Effect of physical training on parathyroid hormone and bone turnover marker profile in relation to vitamin D supplementation in soccer players.

The aim of the study was to assess the impact of vitamin D supplementation and regular physical activity on 25-hydroxyvitamin D [25(OH)D], parathyroid hormone (PTH) and bone turnover marker concentrations in healthy male athletes. Twenty-five youth soccer players were divided into groups: non-supplemented (GN) and supplemented (GS) with a vitamin D dose of 20 000 IU twice a week for 8 weeks. The study was conducted during an 8-week preseason period, from mid-January to mid-March. At baseline (T1) and at the end of this period (T2), the serum concentrations of 25(OH)D, (PTH), osteocalcin (OC) and ß-isomerized C-terminal telopeptide of type I collagen (ß-CTx) were measured. At T2, 25(OH)D increased by 70% in GS (p = 0.004) and by 6% in GN (p > 0.05). Significant differences between GS and GN groups were observed throughout the study in the group-by-time interaction and changes of 25(OH)D (p = 0.002; η 2 p = 0.36) and OC (p = 0.008; η 2 p = 0.26). Increased OC (ES = 0.74; moderate) and ß-CTx (ES = 1.31, large) in GN athletes who had an optimal baseline vitamin D level (GO) were observed. In GN, at T2, ß-CTx positively correlated with PTH and OC (p = 0.007 and p = 0.002). In GS, ß-CTx positively correlated with OC at both time points (T1, p = 0.027 and T2, p = 0.037). A negative correlation between 25(OH)D and PTH was observed at T2 (p = 0.018). The obtained results suggest that the 20 000 IU vitamin D3 dose applied twice a week for 8 weeks is effective for vitamin D compensation and sufficient to maintain the correct PTH concentration, as revealed by changes in the bone marker concentrations. In conclusion, the results suggest that the applied vitamin D supplementation dose in athletes leads to intensive bone remodelling and has protective effects on bone under intensive physical effort.

Changes of physical match performance after the COVID-19 lockdown in professional soccer players according to their playing position.

The aim of this study was to evaluate the impact of the pandemic lockdown, which included training cessation and home-based training, on physical performance in professional soccer players from the Polish Ekstraklasa according to their playing position. The research was based on 3137 players' individual match performance observations during the 2019/2020 season divided into before (26 matchdays) and after (11 matchdays) lockdown periods. The data were collected using the computerised multiple-camera optical tracking system TRACAB (ChryronHego VID, New York, NY) with a sampling frequency of 25 Hz. Independently of playing position, a significant (p < 0.001) reduction in season resumption metrics of total distance (-0.9%), jogging (-1.6%), running (-3.4%) and high-speed running (-2.5%), with a contemporaneous increase in walking distance (1.4%), was noted in relation to pre-lockdown performance. A reduction in high-speed running was observed in central defenders (p < 0.05), central midfielders (p < 0.01) and forwards (p < 0.05). No significant decrease in sprinting or maximal running velocity was observed. The COVID-19 lockdown negatively influenced the physical performance in professional soccer players.

Gender differences in the association between physical activity and obesity in adults with vision and hearing losses.

