Acute effects of sodium citrate supplementation on competitive performance and lactate level of elite fitness challenge athletes: A crossover, placebo-controlled, double-blind study.

Purpose: The performance of sodium citrate has been investigated in high-intensity exercises, but fewer studies have addressed the role of citrate in weight-bearing exercises. Methods: Twenty fitness challenge athletes, aged 24-32 years, volunteered to participate in this crossover, placebo-controlled, double-blind study. Initially, ten athletes were given a placebo and asked to complete a fitness challenge (i.e., chin-ups, squat jumps, dips, walking lunges, sit-ups, and burpees-devil press). Another ten athletes were supplemented with sodium citrate 0.5 g/kg body mass supplements 3 h prior to performing the fitness challenges. The same procedures were completed two days later with the supplement and placebo dextrose groups switched in a cross-over design. Athletes and assessors were blinded for the experimental condition (placebo vs. verum). Lactate levels were measured 5 min after exercise. The athletes' performance on each item of the fitness challenge as well as their lactate levels, were compared. Differences between the means of the measured variables were contrasted using a dependent t-test. Results: Supplementing sodium citrate substantially improved athletes' performance in all six fitness challenge items (p < 0.05, 0.69

Endometriosis and physical activity: A narrative review.

Endometriosis is a painful gynecological disorder that affects many women. Constant treatments and contraception changes affect women looking for solutions to treat and limit the problems caused by endometriosis. The current narrative review discusses the effects of physical activity on the management, pain, and quality of life in patients with endometriosis. Findings suggest that body awareness practices such as Hatha yoga, the Jacobson method, and progressive muscle relaxation reduce pain and stress and improve the quality of life associated with endometriosis. It also highlights the current knowledge gap on available evidence and future research. Moreover, care must be taken when considering patients' physical abilities and goals and avoiding intense physical activities. The forms of endometriosis and its symptoms vary from one woman to another, so it is important to perform studies with various nonmedicinal or surgical techniques. It is important to continue randomized controlled trials to obtain more data on the benefits of physical activity in women with endometriosis and also to identify what types of activities could be beneficial to combat pain symptoms and improve the daily lives of women with endometriosis.

The Effects of Resistance Training on Muscular Fitness, Muscle Morphology, and Body Composition in Elite Female Athletes: A Systematic Review.

BACKGROUND: Well programmed strength and conditioning training is an indispensable part of the long-term training process for athletes in individual and team sports to improve performance and prevent injuries. Yet, there is a limited number of studies available that examine the effects of resistance training (RT) on muscular fitness and physiological adaptations in elite female athletes. OBJECTIVES: This systematic review aimed to summarize recent evidence on the long-term effects of RT or combinations of RT with other strength-dominated exercise types on muscular fitness, muscle morphology, and body composition in female elite athletes. MATERIALS AND METHODS: A systematic literature search was conducted in nine electronic databases (Academic Search Elite, CINAHL, ERIC, Open Access Theses and Dissertations, Open Dissertations, PsycINFO, PubMed/MEDLINE, Scopus, and SPORTDiscus) from inception until March 2022. Key search terms from the MeSH database such as RT and strength training were included and combined using the operators "AND," "OR," and "NOT". The search syntax initially identified 181 records. After screening for titles, abstracts, and full texts, 33 studies remained that examined the long-term effects of RT or combinations of RT with other strength-dominated exercise types on muscular fitness, muscle morphology, and body composition in female elite athletes. RESULTS: Twenty-four studies used single-mode RT or plyometric training and nine studies investigated the effects of combined training programs such as resistance with plyometric or agility training, resistance and speed training, and resistance and power training. The training duration lasted at least 4 weeks, but most studies used ~ 12 weeks. Studies were generally classified as 'high-quality' with a mean PEDro score of 6.8 (median 7). Irrespective of the type or combination of RT with other strength-dominated exercise regimens (type of exercise, exercise duration, or intensity), 24 out of 33 studies reported increases in muscle power (e.g., maximal and mean power; effect size [ES]: 0.23 < Cohen's d < 1.83, small to large), strength (e.g., one-repetition-maximum [1RM]; ES: 0.15 < d < 6.80, small to very large), speed (e.g., sprint times; ES: 0.01 < d < 1.26, small to large), and jump performance (e.g., countermovement/squat jump; ES: 0.02 < d < 1.04, small to large). The nine studies that examined the effects of combined training showed significant increases on maximal strength (ES: 0.08 < d < 2.41, small to very large), muscle power (ES: 0.08 < d < 2.41, small to very large), jump and sprint performance (ES: 0.08 < d < 2.41, small to very large). Four out of six studies observed no changes in body mass or percentage of body fat after resistance or plyometric training or combined training (ES: 0.026 < d < 0.492, small to medium). Five out of six studies observed significant changes in muscle morphology (e.g., muscle thickness, muscle fiber cross-sectional area; ES: 0.23 < d < 3.21, small to very large). However, one study did not find any changes in muscle morphology (i.e., muscle thickness, pennation angle; ES: 0.1 < d < 0.19, small). CONCLUSION: Findings from this systematic review suggest that RT or combined RT with other strength-dominated exercise types leads to significant increases in measures of muscle power, strength, speed, and jump performance in elite female athletes. However, the optimal dosage of programming parameters such as training intensity and duration necessary to induce large effects in measures of muscular fitness and their physiological adaptations remain to be resolved in female elite athletes.

