Vitamin D (25(OH)D) insufficiency and deficiency are highly prevalent in adult soccer players and can exceed 80% even in regions with high insolation; however, the treatment of this condition is often complicated. The aim of the present study was to examine the prevalence of vitamin D insufficiency and deficiency in youth Russian soccer players and the efficacy of its treatment. Participants were 131 young male football players (age 15.6 ± 2.4 years). Low vitamin D levels (below 30 ng/mL) were observed in 42.8% of the analyzed participants. These athletes were split in two groups composed of persons with vitamin D deficiency (serum vitamin D below 21 ng/mL) and insufficiency (serum vitamin D in range of 21–29 ng/mL). A dietary supplement of 5000 IU cholecalciferol per day was administered for two months. After the treatment, an average 92% increase in vitamin D concentration was observed (before treatment—19.7 ± 5.4 ng/mL, after treatment—34.7 ± 8.6 ng/mL, p < 0.001) and 74% of the post-treatment values were within the reference range (30–60 ng/mL). Serum concentration of vitamin D increased by 200% ± 98% (p < 0.001) during the first month of treatment with vitamin D deficiency and insufficiency being successfully treated in 83% of the football players. In summary, the prevalence of vitamin D insufficiency and deficiency was high in young Russian soccer players. Furthermore, it was indicated that the daily usage of cholecalciferol in a dose 5000 IU was an effective and well-tolerated treatment for vitamin D insufficiency. No linear dependency between the duration of treatment and increase in vitamin 25(OH)D concentration was observed.

There is now compelling evidence of the effectiveness of a range of post-exercise recovery techniques, including extended nights of sleep, cold water immersion, massage, and compression garments. Currently, limited information is available on post-exercise recovery methods used by elite endurance athletes. Therefore, this study investigated the actual methods of recovery used in this group of athletes. Google Forms were used to collect information on the recovery methods used by elite endurance track and field athletes (n = 153, 61.4% men, 38.6% women; average age: 22.7 ± 4.6 years). The most used methods of recovery were sauna bathing (96.7%), massage (86.9%), daytime nap (81.0%), and long night sleep (at least 9h) (61.4%). Recovery methods with proven effectiveness such as cold water immersion and compression garments were rarely used (15.0% and 7.8%, respectively). Overall, recovery methods were used more often when the tiers of the track and field athletes were higher. Massage and sauna bathing were the most used methods of post-exercise recovery among Russian endurance track and field athletes. In most cases, they were used in conjunction with short daytime nap and long night sleep. Higher tier athletes were more likely to use sauna bathing, massage, long night sleep, and daytime nap but not cold water immersion and compression garments as recovery methods; however, all these methods except for cold water immersion were widely used among elite-tier athletes.

Background: Vitamin D insufficiency is prevalent among athletes, and it can negatively affect physical performance. At the same time, most of the available data were obtained from untrained individuals of various ages, and published studies performed in athletes led to contradictory conclusions. Methods: This cohort prospective study examined the serum concentration of 25-hydroxycalciferol (25(OH)D) and its association with running speed and muscle power in 131 young football players (mean age 15.6 ± 2.4 years). Results: 25(OH)D levels were below reference in 42.8% (serum 25(OH)D <30 ng/mL) and above reference in 30.5% of the participants (serum 25(OH)D 61–130 ng/mL). A comparison of the results of 5, 15, and 30 m sprint tests and the standing long jump test found no statistically significant differences between the two groups. Athletes from the 25(OH)D-insufficient group were treated with 5000 IU cholecalciferol supplement daily for 60 days. After the treatment, the 25(OH)D concentration increased by 79.2% and was within reference in 84% of the treated athletes (serum 25(OH)D 30–60 ng/mL). Testing was repeated after the end of treatment, and a statistically significant increase in the results of the 5, 15, and 30 m sprint tests was observed (Cohen’s d was 0.46, 0.33, and 0.34, respectively), while the results of the standing long jump test remained unchanged. Body height, body weight, and lean body mass of the football players also increased. Conclusions: These findings indicate that there is likely no correlation between serum levels of 25(OH)D, muscle power, and running speed in young professional football players, and the changes observed post-treatment might have been caused by changes in the anthropometric parameters. During the study, all the anthropometric parameters changed, but the amount of lean body mass only correlated with the results of the 5 m sprint.