BACKGROUND: Physical inactivity is strongly associated with obesity, which in turn is a major risk factor for many non-communicable diseases. We examined associations between physical inactivity and obesity in Spanish adults with vision and hearing difficulties and explored differences between men and women. METHODS: Data from the Spanish National Health Survey 2017 were analyzed [n = 23 089 adults (15-103 years, mean age 53.4 ± 18.9 years, 45.9% men)]. Participants self-reported difficulties in seeing and hearing. Physical inactivity (exposure) was evaluated with the International Physical Activity Questionnaire Short Form. Obesity (outcome) was defined as body mass index ≥30 kg m-2 based on self-reported weight and height. The association between physical inactivity and obesity was assessed with multivariable logistic regression in people with difficulties seeing and hearing, adjusting for significant covariates. RESULTS: Multivariable logistic regression analyses showed that the association between physical inactivity and obesity was stronger in those with difficulty hearing (OR 1.778, 95% CI 1.215-2.602) compared with difficulty seeing (OR 1.375, 95% CI 1.076-1.756). Gender-stratified analyses showed significant association between physical inactivity and obesity in men who reported difficulty hearing (OR 2.319, 95% CI 1.441-3.735) and difficulty seeing (OR 1.556, 95% CI 1.079-2.244), but not in women. CONCLUSIONS: A significant association between physical inactivity and obesity was observed in Spanish men with vision and hearing difficulties. Physical activity has an important role in the prevention of obesity in men with seeing and hearing difficulties. Active steps should be taken to encourage physical activity to reduce the risk of obesity in people with sensory impairments.

Comparison of physical activity levels in Spanish adults with chronic conditions before and during COVID-19 quarantine.

BACKGROUND: This is the first study analyzing levels of physical activity in a sample of quarantined adults with chronic conditions. The aim of this study was to compare moderate- and vigorous-intensity physical activity levels in Spanish adults with chronic conditions before and during coronavirus disease 2019 (COVID-19) quarantine. METHODS: A cross-sectional online survey was administered during the COVID-19 quarantine in Spain. A total of 163 participants with chronic conditions (113 females and 47 males; age range 18-64 years) completed the survey. A total of 26 chronic conditions were included. Participants self-reported average minutes/day of moderate and vigorous physical activity before and during quarantine. Differences in moderate- and vigorous-intensity physical activity levels before and during COVID-19 quarantine (overall, by gender, by age, by number of chronic conditions and by each chronic condition) were assessed by Wilcoxon-signed rank test. RESULTS: During COVID-19 quarantine, there was a significant decrease of moderate-intensity physical activity in Spanish people with chronic conditions (in both males and females, in those aged 18-24, 25-34, 35-44 and 55-64 years, in those with multimorbidity, in those with one/two chronic condition/s, and in those diagnosed with asthma/hypercholesterolaemia/chronic skin disease/haemorrhoids). Also, there was a significant decrease of vigorous-intensity physical activity in Spanish males with chronic conditions and in those with multimorbidity. CONCLUSIONS: These results should be considered to develop effective strategies of physical activity promotion targeting these specific groups when new quarantine or restriction measures are implemented, in order to avoid new significant decreases of physical activity in these vulnerable populations.

Vitamin D and Stress Fractures in Sport: Preventive and Therapeutic Measures-A Narrative Review.

There are numerous risk factors for stress fractures that have been identified in literature. Among different risk factors, a prolonged lack of vitamin D (25(OH)D) can lead to stress fractures in athletes since 25(OH)D insufficiency is associated with an increased incidence of a fracture. A 25(OH)D value of <75.8 nmol/L is a risk factor for a stress fracture. 25(OH)D deficiency is, however, only one of several potential risk factors. Well-documented risk factors for a stress fracture include female sex, white ethnicity, older age, taller stature, lower aerobic fitness, prior physical inactivity, greater amounts of current physical training, thinner bones, 25(OH)D deficiency, iron deficiency, menstrual disturbances, and inadequate intake of 25(OH)D and/or calcium. Stress fractures are not uncommon in athletes and affect around 20% of all competitors. Most athletes with a stress fracture are under 25 years of age. Stress fractures can affect every sporty person, from weekend athletes to top athletes. Stress fractures are common in certain sports disciplines such as basketball, baseball, athletics, rowing, soccer, aerobics, and classical ballet. The lower extremity is increasingly affected for stress fractures with the locations of the tibia, metatarsalia and pelvis. Regarding prevention and therapy, 25(OH)D seems to play an important role. Athletes should have an evaluation of 25(OH)D -dependent calcium homeostasis based on laboratory tests of 25-OH-D3, calcium, creatinine, and parathyroid hormone. In case of a deficiency of 25(OH)D, normal blood levels of ≥30 ng/mL may be restored by optimizing the athlete's lifestyle and, if appropriate, an oral substitution of 25(OH)D. Very recent studies suggested that the prevalence of stress fractures decreased when athletes are supplemented daily with 800 IU 25(OH)D and 2000 mg calcium. Recommendations of daily 25(OH)D intake may go up to 2000 IU of 25(OH)D per day.

