Associations of Vitamin D Levels with Physical Fitness and Motor Performance; A Cross-Sectional Study in Youth Soccer Players from Southern Croatia

Abstract

Vitamin D level is known to be a factor potentially influencing physical fitness, but few studies have examined this phenomenon among youth athletes. We aimed to evaluate the associations of vitamin D levels (as measured by 25-hydroxyvitamin D concentrations—25(OH)D) with various physical fitness and motor performance tests in youth football (soccer) players. This cross-sectional study included a total of 52 youth soccer players (15.98 ± 2.26 years old) from Southern Croatia. The participants were evaluated at the end of the winter period and data were collected of anthropometric measures (body mass and body height), vitamin D status (25(OH)D levels), physical fitness tests (sprints of 10 and 20 m, 20 yards test, the countermovement jump, the reactive strength index (RSI)) and motor performance tests (the soccer-specific CODS, the soccer-specific agility, and static balance). Among the studied players, 54% had 25(OH)D insufficiency/deficiency, showing a lack of 25(OH)D is widespread even in youth athletes living at a southern latitude. The 25(OH)D level was correlated with sprint 20 m, 20 yards tests, and RSI, showing a greater role of 25(OH)D in physical fitness tests where energetic capacity is essential than in sport-related motor performance tests where skills are crucial. Our results support the idea that vitamin D can play a determinant role in physical fitness tests with a clear physiological component, but is not crucial in motor performance tests related to specific sports where skills are a key component. Future studies should investigate the effects of vitamin D supplementation on the performance in physical fitness and motor performance tests among youth athletes.

Changes of 25(OH)D Concentration, Bone Resorption Markers and Physical Performance as an Effect of Sun Exposure, Supplementation of Vitamin D and Lockdown among Young Soccer Players during a One-Year Training Season

“…In contrast, Bezuglow et al [ 11 ] did not confirm such relations in young soccer players during the winter preparation period. Similarly, Montenegro et al [ 30 ] and Gilic et al [ 61 ] did not observe strength improvements after vitamin D supplementation.…”

The Effect of the T-Sprint Training Method and Zigzag Running on Increasing Speed, Endurance and Agility in U18 Footballers

“…Age [56], [57]. Agility increases until about 12 years of age when it begins to enter rapid growth spurts [58]. Then during the rapid growth period, agility did not increase but decreased [59].…”

Biological Mechanisms Underlying Physical Fitness and Sports Performance: An Editorial

“…Two papers are on neuromuscular training programs (NMTs), training monotony (TM), and training strain (TS) in soccer players [ 2 , 3 ]; five articles provide innovative findings about testosterone and cortisol [ 4 , 5 ], gastrointestinal hormones [ 6 ], spirulina [ 7 ], and concentrations of erythroferrone (ERFE) [ 8 ]; another five papers analyze fitness and its association with other variables [ 7 , 9 , 10 , 11 , 12 ]; three papers examine body composition in elite female soccer players [ 2 ], adolescents [ 6 ], and obese women [ 7 ]; five articles examines the effects of high-intensity interval training (HIIT) [ 7 , 10 , 13 , 14 , 15 ]; one paper examines the acute effects of different levels of hypoxia on maximal strength, muscular endurance, and cognitive function [ 16 ]; another article evaluates the efficiency of using vibrating exercise equipment (VEE) compared with using sham-VEE in women with CLBP (chronic low-back pain) [ 17 ]; one article compares the effects of different exercise modes on autonomic modulation in patients with T2D (type 2 diabetes mellitus) [ 14 ]; and another paper analyzes the changes in ABB (acid–base balance) in the capillaries of kickboxers [ 18 ]. Other studies evaluate: the effects of resistance training on oxidative stress and muscle damage in spinal cord-injured rats [ 19 ]; the effects of muscle training on core muscle performance in rhythmic gymnasts [ 20 ]; the physiological profiles of road cyclist in different age categories [ 21 ]; changes in body composition during the COVID-19 [ 22 ]; a mathematical model capable of predicting 2000 m rowing performance using a maximum-effort 100 m indoor rowing ergometer [ 23 ]; the effects of ibuprofen on performance and oxidative stress [ 24 ]; the associations of vitamin D levels with various motor performance tests [ 12 ]; the level of knowledge on FM (Fibromyalgia) [ 25 ]; and the ability of a specific BIVA (bioelectrical impedance vector analysis) to identify changes in fat mass after a 16-week lifestyle program in former athletes [ ...…”