Pulmonary diffusing capacity measured by NO/CO transfer in Tunisian boys.

BACKGROUND: The diffusing capacity, which measures gas-exchange, uses reference values based on data from American or European studies. There are currently no reference values of pulmonary diffusing capacity (TL) and its components, such as the conductance of the membrane (Dm) and capillary lung volume (Vc) for healthy North African children. OBJECTIVES: We determined the prediction equations-reference values for TL, Dm, Vc and the alveolar volume (VA) in healthy Tunisian boys. METHODS: Values of Vc, Dm, TL, and VA were measured by the NO/CO transfer method, using a single breath maneuver in 118 Tunisian boys (8-14 years old) at rest. We performed linear regression analysis of the pulmonary parameters and independent variables, such as height, weight, and age. RESULTS: The reference equations for pulmonary diffusing capacity for carbon monoxide (TLCO ) was 0.201 × weight (kg) + 8.979; for TLNO was 0.76 × height (cm)-24.383; for Dm was 0.388 × height (cm)- 12.555 and for VA was 0.34 × height (cm)-3.951. Vc increased significantly with weight (P < .05) but not with age (P > .05). CONCLUSIONS: References norms for TLCO and TL for nitric oxide and its components in young Tunisian boys are similar to data from other countries. The prediction equations we developed can be extended to clinical practice in Tunisia and can be considered for use in neighboring North African countries.

Effects of Combined Balance and Strength Training on Measures of Balance and Muscle Strength in Older Women With a History of Falls.

OBJECTIVE: We investigated the effects of combined balance and strength training on measures of balance and muscle strength in older women with a history of falls. METHODS: Twenty-seven older women aged 70.4 ± 4.1 years (age range: 65 to 75 years) were randomly allocated to either an intervention (IG, n = 12) or an active control (CG, n = 15) group. The IG completed 8 weeks combined balance and strength training program with three sessions per week including visual biofeedback using force plates. The CG received physical therapy and gait training at a rehabilitation center. Training volumes were similar between the groups. Pre and post training, tests were applied for the assessment of muscle strength (weight-bearing squat [WBS] by measuring the percentage of body mass borne by each leg at different knee flexions [0°, 30°, 60°, and 90°], sit-to-stand test [STS]), and balance. Balance tests used the modified clinical test of sensory interaction (mCTSIB) with eyes closed (EC) and opened (EO), on stable (firm) and unstable (foam) surfaces as well as spatial parameters of gait such as step width and length (cm) and walking speed (cm/s). RESULTS: Significant group × time interactions were found for different degrees of knee flexion during WBS (0.0001 < p < 0.013, 0.441 < d < 0.762). Post hoc tests revealed significant pre-to-post improvements for both legs and for all degrees of flexion (0.0001 < p < 0.002, 0.697 < d < 1.875) for IG compared to CG. Significant group × time interactions were found for firm EO, foam EO, firm EC, and foam EC (0.006 < p < 0.029; 0.302 < d < 0.518). Post hoc tests showed significant pre-to-post improvements for both legs and for all degrees of oscillations (0.0001 < p < 0.004, 0.753 < d < 2.097) for IG compared to CG. This study indicates that combined balance and strength training improved percentage distribution of body weight between legs at different conditions of knee flexion (0°, 30°, 60°, and 90°) and also decreased the sway oscillation on a firm surface with eyes closed, and on foam surface (with eyes opened or closed) in the IG. CONCLUSION: The higher positive effects of training seen in standing balance tests, compared with dynamic tests, suggests that balance training exercises including lateral, forward, and backward exercises improved static balance to a greater extent in older women.