Comparison of physical activity levels in Spanish people with diabetes with and without cataracts.

BACKGROUND: The objective was to compare levels of physical activity (PA) in a large sample of Spanish people with diabetes with and without cataracts. To our knowledge, this is the first study comparing PA levels in people with diabetes with and without cataracts in a large representative sample. METHODS: Cross-sectional data from the Spanish National Health Survey 2017 were analyzed (n = 1014 people with diabetes; 43.1% females; age range 15-69 years; mean age 58.4 ± 9.2 years). International Physical Activity Questionnaire (IPAQ) short form was used to measure PA. Total MET-min week-1 of PA were calculated and participants were divided into two categories according to American Diabetes Association PA guidelines: (i) <600 MET-min week-1. (ii) At least 600 MET-min week-1. Diabetes and cataracts were self-reported in response to the questions 'Have you ever been diagnosed with diabetes/cataracts?' Participants also reported other variables including age, gender, marital status, living as a couple, education, smoking, alcohol consumption and obesity. Statistical analysis was performed with SPSS 23.0. RESULTS: The overall prevalence of cataract was 14.0% and the overall prevalence of people doing <600 MET-min week-1 of PA was 35.4%. The prevalence of cataract was significantly lower in those doing more PA (12.1% vs. 17.5%; P = 0.016). Those without cataracts were significantly more active than those with cataracts (1846.8 vs. 1289.4 MET-min week-1; P = 0.001). The adherence to American Diabetes Association PA guidelines was significantly higher in those without cataracts (66.1% vs. 55.6%; P = 0.016). CONCLUSIONS: Interventions to promote PA targeting people with both diabetes and cataracts are warranted.

Leptin and Leptin Receptor Genes Are Associated With Obesity-Related Traits Changes in Response to Aerobic Training Program.

Leonska-Duniec, A, Jastrzebski, Z, Jazdzewska, A, Krzysztof, F, and Cieszczyk, P. Leptin and leptin receptor genes are associated with obesity-related traits changes in response to aerobic training program. J Strength Cond Res 32(4): 1036-1044, 2018-Leptin (LEP) and leptin receptor (LEPR) genes have been studied for their potential association with development of human obesity and its related complications. Therefore, we have decided to check whether selected body mass, body composition, and metabolic variables observed in physically active participants will be modulated by the polymorphisms. The genotype distribution was examined in a group of 201 women measured for chosen traits before and after the completion of a 12-week aerobic training program. Our results revealed a significant interaction between training and LEP genotype for glucose level. A training-related decrease in plasma glucose concentration in the LEP AG heterozygotes differed significantly from the change in the homozygotes. The polymorphism was also associated with fat-free mass (FFM), total body water (TBW), total cholesterol, triglycerides, and low-density lipoprotein cholesterol (LDL-C) levels. Another finding was a significant interaction between training and LEPR for LDL-C level. As opposed to AG and GG, AA homozygotes demonstrated a training-related decrease in LDL-C level. Our findings also showed that the LEPR G allele is connected with obesity-related traits. The participants with the GG genotype had higher body mass, body mass index (BMI), FFM, and TBW during the entire study period. This study provides evidence that polymorphisms in the LEP and LEPR genes are associated with the magnitude of the effects of regular physical activity on glucose and LDL-C levels, respectively. In addition, we found the association of the G allele of the LEPR polymorphism with body mass and BMI.

Glomerular Filtration Rate Is Unchanged by Ultramarathon.

