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Vitamin D is synthesised in the skin during exposure to sunlight and its fundamental roles are the regulation of calcium and phosphate metabolism and bone mineralisation. The aim of our study was to evaluate serum levels of 25-hydroxyvitamin D3, PTH and bone turnover markers (P1NP, OC, beta-CTx, OC/beta-CTx) and the intake of calcium and vitamin D in Polish Professional Football League (Ekstraklasa) players and in young men with a low level of physical activity. Fifty healthy men aged 19 to 34 years were included in the study. We showed that 25(OH)D3 and P1NP levels and OC/beta-CTx were higher in the group of professional football players than in the group of physically inactive men. The daily vitamin D and calcium intake in the group of professional football players was also higher. We showed a significant relationship between 25(OH)D3 levels and body mass, body cell mass, total body water, fat-free mass, muscle mass, vitamin D and calcium intake. Optimum 25(OH)D3 levels were observed in a mere 16.7% of the football players and vitamin D deficiency was observed in the physically inactive men. The level of physical activity, body composition, calcium and vitamin D intake and the duration of exposure to sunlight may significantly affect serum levels of 25(OH)D3.

Background: Both animal and human studies have proved that the dopaminergic system of the brain controls many aspects of behavior, e.g. motivation, addiction, motor movement, locomotion. It has been hypothesized that dopamine signalling may regulate spontaneous physical activity as well., Aim: Literature data suggests that an intact function of dopamine receptors (DRD2-DRD4) inhibits physical activity. This study searched for associations between a propensity to be active (or sedentary) and genetic variants of DRD2 and DRD4., Subjects and Methods: Invitations to participate in the study were sent to 900 randomly selected, adult men living in Lower Silesia, Poland. Genotyping of DRD2 C313T and DRD4 48-bp VNTR polymorphisms of enrolled subjects (371 (DRD2 C313T) and 397 (DRD4 48-bp VNTR)) was performed. Level of physical activity was evaluated using the International Physical Activity Questionnaire (IPAQ)., Results: No associations were found between level of physical activity (low, moderate, high) and the two polymorphisms: DRD2 C313T (p = 0.49) and DRD4 48-bp VNTR (p = 0.31). Studied subjects did not differ as to the number of hours spent sitting either., Conclusion: The results exclude the presence of significant relationships between polymorphic variants of the dopamine receptors genes and the level of physical activity in men.

Melanocortin plays an important role in the energy balance in humans. Actions of melanocortin are exerted through activation of five receptors among which the melanocortin-4 receptor (MC4R) is especially abundant within the central nervous system (CNS). It has been proved that genetic variations of the MC4R gene are associated with the energy intake. Recent data has suggested that MC4R gene polymorphism might influence physical activity/energy expenditure as well. Our aim was to search for associations between MC4R polymorphisms and the level of physical activity. We genotyped MC4R in a population-based cohort of 311 men. The level of physical activity was determined with use of the International Physical Activity Questionnaire. We have found that physical effort expressed as log METs-min/week (corrected for age, BMI and educational status) was 6.61 in men declaring low, 7.56-moderate and 8.96-high level of physical activity. We have not found any associations between the C-2745T MC4R polymorphism and the level of physical activity (P = 0.53). There were no interactions between the level of physical activity and the C-2745T polymorphisms either (P = 0.47). We conclude that the C-2745T genetic polymorphism of the MC4R gene does not influence the level of physical activity in healthy, adult men.

Concentrations of numerous hormones decrease with age. Some authors imply that a syndrome of partial endocrine deficiency may occur in the aging men. Among many lifestyle factors that influence hormonal status is physical activity. Especially interesting are relations between physical activity and the androgenic/estrogenic status of men. The aim of this study was to evaluate age-related changes of serum androgens, estradiol and SHBG in men presenting different levels of physical activity. Hormonal parameters were measured in a cohort of 387 healthy Caucasian men (aged from 24 to 72 years) from one administrative region of Poland. Their level of physical activity was determined by means of the International Physical Activity Questionnaire (IPAQ). We have found that contrary to SHBG concentration, total testosterone, free testosterone, bioavailable testosterone, calculated free testosterone and estradiol were negatively associated with age in the investigated subjects. Apart from estradiol, physical activity did not influence concentrations of the studied parameters. In younger (24-48 years), physically active males estradiol was significantly higher than in subjects characterized by a low level of physical activity. The situation was opposite in older males (48-72 years). In this age group low level of physical activity was associated with lower concentration of estradiol. Undertaking physical effort increased the decline of estradiol level with age.

Aim: Androgens influence human behavior. They affect sport performance, physical activity and emotional responses. CAG repeat polymorphism of androgen receptor (AR) gene is associated with transcriptional activity of AR. Decreased number of CAG repeats leads to increased androgen sensitivity. The purpose of this study was to investigate associations between AR CAG polymorphism and physical activity phenotype., Methods: Within the framework of the HALS Study we randomly selected 900 adult Caucasian males from one administrative region of Poland (Lower Silesia). Eventually, AR CAG repeat was genotyped by a PCR based assay in 360 male subjects. International Physical Activity Questionnaire (IPAQ) was used to determine the level of physical activity of studied subjects. It was expressed as multiples of resting metabolic rate by minutes of performance during a week (METs-minute/week)., Results: No association between AR CAG repeat polymorphism and physical activity (P=0.2, ANOVA) was observed. Men with short CAG presented the lowest level of physical activity reaching 3.44 log (METs-minute/week) (SE 0.053; 95% CI, 3.34-3.54), while in men with medium and long CAG it was respectively 3.58 (SE 0.063; 95% CI, 3.46-3.71) and 3.52 (SE 0.039; 95% CI, 3.44-3.60) log (METs-minute/week)., Conclusions: There is no association between AR CAG repeat polymorphism and the level of physical activity in healthy men.

Physical activity is known to exert beneficial effects on general health status of young, adult and elderly populations. Exercise (aside from genetic, hormonal, nutritional and pathological factors) also influences bone mineral density (BMD). Unfortunately, the association between physical exercise and BMD in adult population is controversial. Our aim was to assess relations between recreational physical activity and BMD in middle-aged men. We performed densitometry and hormonal measurements (total testosterone, free testosterone, dehydroepiandrosterone sulfate, estradiol) in a homogenous group of 38 subjects. Among them, we distinguished 22 who had not engaged in any physical activity, and 16 who had recreationally exercised for about 10 years. Both groups did not differ in regard to hormonal status. Similarly, densitometry did not reveal any statistically significant differences in BMD between both groups of men. Upon our observation, we can hypothesize that recreational physical activity does not affect bone mineral density in middle-aged men.