Effect of Pre-exercise Sodium Citrate Ingestion on Repeated Sprint Performance in Soccer Players.

ABSTRACT: Kuru, D, Aktitiz, S, Atakan, MM, Köse, MG, Turnagöl, HH, and Kosar, SN. Effect of pre-exercise sodium citrate ingestion on repeated sprint performance in soccer players. J Strength Cond Res 38(3): 556-562, 2024-This study aimed to test the hypothesis that sodium citrate (CIT) administered 180 minutes before exercise improves repeated sprint performance in athletes within a field-based setting. Twenty male soccer players (mean ± SD : age = 20.9 ± 2.3 years; body mass [BM] = 73.8 ± 5.9 kg) performed a running-based anaerobic sprint test (RAST) with 0.5 g·kg -1 BM of CIT or with placebo (PLC; NaCl) ingestion 180 minutes before exercise in a randomized, crossover, and double-blind design, with at least 6 days between the trials. Blood samples were collected before exercise and at first, third, fifth, and seventh minutes after exercise to analyze blood pH, bicarbonate, and lactate levels. Gastrointestinal symptoms were also monitored at 30-minute intervals for 180 minutes after CIT and PLC ingestion. Pre-exercise blood pH (CIT = 7.49 ± 0.03 vs. PLC = 7.41 ± 0.02) and bicarbonate (CIT = 30.57 ± 1.33 vs. PLC = 25.25 ± 1.52) increased with CIT compared with PLC ( p < 0.001). Blood pH, bicarbonate, and lactate at the first, third, fifth, and seventh minutes after RAST with CIT were higher than PLC ( p < 0.05), except for lactate at first minute ( p > 0.05). Compared with PLC, CIT ingestion significantly improved minimum power output ( p = 0.024) and percentage decrement score ( p = 0.023). Gastrointestinal symptoms were significantly higher after CIT ingestion vs. PLC at 30th ( p = 0.003) and 60th minutes ( p = 0.010). However, there were no significant differences at 90th, 120th, 150th, or 180th minutes ( p > 0.05). The ingestion of 0.5 g·kg -1 BM of CIT 180 minutes before exercise is an effective ergogenic aid for improving repeated sprint ability as evidenced by improvements in minimum power output and percentage decrement score.

Energy balance and energy availability of female basketball players during the preparation period.

OBJECTIVE: To determine the level of energy balance and energy availability (EA) in female basketball players during the preparation period. METHODS: Fifteen basketball players (age: 19.53 ± 1.3 years; height: 173.6 ± 8.95 cm; weight: 67.55 ± 14.34 kg; training experience: 9.6 ± 2.7 years) and 15 age and body mass index-matched controls (age: 19.53 ± 1.1 years; height: 169.4 ± 5.06 cm; weight: 63.10 ± 6.14 kg) participated in the study. Resting metabolic rate (RMR) and body composition were measured by the indirect calorimetric method and dual-energy x-ray absorptiometry, respectively. A 3-day food diary was used to determine macronutrients and energy intake while a 3-day physical activity log was used to determine energy expenditure. Independent Samples t-test was used for data analysis. RESULTS: The daily energy intake and expenditure of female basketball players were 2136.5 ± 594.9 kcal·day-1 and 2953.8 ± 614.5 kcal·day-1, respectively, indicating 817 ± 779 kcal·day-1 of negative energy balance. One hundred percent and 66.6% of the athletes failed to meet the carbohydrate and protein intake recommendations, respectively. EA of female basketball players was 33.04 ± 15.69 kcal·fat free mass-1·day-1 and the percentages of athletes who had negative energy balance, low EA, and reduced EA were 80%, 40%, and 46.7%, respectively. However, despite the low and decreased EA, the measured RMR to predicted RMR ratio (RMRratio) was 1.31 ± 0.17 and the body fat percentage (BF%) was 31.00 ± 5.21%. CONCLUSION: This study shows that female basketball players have a negative energy balance during the preparation period which can be partly explained by insufficient carbohydrate intake. Although most of the athletes experienced low or reduced EA during the preparation period, the physiologically normal RMRratio and relatively high BF% indicate that this is a transient situation. In this regard, strategies to prevent the development of low EA and negative energy balance during the preparation period will contribute to positive training adaptations throughout the competition period.

Interleukin-6, undercarboxylated osteocalcin, and brain-derived neurotrophic factor responses to single and repeated sessions of high-intensity interval exercise.

OBJECTIVES: The purpose of this study was to compare the effects of a single session of high-intensity interval exercise (HIIE) with 2 consecutive HIIEs, separated by 3 h of recovery, on plasma interleukin-6 (IL-6), undercarboxylated osteocalcin (ucOC), and brain-derived neurotrophic factor (BDNF) responses. METHODS: Twenty male recreational endurance athletes completed two HIIE trials in a randomized crossover design: a single session of HIIE on the single exercise day (HIIE-S) and two sessions of HIIE 3 h apart on the double exercise day (HIIE-D). The HIIE protocol consisted of 10 × 1 min cycling at 100 % of peak oxygen uptake, with 75 s of low-intensity cycling at 60 W. Blood samples were collected to analyze IL-6, ucOC, and BDNF levels before and immediately after HIIE on the HIIE-S and before and immediately after the second HIIE on the HIIE-D. RESULTS: Both HIIE interventions significantly increased (p < 0.001) plasma IL-6 (HIIE-S 33.90 % vs HIIE-D 31.04 %; p = 0.64), ucOC (HIIE-S 37.18 % vs HIIE-D 39.54 %; p = 0.85), and BDNF levels (HIIE-S 236.01 % vs HIIE-D 216.68 %; p = 0.69), with no group effect. CONCLUSIONS: Our results demonstrate that performing two consecutive HIIEs on the same day with a 3-h rest results in similar changes in plasma levels of IL-6, BDNF, and ucOC compared with a single session of HIIE.