Wolyniec, W, Ratkowski, W, Kasprowicz, K, Jastrzebski, Z, Malgorzewicz, S, Witek, K, Grzywacz, T, Zmijewski, P, and Renke, M. Glomerular filtration rate is unchanged by ultramarathon. J Strength Cond Res 32(11): 3207-3215, 2018-Acute kidney injury (AKI) is reported as a common complication of marathon and ultramarathon running. In previous studies, AKI was diagnosed on the basis of the creatinine level in serum and estimated glomerular filtration rate (eGFR). In this study, we calculated eGFR and also measured creatinine clearance after every 25 km of a 100-km run. Twenty healthy, amateur runners (males, mean age 40.75 ± 7.15 years, mean body mass 76.87 ± 8.39 kg) took part in a 100-km run on a track. Blood and urine were collected before the run, after every 25 km, and 12 hours after the run. Seventeen runners completed the study. There was increase in creatinine, urea, and uric acid observed after 100 km (p < 0.05). The mean increase in creatinine was 0.21 mg·dl (24.53%). Five runners fulfilled the AKI network criteria of AKI. The eGFR according to the modification of diet in renal disease, chronic kidney disease epidemiology collaboration, and Cockcroft-Gault formulas was significantly decreased after the run (p ≤ 0.05). Otherwise, creatinine clearance calculated from creatinine level in both serum and urine remained stable. In contrast to the majority of previous studies, we did not observe any decrease in the kidney function during an ultramarathon. In this study, the creatinine clearance, which is the best routine laboratory method to determine GFR was used. There is no evidence that long running is harmful for kidney.

ADIPOQ polymorphisms are associated with changes in obesity-related traits in response to aerobic training programme in women.

Among genetic variants of the ADIPOQ gene +276 G>T (rs1501299) and -11377 G>C (rs266729) are the most frequently investigated polymorphisms which were described in the context of genetic conditioning for a predisposition to obesity. However, the information of polymorphisms' potential modifying effect on obesity-related traits achieved through training procedures are still unknown. DNA was extracted from buccal cells donated by the 201 participants and genotyping was carried out using real-time PCR. The genotype distribution was examined in a group of women measured for chosen traits before and after the completion of a 12-week training programme. Our results suggest that the ADIPOQ genotypes analyzed individually or in combination can modulate training-induced body mass measurements changes: after the training programme, carriers of rs1501299 T allele and rs266729 C allele were characterized by a greater reduction in fat mass percentage (FM), fat mass, and body mass. Moreover, the ADIPOQ polymorphisms were associated with changes in lipid profile in response to training. Additionally, we showed three main effects of genotypes for the FM, LDL-C (rs266729), and TBW (rs1501299). Our study indicate that the both polymorphisms are associated with changes in obesity-related traits in response to 12-week aerobic training programme in Caucasian women. From this evidence, it could be concluded that rs1501299 G and rs266728 G variants may be considered as disadvantageous factor in the context of training-induced effects on body mass traits.

Individual Responsiveness to Exercise-Induced Fat Loss and Improvement of Metabolic Profile in Young Women is Associated with Polymorphisms of Adrenergic Receptor Genes.

The effectiveness of physical exercise on fat loss and improvement of aerobic capacity varies considerably between individuals. A strong linkage exists between common allelic variants of the adrenergic receptor genes and weight gain, as well as changes in body composition. Therefore we aimed to check if body composition and metabolic variables were modulated by the ADRB2 (Gly16Arg and Glu27Gln), ADRB3 (Trp64Arg) and ADRA2A (rs553668 G/A) gene polymorphisms in 163 Polish sedentary women (age 19-24; body mass index (BMI) 21.7 ± 0.2 kg·m-2) involved in a 12-week aerobic training program. Only 74.8% of participants lost fat mass. On average, participants lost 5.8 (10.4)% of their relative fat mass with training (range: +28.3 to -63.6%). The improvement of VO2max was significantly greater in women who could lose their fat mass compared to women who were unsuccessful in fat loss (4.5 (5.6)% vs. 1.5 (3.8)%; p = 0.0045). The carriers of a low number (0-3) of obesity-related risk alleles (ADRB2 Gly16, ADRB2 Glu27, ADRA2A rs553668 G) were more successful in fat mass loss compared to the carriers of a high number (5-6) of risk alleles (7.7 (9.8) vs 4.0 (9.4)%, p = 0.0362). The presented results support the assumption that variation within adrenergic receptor genes contributes to interindividual changes of body composition in response to physical exercise.

