Effects of Vitamin D Supplementation on Haematological Values and Muscle Recovery in Elite Male Traditional Rowers

Abstract

Introduction: Deficient levels of 25-hydroxyvitamin D (25(OH)D) (<30 ng/mL) may compromise health and athletic performance. Supplementation with oral vitamin D can favor the state of iron metabolism, and testosterone and cortisol as an indicator of muscle recovery of the athlete with a deficiency. The main aim of this study was to evaluate the influence of eight weeks of supplementation with 3000 IU/day of vitamin D on the hematological and iron metabolism profile, as well as on the analytical values of testosterone and cortisol on elite male traditional rowers. The secondary aim was to examine if serum 25(OH)D is a predictor of testosterone and cortisol levels. Material and Methods: Thirty-six elite male rowers (27 ± 6 years) were assigned to one of the two groups randomly: 1) Control group (CG, n = 18, height: 181.05 ± 3.39 cm and body mass: 77.02 ± 7.55 kg), 2) Group treated with 3,000 IU of vitamin D3/day (VD3G, s = 18, height: 179.70 ± 9.07 cm and body mass: 76.19 ± 10.07 kg). The rowers were subjected to blood tests at the beginning of the study (T1) and after eight weeks of treatment (T2), for the analysis of hematological and hormonal values. Repeated-measures ANOVA with group factor (GC and GVD3) were used to examine if the interaction of the different values was the same or different between the groups throughout the study (time × group) after vitamin D3 treatment. To analyze if 25(OH)D was a good predictor of testosterone, cortisol, and testosterone/cortisol ratio a stepwise regression model was performed. Results: Statistically significant and different increases were observed in the group-by-time interaction of 25(OH)D in VD3G in respect to CG during the study (p < 0.001; VD3G (T1: 26.24 ± 8.18 ng/mL vs. T2: 48.12 ± 10.88 ng/mL) vs CG (T1: 30.76 ± 6.95 ng/mL vs. T2: 35.14 ± 7.96 ng/mL). Likewise, significant differences between groups were observed throughout the study in the group-by-time interaction and changes of hemoglobin (GC: −2.89 ± 2.29% vs. VD3G: 0.71 ± 1.91%; p = 0.009), hematocrit (CG: −1.57 ± 2.49% vs. VD3G: 1.16 ± 1.81%; p = 0.019) and transferrin (CG: 0.67 ± 4.88% vs. VD3G: 6.51 ± 4.36%; p = 0.007). However, no differences between groups were observed in the group-by-time interaction of the hormonal parameters (p > 0.05). Regression multivariate analysis showed that cortisol and testosterone levels were associated with 25(OH)D levels (p < 0.05). Conclusion: Oral supplementation with 3000 IU/day of vitamin D3 during eight weeks showed to be sufficient to prevent a decline in hematological levels of hemoglobin and hematocrit, and improve transferrin of 25(OH)D levels. However, although it was not sufficient to enhance muscle recovery observed by testosterone and cortisol responses, it was observed that serum 25(OH)D levels could be a predictor of anabolic and catabolic hormones.

Long-Term Effect of Combination of Creatine Monohydrate Plus β-Hydroxy β-Methylbutyrate (HMB) on Exercise-Induced Muscle Damage and Anabolic/Catabolic Hormones in Elite Male Endurance Athletes

“…The CrM and HMB supplementation dosages were selected in accordance with a supplementation standard for athletic performance [34,35] and elite rowers [41]. All participants attended the laboratory at 8:30 a.m. for blood collection at two different times during the intervention period: (1) at baseline (T1) and (2) post-treatment after 10 weeks of supplementation (T2).…”

“…Elite sports are immensely demanding at the physical and psychological level, and an adequate balance between training load and recovery is needed to achieve maximum performance [1]. Prolonged and excessive training and/or insufficient recovery can result in nonfunctional overreaching or an overtraining syndrome due to increased stress and fatigue and, consequently, impairment or stagnation of performance [1][2][3]. Therefore, recovery processes are determinants in sport performance [4].…”

Influence of Sunlight and Oral D3 Supplementation on Serum 25(OH)D Concentration and Exercise Performance in Elite Soccer Players

“…Vitamin D insufficiency seems to also be a prominent problem among athletes [2,6,7]. It has been estimated that during the winter season, almost 60% of outdoor athletes and 64% of indoor athletes have a level of 25(OH)D <30 ng/mL, which indicates insufficiency of vitamin D [11][12][13][14][15]. Athletes who live at latitudes of 35 • degrees or below train outdoors and use sunscreen during summer and cover-up from cold during autumn, winter and spring are vulnerable to serum 25-hydroxyvitamin D (25(OH)D) insufficiency [16,17].…”

Contributions of Anthropometric and Strength Determinants to Estimate 2000 m Ergometer Performance in Traditional Rowing

“…and other regions like Saudi Arabia [13]. Traditional rowing studies has increased in the field of sports profile [14], championships performance [13], supplementation [15], physiological factors [4] and different training characteristics and methodologies [4,16].…”