VITAMIN D AND INJURIES IN DANCERS: A SYSTEMATIC REVIEW.

Vitamin D is involved in many different functions in the human body. Despite the well-known benefits of vitamin D and increasing trends of testing and supplementation, there is still a high prevalence of vitamin D deficiency worldwide, present in the general but also in the highly-active population such as athletes and dancers. Dancers are at a higher risk of vitamin D deficiency due to their long working hours spent indoors, without exposure to sunlight. The high level of workload and physical demands also put dancers at a high risk of injuries. The aim of this review was to systematically analyze the existing evidence on the association of vitamin D (serum level and supplementation) and injuries in dancers. Medline, Scopus, SportDiscus and Web of Science were searched to identify the available peer-reviewed articles. Five articles met the inclusion criteria (two interventional and three observational studies), three of which additionally investigated the relationship between vitamin D and muscle function. The reported results on positive influence of vitamin D serum level or vitamin D supplementation effect on reduced injury occurrence and enhanced muscular function in adolescent and elite professional ballet dancers are promising but the evidence is limited due to a low number of studies, small samples, and methodological limitations.

Whole-Body Vibration Effects on Flexibility in Artistic Gymnastics-A Systematic Review.

It is well documented that whole body-vibration training has effects on muscle strength and flexibility, blood circulation, decreases pain perception and strengthens bone and tendon. Although whole body-vibration has benefits in athletes' flexibility, we are not sure what its actual effects are in artistic gymnastics (since they already have stunning flexibility). Hence, the aim of this study was to analyse the studies on whole-body vibration in artistic gymnastics and to present the effects on flexibility. The search and analysis were carried out in accordance with PRISMA guidelines. The databases search (PubMed, Scopus, Google Scholar, Cochrane Library, ProQuest, EBSCOhost and Science Direct) yielded 18,057 potential studies. By the given inclusion criteria (studies from 2005 to 2022; full-text published in English; the study included male and female gymnasts as samples, and that participants were tested for evaluation of flexibility by whole-body vibration method), a total of 9 full-text studies were included, with a total of 210 participants, both male and female. As far as the measured flexibility tests conducted, front split, sit and reach and bridge were evaluated, while obtained results were 9.1-39.1%, 2.79-6.7%, 6.43-7.45%, respectively. All studies have conducted same vibration frequency (30 Hz) with same amplitude of displacements (2 mm), except for the one study who did not show the information of implemented amplitude. After analysing the obtained results, it can be concluded that the usage of whole-body vibration platform shows flexibility improvements in artistic gymnasts, both male and female. In addition, a combination of whole-body vibration and traditional static stretching may enhance the flexibility in artistic gymnasts. However, these results should be taken with caution. Since this review did not reveal the optimal vibrational protocol, it is necessary to invest time during the implementation of various vibrational experimental protocols, so future research is required.

The Impact of Sleep Deprivation on the Brain

Each sleep phase is characterized by specific chemical, cellular and anatomic events of vital importance for normal neural functioning. Different forms of sleep deprivation may lead to a decline of cognitive functions in individuals. Studies in this field make a distinction between total sleep deprivation, chronic sleep restriction, and the situation of sleep disruption. Investigations covering the acute effects of sleep deprivation on the brain show that the discovered behavioral deficits in most cases regenerate after two nights of complete sleep. However, some studies done on mice emphasize the possible chronic effects of long-term sleep deprivation or chronic restriction on the occurrence of neurodegenerative diseases such as Alzheimer's disease and dementia. In order to better understand the acute and chronic effects of sleep loss, the mechanisms of neural adaptation in the situations of insufficient sleep need to be further investigated. Future integrative research on the impact of sleep deprivation on neural functioning measured through the macro level of cognitive functions and the micro molecular and cell level could contribute to more accurate conclusions about the basic cellular mechanisms responsible for the detected behavioral deficits occurring due to sleep deprivation.