The Effect of Caffeine Supplementation on Female Volleyball Players' Performance and Wellness during a Regular Training Week.

BACKGROUND: caffeine is an ergogenic aid that still needs to be investigated in women's sports performance. METHODS: Eight semi-professional women's volleyball players (height = 1.63 ± 0.08 m; weight = 66.67 ± 4.74 kg) voluntarily participated in this study. A randomized crossover design was implemented where players underwent caffeine and placebo conditions. In the caffeine condition, participants consumed 5 mg/kg of caffeine based on their body weight before acute training. The evaluations were performed over two weeks of training. In both conditions, the countermovement jump, repeated jumps for 15 s, and handgrip tests were performed. The change of direction was assessed using the 505 test. Well-being was also assessed with a wellness questionnaire. A repeated measures ANOVA and correlation analysis were performed. RESULTS: The repeated measures ANOVA revealed a main effect of supplementation (F (1.7) = 8.41, p = 0.02, η2 = 0.54) across the training week on physical performance. Additionally, there was a positive effect on perceived fatigue (F (1.7) = 7.29, p = 0.03, η2 = 0.51). CONCLUSIONS: Caffeine improved performance and fatigue parameters over one week of training. Further research is needed on women, focusing on physical performance and wellbeing, especially during intense periods.

Supplementation of Re-Esterified Docosahexaenoic and Eicosapentaenoic Acids Reduce Inflammatory and Muscle Damage Markers after Exercise in Endurance Athletes: A Randomized, Controlled Crossover Trial.

This study aimed to analyse the effect of 10 weeks of a highly concentrated docosahexaenoic acid (DHA) + eicosapentaenoic (EPA) supplementation (ratio 8:1) on strength deficit and inflammatory and muscle damage markers in athletes. Fifteen endurance athletes participated in the study. In a randomized, double-blinded cross-over controlled design, the athletes were supplemented with a re-esterified triglyceride containing 2.1 g/day of DHA + 240 mg/day of EPA or placebo for 10 weeks. After a 4-week wash out period, participants were supplemented with the opposite treatment. Before and after each supplementation period, participants performed one eccentric-induced muscle damage exercise training session (ECC). Before, post-exercise min and 24 and 48 h after exercise, muscle soreness, knee isokinetic strength and muscle damage and inflammatory markers were tested. No significant differences in strength deficit variables were found between the two conditions in any of the testing sessions. However, a significant effect was observed in IL1ß (p = 0.011) and IL6 (p = 0.009), which showed significantly lower values after DHA consumption than after placebo ingestion. Moreover, a significant main effect was observed in CPK (p = 0.014) and LDH-5 (p = 0.05), in which significantly lower values were found after DHA + EPA consumption. In addition, there was a significant effect on muscle soreness (p = 0.049), lower values being obtained after DHA + EPA consumption. Ten weeks of re-esterified DHA + EPA promoted lower concentrations of inflammation and muscle damage markers and decreased muscle soreness but did not improve the strength deficit after an ECC in endurance athletes.

Muscle damage and inflammation biomarkers after two ultra-endurance mountain races of different distances: 54 km vs 111 km.

The aims of this study were 1) to describe the effects of a 54 km and 111 km ultra-endurance mountain race on the biomarkers of muscle damage and inflammation, 2) to compare the effects between the two races regarding the biomarkers of muscle damage and inflammation. Sixteen ultra-endurance amateur runners volunteered to participate in this study. Ten runners completed a 54 km race (Group 1; age: 27.0 ±â€¯5.7; height: 179.5 ±â€¯5.8 cm; and body mass: 77.3 ±â€¯10.7 kg) and six completed a 111 km race (Group 2; age: 30.5 ±â€¯8.0; height: 179.4 ±â€¯5.5 cm; and body mass: 76.2 ±â€¯9.4 kg). Blood samples were taken at five different points during the investigation, 24 h before the race, immediately post-race, and again at 24, 48, and 72 h after the race. There were increases in leukocyte (Group 1: p ≤ .001, ES = 2.8; Group 2: p = .001, ES = 3.5) and platelet concentrations (Group 1: p ≤ .001, ES = 2.3; Group 2: p = .02, ES = 1.7) post-races. Significant inter-race differences were also observed in leukocyte at 72 h (Group 1: 5.5 ±â€¯0.9, Group 2: 4.2 ±â€¯0.9, p = .012, ES = 1.5). Erythrocytes, hematocrit and hemoglobin concentration decreased after 54 km and 111 km races at 24, 48 and 72 h (p ≤.001, ES = 2.0-3.18). Serum uric acid concentration increased after the 54 km race (pre = 4.9 ±â€¯1.2 - post = 7.3 ±â€¯1.0 8 mg/dl; p ≤ .001, ES = 2.4), and also the 111 km race (pre = 5.3 ±â€¯0.9 - post = 6.7 ±â€¯0.8 mg/dl; p < .008, ES = 2.2). GPT, GOT and LDH had changed by the end of the races (p < .05) and differences between the groups were observed in GOT post-race (p = .008, ES = 1.7) 24 h (p = .004, ES = 1.8), 48 h (p = .007, ES = 1.6), and 72 h (p = .02, ES = 1.4) and also in LDH at 24, 48, 72 h. Serum creatinine decreased post-race in Group 1 (pre = 1.1 ±â€¯0.1 - post = 1.4 ±â€¯0.2 mg/dl; p = .001, ES = 1.5) and Group 2 (pre = 1.2 ±â€¯0.1, post = 1.5 ±â€¯0.2; p = .002, ES = 3.3) along with CK and myoglobin. In addition, values did not return to baseline levels after 72 h in Group 2 for C-reactive protein, myoglobin, and CK. Differences between the races were also observed post-race in Troponin I (Group 1 = 0.06 ±â€¯0.05, 111 km = 0.02 ±â€¯0.01 µg/l, p = .047, ES = 1.1) and C-reactive protein post-race (Group 2 = 2.5 ±â€¯1.6, 111 km = 18.2 ±â€¯6.4 mg/l, p ≤ .001, ES = 4.4) at 24 and 48 h. The athletes had increased concentrations of markers associated with damage, inflammation, muscle injury and cardiac damage after the races. Furthermore, athletes who completed the greater distance (111 km) had higher concentrations of the markers associated with muscle damage and muscle inflammation which remained changed for a period of 72 h. However, the participants of the 'shorter race' showed higher values associated with cardiac damage. Consequently, athletes who take part in these kinds of races should wait at least 72 h before training with high load.