GSTP1 c.313A>G polymorphism in Russian and Polish athletes.

The GSTP1 gene encodes glutathione S-transferase P1, which is a member of the glutathione S-transferases (GSTs), a family of enzymes playing an important role in detoxification and in the antioxidant defense system. There is some evidence indicating that GSTP1 c.313A>G polymorphism may be beneficial for exercise performance. Therefore, we decided to verify the association between the frequency of GSTP1 c.313A>G variants, physical performance, and athletes' status in two cohorts: in a group of Russian athletes (n = 507) and in an independent population of Polish athletes (n = 510) in a replication study. The initial association study conducted with the Russian athletes revealed that the frequency of the minor G allele was significantly higher in all athletes than in controls; that was confirmed in the replication study of Polish athletes. In the combined cohort, the differences between athletes (n = 1017) and controls (n = 1246) were even more pronounced (32.7 vs 25.0%, P < 0.0001). Our findings emphasize that the G allele of the GSTP1 gene c.313A>G single nucleotide polymorphism is associated with improved endurance performance. These observations could support the hypothesis that the GSTP1 G allele may improve exercise performance by better elimination of exercise-induced ROS.

Expression analysis of selected classes of circulating exosomal miRNAs in soccer players as an indicator of adaptation to physical activity.

Recently studies have shown that, depending on the type of training and its duration, the expression levels of selected circulating myomiRNAs (c-miR-27a,b, c-miR-29a,b,c, c-miR-133a) differ and correlate with the physiological indicators of adaptation to physical activity. To analyse the expression of selected classes of miRNAs in soccer players during different periods of their training cycle. The study involved 22 soccer players aged 17-18 years. The multi-stage 20-m shuttle run test was used to estimate VO2 max among the soccer players. Samples serum were collected at baseline (time point I), after one week (time point II), and after 2 months of training (time point III). The analysis of the relative quantification (RQ) level of three exosomal myomiRNAs, c-miRNA-27b, c-miR-29a, and c-miR-133, was performed by quantitative polymerase chain reaction (qPCR) at three time points - before the training, after 1 week of training and after the completion of two months of competition season training. The expression analysis showed low expression levels (according to references) of all evaluated myomiRNAs before the training cycle. Analysis performed after a week of the training cycle and after completion of the entire training cycle showed elevated expression of all tested myomiRNAs. Statistical analysis revealed significant differences between the first and the second time point in soccer players for c-miR-27b and c-miR-29a; between the first and the third time point for c-miR-27b and c-miR-29a; and between the second and the third time point for c-miR-27b. Statistical analysis showed a positive correlation between the levels of c-miR-29a and VO2 max. Two months of training affected the expression of c-miR-27b and miR-29a in soccer players. The increased expression of c-miR-27b and c-miR-29 with training could indicate their probable role in the adaptation process that takes place in the muscular system. Possibly, the expression of c-miR-29a will be found to be involved in cardiorespiratory fitness in future research.

Effect of Vitamin D Supplementation on Training Adaptation in Well-Trained Soccer Players.