Differences in Trunk Strength Between Weightlifters and Wrestlers.

Investigations of trunk strength with high-level athletes are limited. The purpose of this study was to compare maximal concentric isokinetic trunk extension and flexion torque, power, and strength ratios between high-level weightlifters (n = 20), wrestlers (n = 20) and a control (n = 25) population. Isokinetic dynamometry was used to evaluate peak torque, power and strength ratios during seated trunk extension/flexion actions at 60°/s and 180°/s. There were no significant anthropometric differences between groups. Overall, trunk isokinetic force variables as a function of the increase in angular velocity, showed a decrease in peak torque, but an increase in power (athletes and controls). Compared to the control group, athletes demonstrated significantly higher trunk extension torque (+67.05 N·m, ES = 0.81) and power (+49.28 N·m, ES = 0.82) at 60°/s and 180°/s, respectively. Athletes produced significantly greater trunk flexion-extension ratios at 60°/s and 180°/s (ES = 0.80-0.47) than controls. Weightlifters and wrestlers exhibited significantly higher extensor than flexor torque at all angular velocities. Weightlifters demonstrated greater torque (ES = 0.79) than wrestlers at 60°/s. The wrestlers' average power was significantly higher (ES = 0.43) than weightlifters at 180°/s. There were no significant ratio differences between wrestlers (66.23%) and weightlifters (72.06%). Weightlifters had stronger extensor muscles at 60°/s, whereas wrestlers had higher power at 180°/s for extensor muscles. It was postulated that the extensor muscles were stronger than the flexors to ensure trunk stabilisation, and for prevention of injuries. These differences seem to be associated to the movements that occur in each sport in terms of both muscle actions and contractile forces.

Relationship of Pre-season Training Load With In-Season Biochemical Markers, Injuries and Performance in Professional Soccer Players.

INTRODUCTION: There is controversy in the literature in regards of the link between training load and injury rate. Thus, the aims of this non-interventional study were to evaluate relationships between pre-season training load with biochemical markers, injury incidence and performance during the first month of the competitive period in professional soccer players. MATERIALS AND METHODS: Healthy professional soccer players were enrolled in this study over two pre-season periods. Data sets were available from 26 players during the first season (2014-2015) and 24 players during the second season (2015-2016) who completed two pre-season periods (6 weeks each). External training load was assessed from all athletes during training using Global Positioning System (GPS). Internal training load was monitored after each training session using rate of perceived exertion (RPE). Before and after each pre-season, blood samples were taken to determine plasma lactate dehydrogenase (LDH), creatine kinase (CK) and C-reactive protein (CRP). Injury incidence and overall performance (ranking of the team after the first five official games of the championship) were recorded for both seasons separately. RESULTS: There was no statistically significant difference in mean RPE values of the two-preparation periods (2737 ± 452 and 2629 ± 786 AU, p = 0.492). The correlational analysis did not reveal significant associations between internal and external training load (RPE and GPS data) and biological markers. There was a significant positive correlation between RPE and LDH during the 2015/2016 season (r = 0.974, p = 0.001). In addition, a significant negative correlation was found between total distance >20 km/h and CRP during the 2015-2016 season (r = -0.863, p = 0.027). The injury rates for the two seasons were 1.76 and 1.06 per 1000 h exposure for the 2014-2015 and 2015-2016 seasons, respectively (p = 0.127). CONCLUSION: Our study showed that pre-season training load is not associated with overall team performance. This association is most likely multifactorial and other factors (e.g., technical and tactical level of the team, opponents, environment) may play an important role for the collective team performance. Our findings may help coaches to better prepare their athletes during pre-season.

Progressive circuit resistance training improves inflammatory biomarkers and insulin resistance in obese men.