Exercise and Metabolic Health: The Emerging Roles of Novel Exerkines.

Physical inactivity is a major cause of chronic diseases. It shortens the health span by lowering the age of the first chronic disease onset, which leads to decreased quality of life and increased mortality risk. On the other hand, physical exercise is considered a miracle cure in the primary prevention of at least 35 chronic diseases, including obesity, insulin resistance, and type 2 diabetes. However, despite many scientific attempts to unveil the health benefits conferred by regular exercise, the underlying molecular mechanisms driving such benefits are not fully explored. Recent research shows that exercise-induced bioactive molecules, named exerkines, might play a critical role in the regulation of metabolic homeostasis and thus prevent metabolic diseases. Here we summarize the current understanding of the health-promoting effects of exerkines secreted from skeletal muscle, adipose tissue, bone, and liver, including MOTS-c, BDNF, miR-1, 12,13-diHOME, irisin, SPX, OC, GDF15, and FGF21 on obesity, insulin resistance, and type 2 diabetes. Identifying the systemic health benefits of exerkines may open a new area for the discovery of new pharmacological strategies for the prevention and management of metabolic diseases.

Nutritional Considerations for Injury Prevention and Recovery in Combat Sports.

Sports participation is not without risk, and most athletes incur at least one injury throughout their careers. Combat sports are popular all around the world, and about one-third of their injuries result in more than 7 days of absence from competition or training. The most frequently injured body regions are the head and neck, followed by the upper and lower limbs, while the most common tissue types injured are superficial tissues and skin, followed by ligaments and joint capsules. Nutrition has significant implications for injury prevention and enhancement of the recovery process due to its effect on the overall physical and psychological well-being of the athlete and improving tissue healing. In particular, amino acid and protein intake, antioxidants, creatine, and omega-3 are given special attention due to their therapeutic roles in preventing muscle loss and anabolic resistance as well as promoting injury healing. The purpose of this review is to present the roles of various nutritional strategies in reducing the risk of injury and improving the treatment and rehabilitation process in combat sports. In this respect, nutritional considerations for muscle, joint, and bone injuries as well as sports-related concussions are presented. The injury risk associated with rapid weight loss is also discussed. Finally, preoperative nutrition and nutritional considerations for returning to a sport after rehabilitation are addressed.

A comparison of dietary acid load between team, endurance, and strength sports

ABSTRACT Purpose: Since the dietary acid load (PRAL) may affect the acid-base balance of the body, there is an increasing interest in its role in sports performance. Typical nutritional requirements of different sports, associated with its physiological demands, might be reflected in the acid load of their diet. Thus, the purpose of this study is to compare the dietary acid load between team, endurance, and strength athletes and to determine the associations between PRAL and hydration status. Methods: Fifty-one healthy recreational male athletes (age: 18-39 yrs) from team, endurance, and strength sports participated in the study. A 3-day food diary was recorded and dietary PRAL values (mEq/day) were calculated. Urine pH and specific gravity were measured. One-way ANOVA with Bonferroni post-hoc analysis and Pearson correlation coefficient (r) were used for data analysis. Results: PRAL in endurance athletes (25.34 mEq/day) was lower compared to team and strength athletes (46.12 and 46.47 mEq/day, respectively) (p= 0.023). Percentage of high PRAL diet (≥15 (mEq/day)) was highest in team sports (89.5%), followed by strength (83.3%) and endurance sports (60%). PRAL was not associated with hydration status. Conclusion: Typical nutritional requirements of sport disciplines are reflected in the PRAL, thus PRAL should be considered when preparing nutritional strategies to improve performance.

RESUMEN Objetivo: Dado que la carga ácida de la dieta (PRAL) puede afectar el equilibrio ácido-base del cuerpo, existe un interés creciente en su papel en el rendimiento deportivo. Los requerimientos nutricionales típicos de diferentes deportes, asociados con sus demandas fisiológicas, pueden reflejarse en la carga ácida de su dieta. Por lo tanto, el propósito de este estudio fue comparar la carga ácida de la dieta entre atletas de equipo, de resistencia y de fuerza, y determinar las asociaciones entre PRAL y el estado de hidratación. Métodos: Participaron en el estudio 51 atletas masculinos sanos (edad: 18-39 años) de deportes de equipo, de resistencia y de fuerza. Se registró un diario de alimentación de 3 días y se calcularon los valores de PRAL dietético (mEq/día). Se midieron el pH y la gravedad específica de la orina. Para el análisis de datos se utilizó ANOVA de una vía con análisis post-hoc de Bonferroni y coeficiente de correlación de Pearson (r). Resultados: PRAL en los atletas de resistencia (25,34 mEq/día) fue menor en comparación con los atletas de equipo y de fuerza (46,12 y 46,47 mEq/día, respectivamente) (p= 0,023). El porcentaje de dieta alta en PRAL (≥15 mEq/día) fue más alto en los deportes de equipo (89,5%), seguido de los deportes de fuerza (83,3%) y de resistencia (60%). PRAL no se asoció con el estado de hidratación. Conclusión: Los requerimientos nutricionales típicos de las disciplinas deportivas se reflejan en el PRAL, por lo que se debe considerar el PRAL al preparar estrategias nutricionales para mejorar el rendimiento.