Jastrzebska, M, Kaczmarczyk, M, and Jastrzebski, Z. Effect of vitamin D supplementation on training adaptation in well-trained soccer players. J Strength Cond Res 30(9): 2648-2655, 2016-There is growing body of evidence implying that vitamin D may be associated with athletic performance, however, studies examining the effects of vitamin D on athletic performance are inconsistent. Moreover, very little literature exists about the vitamin D and training efficiency or adaptation, especially in high-level, well-trained athletes. The purpose of the current study was to investigate the effect of vitamin D supplementation on training adaptation in well-trained football players. The subjects were divided into 2 groups: the placebo group (PG) and the experimental group (SG, supplemented with vitamin D, 5,000 IU per day). Both groups were subjected to High Intensity Interval Training Program. The selection to the groups was based on peak power results attained before the experiment and position on the field. Blood samples for vitamin D level were taken from the players. In addition, total work, 5, 10, 20, and 30 m running speed, squat jump, and countermovement jump height were determined. There were no significant differences between SG and PG groups for any power-related characteristics at baseline. All power-related variables, except the 30 m sprint running time, improved significantly in response to interval training. However, the mean change scores (the differences between posttraining and pretraining values) did not differ significantly between SG and PG groups. In conclusion, an 8-week vitamin D supplementation in highly trained football players was not beneficial in terms of response to High Intensity Interval Training. Given the current level of evidence, the recommendation to use vitamin D supplements in all athletes to improve performance or training gains would be premature. To avoid a seasonal decrease in 25(OH)D level or to obtain optimal vitamin D levels, the combination of higher dietary intake and vitamin D supplementation may be necessary.

EPAS1 gene variants are associated with sprint/power athletic performance in two cohorts of European athletes.

BACKGROUND: The endothelial PAS domain protein 1 (EPAS1) activates genes that are involved in erythropoiesis and angiogenesis, thus favoring a better delivery of oxygen to the tissues and is a plausible candidate to influence athletic performance. Using innovative statistical methods we compared genotype distributions and interactions of EPAS1 SNPs rs1867785, rs11689011, rs895436, rs4035887 and rs1867782 between sprint/power athletes (n=338), endurance athletes (n=254), and controls (603) in Polish and Russian samples. We also examined the association between these SNPs and the athletes' competition level ('elite' and 'sub-elite' level). Genotyping was performed by either Real-Time PCR or by Single-Base Extension (SBE) method. RESULTS: In the pooled cohort of Polish and Russian athletes, 1) rs1867785 was associated with sprint/power athletic status; the AA genotype in rs1867785 was underrepresented in the sprint/power athletes, 2) rs11689011 was also associated with sprint/power athletic status; the TT genotype in rs11689011 was underrepresented sprint/power athletes, and 3) the interaction between rs1867785, rs11689011, and rs4035887 was associated with sprint/power athletic performance; the combinations of the AA genotype in rs4035887 with either the AG or GG genotypes in rs1867785, or with the CT or CC genotypes in rs11689011, were underrepresented in two cohorts of sprint/power athletes. CONCLUSIONS: Based on the unique statistical model rs1867785/rs11689011 are strong predictors of sprint/power athletic status, and the interaction between rs1867785, rs11689011, and rs4035887 might contribute to success in sprint/power athletic performance.

AGTR2 gene polymorphism is associated with muscle fibre composition, athletic status and aerobic performance.

