccinated healthy persons do not generate immune response to the vaccines currently in use.

Objective: The aim of the research is to test the immunogenicity of hepatitis B vaccine in different age groups on the adult vaccinated population sample in Serbia.

Method: The tested general population sample consisted of 154 adult subjects.