BACKGROUND: Circuit resistance training (CRT) is a time-efficient exercise modality for improving skeletal muscle and cardiovascular fitness. But the beneficial role of CRT in obese individuals is still not well understood. This study explores the reducing effects of progressive CRT on inflammatory biomarkers and cardiometabolic risk factors in obese young men. METHODS: Thirty obese men (Body mass index (BMI): 30.67 ±â€¯3.06; age: 23 ±â€¯3.2 years) were divided into CRT and control groups. The CRT was performed for eight-weeks (3 times/week, 65-85% of 1 repetition maximum). Fasting blood samples were taken pre and post intervention for analyzing apelin, chemerin, serum amyloid A (SAA), C reactive protein concentrations (CRP), lipid profile, and insulin resistance index. The data were assessed by two-way repeated measures ANOVA. RESULTS: Body mass, BMI and waist to hip ratio (WHR) were significantly decreased after training intervention (P < .05). Compared to the control group, the plasma concentrations of Chemrin (P = .038), SAA (P = .004), insulin (P < .001), insulin resistance index (P < .001), total cholesterol (P = .033), triglyceride (P < .001), and low-density lipoprotein (P = .039), were significantly mitigated in the CRT group, but high-density lipoprotein plasma levels increased in the CRT group compared to that of the control group (P = .035). There was no significant difference between two groups in apelin and CRP (P > .05). Moreover, insulin resistance was positively correlated with apelin (r = 0.56) and chemerin (r = 0.51). Also, chemerin had a positive correlation with SAA (r = 0.49), and WHR (r = 0.54). CONCLUSION: CRT caused an improvement in inflammation and cardiometabolic risk factors in young obese men, and this improvement was accompanied by decreased insulin resistance.

Comparison of isokinetic trunk flexion and extension torques and powers between athletes and nonathletes.

This study is aimed to perform and compare maximal concentric isokinetic trunk extension and flexion torques and powers between high-level athletes and a control population. In addition, the ratio of isokinetic trunk extension and flexion torques was measured, and compared between groups. Eighteen high-level male athletes and 15 male nonathletes without low back pain were recruited. Subjects performed isokinetic trunk extension and flexion at 60°/sec, 90°/sec, and 120°/sec through a maximal range of motion in a dynamometer. Trunk extension torque of athletes was significantly higher than in nonathletes at 60°/sec and 90°/sec but not at 120°/sec. Trunk extension power of athletes was significantly higher than the control group at 90°/sec and 120°/sec but not at 60°/sec. There was no difference between the athlete and nonathlete groups in respect of trunk flexion torque or power at any angular velocity. Consequently, the ratio of trunk flexion to extension strength was greater in nonathletes than in athletes. Trunk extension and flexion torques tended to decrease, and trunk extension and flexion powers tended to increase, with increasing angular velocity. High-level athletes seem to display preferentially greater trunk extension strength and power in comparison with trunk flexion strength, compared to nonathletes. This could be caused by the use of strength training exercises such as squats and deadlifts, or it may be associated with greater athletic performance.

Strength Training Reduces Injury Rate in Elite Young Soccer Players During One Season.

The purpose of this study was to examine the effect of strength training on physical fitness parameters and injuries occurrence in young elite soccer players. Fifty-two elite young soccer players (13-14 years) were divided on a randomized order into experimental group (EG, n = 26) and control group (CG, n = 26). For EG, 2 to 3 sessions of strength training (90 minutes) were introduced weekly in their training program for 12 weeks (4 × 3 weeks separated by 1-week recovery). Sprint tests (10-20-30 m), T-test time, and jumping tests were measured at the start (T0), at the middle (T1), and at the end of the experiment period (T2). The injury rate was recorded by the medical and fitness training staff throughout the soccer season. Compared to CG, EG performed significantly better in sprint running and T-test time at T2 (p < 0.01). Similarly, the improvement amount for jumping tests was significantly greater (p ≤ 0.05) in EG than in CG. A total of 17 injuries were recorded over the soccer season. The rate was higher in CG (13 injuries) than in training group (4 injuries). This study showed that strength training accurately and efficiently scheduled in youth soccer players, induced performance improvement, and reduced the rate of injuries.