[Effect of quinua (Chenopodium quinoa)consumption as a coadjuvant in nutritional intervention in prediabetic subjects]. / Efecto del consumo de quinua (Chenopodium quinoa)como coadyuvante en la intervención nutricional en sujetos prediabéticos.

INTRODUCTION: Quinoa is a pseudocereal containing low glycemic index carbohydrates, dietary fiber, high biological value protein, phytosterols, and n-3 and n-6 fatty acids, which has generated interest in prediabetes nutritional interventions. This randomized (2:1), placebo-controlled, double-blind study evaluated the effects of processed quinoa on body mass index (BMI), glycated hemoglobin (HbA1c), fasting plasma glucose (FPG) and the satiation and fullness (complete) degree in prediabetic patients. MATERIAL AND METHOD: Thirty patients were randomized (2:1) in two study arms: Kuska Active product (processed quinoa) and placebo (maltodextrin), with an intake period of 28 days. BMI, HbA1c and FPG were determined before starting treatment and at 28-day intake. Satiety and fullness sensation were just assessed by visual analog scale (VAS) at the day 28. ANOVA was performed for repeated measures with two factors to study (within-subject factor: time; intersubject factor: product consumed) to demonstrate the effectiveness of processed quinoa on the study variables. RESULTS: Twenty-nine patients (placebo, n = 10; quinoa, n = 19) completed the study, and the quinoa group shows a significant decrease in BMI (p < 0.05) and HbA1c values (p < 0.001), and an increase in the satiation and fullness (complete) degree (p < 0.001). No significant differences were found in FPG levels from baseline to post-intake period. CONCLUSIONS: The results show that processed quinoa intake during 28 days decreases BMI and HbA1c levels, maintains FPG levels, and incr eases the satiation and fullness (complete) degree in prediabetic patients.

Muscle damage, physiological changes, and energy balance in ultra-endurance mountain-event athletes.

The biological response to ultra-endurance mountain race events is not yet well understood. The aim of this study was to determine the biochemical and physiological changes after performing an ultra-endurance mountain race in runners. We recruited 11 amateur runners (age: 29.7 ± 10.2 years; height: 179.7 ± 5.4 cm; body mass: 76.7 ± 10.3 kg). Muscle damage, lactate concentration, energy balance, rating of perceived exertion (RPE), heart rate (HR), heart rate variability (HRV), body composition changes, and jump performance were analyzed before, during (only lactate, HR, and HRV), and after the race. Athletes completed 54 km in 6 h, 44 min (±28 min). After the race, myoglobin and creatine kinase concentration increased from 14.9 ± 5.2 to 1419.9 ± 1292.1 µg/L and from 820.0 ± 2087.3 to 2421.1 ± 2336.2 UI/L, respectively (p < 0.01). In addition, lactate dehydrogenase and troponin I significantly increased after the race (p < 0.01). Leukocyte and platelet count increased by 180.6% ± 68.9% and 23.7% ± 11.2%, respectively (p < 0.001). Moreover, after the competition, athletes presented a 3704 kcal negative energy balance; a significant increase in RPE values; a decrease in countermovement and squat jump height; and a decrease in body mass and lower limb girths. During the event, lactate concentration did not change and subjects presented a mean HR of 158.8 ± 17.7 beats/min, a significant decrement in vagal modulation, and a significant increase in sympathetic modulation. Despite the relative "low" intensity achieved, ultra-endurance mountain race is a stressful stimulus that produces a high level of muscle damage in the athletes. These findings may help coaches to design specific training programs that may improve nutritional intake strategies and prevent muscle damage.