Muscle fibre type is a heritable trait and can partly predict athletic success. It has been proposed that polymorphisms of genes involved in the regulation of muscle fibre characteristics may predispose the muscle precursor cells of a given individual to be predominantly fast or slow. In the present study, we examined the association between 15 candidate gene polymorphisms and muscle fibre type composition of the vastus lateralis muscle in 55 physically active, healthy men. We found that rs11091046 C allele carriers of the angiotensin II type 2 receptor gene (AGTR2; involved in skeletal muscle development, metabolism and circulatory homeostasis) had a significantly higher percentage of slow-twitch fibres than A allele carriers [54.2 (11.1) versus 45.2 (10.2)%; P = 0.003]. These data indicate that 15.2% of the variation in muscle fibre composition of the vastus lateralis muscle can be explained by the AGTR2 genotype. Next, we investigated the frequencies of the AGTR2 alleles in 2178 Caucasian athletes and 1220 control subjects. The frequency of the AGTR2 C allele was significantly higher in male and female endurance athletes compared with power athletes (males, 62.7 versus 51.7%, P = 0.0038; females, 56.6 versus 48.1%, P = 0.0169) and control subjects (males, 62.7 versus 51.0%, P = 0.0006; elite female athletes, 65.1 versus 55.2%, P = 0.0488). Furthermore, the frequency of the AGTR2 A allele was significantly over-represented in female power athletes (51.9%) in comparison to control subjects (44.8%, P = 0.0069). We also found that relative maximal oxygen consumption was significantly greater in male endurance athletes with the AGTR2 C allele compared with AGTR2 A allele carriers [n = 28; 62.3 (4.4) versus 57.4 (6.0) ml min(-1) kg(-1); P = 0.0197]. Taken together, these results demonstrate that the AGTR2 gene C allele is associated with an increased proportion of slow-twitch muscle fibres, endurance athlete status and aerobic performance, while the A allele is associated with a higher percentage of fast-twitch fibres and power-oriented disciplines.

Effects of applied training loads on the aerobic capacity of young soccer players during a soccer season.

The aim of this study was to examine the effects of applied training loads on the aerobic capacity, speed, power, and speed endurance of young soccer players during 1 soccer season. The participants in the study were 19 young male soccer players (age: 16.61 ± 0.31 years; weight: 64.28 ± 6.42 kg; height: 176.58 ± 5.98 cm). The players completed 150 training sessions and 54 games over the course of 1 soccer season. The training intensity was divided into 4 categories: (a) aerobic performance (61% of the total training duration), (b) mixed aerobic-anaerobic performance (34%), (c) anaerobic lactate performance (3%), and (d) anaerobic nonlactate performance (2%). No significant changes in the V[Combining Dot Above]O2max were observed throughout the season. The players' power level and speed endurance increased significantly with the coincident decrements in their 5-m sprint time. The applied training loads, including 1 high-intensity training session of small-sided games performed during a competitive season, did not significantly change the aerobic capacity of the young soccer players. However, the participants did maintain their V[Combining Dot Above]O2max at the elite level. The first squad players (FSPs) reached the highest level of aerobic fitness in the middle of the season, whereas substitute players (SPs) at the end of the season. Moreover, the V[Combining Dot Above]O2max in FSP was significantly higher (p < 0.003) than in SP in the middle of the season.

Effects of 8-Week Online, Supervised High-Intensity Interval Training on the Parameters Related to the Anaerobic Threshold, Body Weight, and Body Composition during Pregnancy: A Randomized Controlled Trial.

We aimed to assess the effects of an 8-week, online high-intensity interval training (HIIT) program on the parameters related to the anaerobic threshold (AT), body weight, and body composition in pregnant women. A total of 69 Caucasian women with an uncomplicated singleton pregnancy (age: 31 ± 4 years; gestational age: 22 ± 5 weeks; mean ± standard deviation) were randomly allocated to either an 8-week HIIT program (HIIT group) or to a comparative 8-week educational program (EDU group). Our most important finding was that even with the 8-week progression of pregnancy and physiological weight gain, the HIIT group maintained the same level of parameters related to AT: volume of oxygen at the AT (VO2/AT), percentage of maximal oxygen uptake at the AT (%VO2max/AT), and heart rate at the AT (HR/AT). In contrast, in the EDU group we observed a substantial deterioration of parameters related to the AT. The HIIT intervention substantially reduced the fat mass percentage (median: 30 to 28%; p < 0.01) and improved the total fat-free mass percentage (median: 70% to 72%; p < 0.01). In the EDU group, the body composition did not change significantly. An online, supervised HIIT program may be used to prevent the pregnancy-related risk of excessive weight gain and reduction in exercise capacity without yielding adverse obstetric or neonatal outcomes.

Correlation between the Positive Effect of Vitamin D Supplementation and Physical Performance in Young Male Soccer Players.

The aim of this study was to determine whether supplementation with vitamin D during eight weeks of high-intensity training influences muscle power and aerobic performance in young soccer players. A total of 25 athletes were divided into two groups: the supplemented group (GS; n = 12; vitamin D 20,000 IU, twice a week) and the non-supplemented group (GN; n = 13). A set of measurements, including sprint tests, explosive power test, maximal oxygen uptake (VO2max), and serum 25(OH)D concentration, were obtained before (T1) and after (T2) the intervention. A significant group x time interaction was found in the 25(OH)D serum levels (p = 0.002; ES = 0.36, large). A significant improvement in VO2max was found in the TG (p = 0.0004) and the GS (p = 0.031). Moreover, a positive correlation between 25(OH)D and VO2max (R = 0.4192, p = 0.0024) was calculated. The explosive power tests revealed insignificant time interactions in the average 10-jump height and average 10-jump power (p = 0.07, ES = 0.13; p = 0.10, ES = 0.11, respectively). A statistically insignificant trend was observed only in the group-by-time interaction for the sprint of 10 m (p = 0.05; ES = 0.15, large). The present study provides evidence that vitamin D supplementation has a positive but trivial impact on the explosive power and locomotor skills of young soccer players, but could significantly affect their aerobic performance.

Effect of Vitamin D3 Supplementation on Interleukin 6 and C-Reactive Protein Profile in Athletes.

Vitamin D3 has a preventive, anti-inflammatory effect. However, there are still few studies linking the effects of athlete training to vitamin D3 supplementation and the immune response. The study evaluated the impact of vitamin D3 supplementation on interleukin 6 (IL-6) release during physical exercise in relation to C-reactive protein (CRP) levels in healthy male athletes. Twenty-five soccer players were divided into two groups-with (GS) and without (GN) vitamin D3 supplementation in a dose of 20,000 IU twice a week for 8 wk (about 6,000 IU/d). At the baseline (T1) and at the end (T2) of the training cycle serum concentrations of 25-hydroxyvitamin D [25(OH)D], IL-6 and CRP were measured. In the GS group, we observed a significant increase in 25(OH)D concentration (p=0.004), and non-significantly increased levels (p>0.05) of IL-6 and CRP. At the baseline, CRP in the supplemented athletes who had suboptimal vitamin D3 concentration in T1 (GSO) was significantly higher than in those with an optimal baseline vitamin D3 level (GO) (p=0.028). However, in GO in T2, a non-significant trend of negative correlation (p=0.055) between 25(OH)D concentration and IL-6 level was found. In the total study group (TG), a statistically significant (p=0.021) negative correlation in T1 was observed between 25(OH)D and CRP. However, our results do not support the immune-modulatory effect of vitamin D3 supplementation in a dose of 6,000 IU/d in athletes, in relation to IL-6 production and its subsequent stimulatory effect on CRP releasing.

[Vitamin D Deficiency in Sports]. / Vitamin-D-Mangel im Sport.

Vitamin D Deficiency in Sports Abstract. A deficiency in vitamin D is very common in the general population as well as in athletes. The aim of this overview is to assess the level of knowledge about the importance of vitamin D for athletes. A deficiency in vitamin D is present in up to 90 % of athletes. Risk groups are young athletes, female athletes, athletes with a limitation such as paraplegia, vegetarians, athletes with a resorption disorder such as celiac disease, athletes training and competing indoors (e.g. ice hockey, basketball, boxing, rhythmic gymnastics), and older athletes. Dark skin pigmentation, the use of sunscreen, the time of day of the training (early morning, late evening) and the geographical location influence the risk for a deficiency in vitamin D. Exposure to the sun and a balanced diet are often not enough to prevent a vitamin D deficiency.