Effects of a 6-week on-court training program on the International Tennis Number (ITN) and a range of physical fitness characteristics in young tennis players.

The study aimed to (i) verify the effects of an on-court training program on the International Tennis Number (ITN) of young tennis players, as well as on a set of change of direction, linear sprint, and maximal oxygen uptake (VO2max) variables, and (ii) identify the main predictors of ITN. The sample consisted of 20 young male tennis players (mean age, 13.62 ± 0.23 years). Players underwent a 6-week on-court training program. The ITN and a number of change of direction variables (T-drill and repeated sprint ability), linear sprint (5 m, 10 m, and 20 m distances), and VO2max were measured. All variables improved significantly between the pre- and posttest (p < 0.001). The ITN (7.98 ± 6.06%, d = 0.82) and VO2max (6.77 ± 1.21%, d = 1.53) showed the greatest relative improvement with moderate to large effect sizes. The hierarchical linear model retained the time (estimate = 18.90, p < 0.001) and the T-drill (estimate = -64.77, p < 0.001) as significant predictors of the ITN. This indicates that the ITN improved significantly over the 6-week training program and that the T-drill test was the best and most significant predictor. Coaches and researchers are encouraged to monitor the ITN along with other physical fitness and technical variables. They can also use the T-drill test to understand the ITN of their players.

Detraining and Retraining Effects from a Multicomponent Training Program on the Functional Capacity and Health Profile of Physically Active Prehypertensive Older Women.

BACKGROUND: Resuming a physical exercise program after a period of cessation is common in older women. Monitoring the responses during this detraining (DT) and retraining (RT) may allow us to analyze how the body reacts to an increase and a reduction in physical inactivity. Therefore, we conducted a follow-up training, DT, and RT in prehypertensive older women to analyze the response to these periods. METHODS: Twenty-three prehypertensive older women (EG; 68.3 ± 2.8 years; 1.61 ± 0.44 m) performed 36 weeks of the multicomponent training program (MTP) followed by twelve weeks of DT plus eight weeks of RT. Fifteen prehypertensive older women (CG; 66.3 ± 3.2 years; 1.59 ± 0.37 m) maintained their normal routine. Functional capacity (FC), lipid, and hemodynamic profile were assessed before, during 24 and 36 weeks of the MTP, after 4 and 12 weeks of DT, and after 8 weeks of RT. RESULTS: After 24 weeks of the MTP, only SBP did not improve. Four weeks of DT did not affect lower body strength (30-CS), TC, or GL. Eight weeks of RT improved BP (SBP: -2.52%; ES: 0.36; p < 0.00; DBP: -1.45%; ES: 0.44; p < 0.02), handgrip strength (3.77%; ES: 0.51; p < 0.00), and 30-CS (3.17%; ES: 0.38; p < 0.04) compared with 36 weeks of the MTP. CONCLUSIONS: Eight weeks of RT allowed patients to recover the benefits lost with detraining, which after only four weeks affected them negatively, and the systematic practice of exercise contributed to greater regulation of BP since 24 weeks of the MTP proved not to be enough to promote positive effects of SBP.

Relationship between swimming speed, intra-cycle variation of horizontal speed, and Froude efficiency during consecutive stroke cycles in adolescent swimmers.

The purpose of this study was to investigate the relationship between swimming speed, intra-cycle variation of horizontal speed of displacement (dv), and Froude efficiency (ηF) in front-crawl during three consecutive stroke cycles. The sample consisted of 15 boys aged 16.07 ± 0.77 years and 15 girls aged 15.05 ± 1.07 years. Swimming speed, dv and ηF were measured during a 25 m front-crawl trial. Three consecutive stroke cycles were measured. Swimming speed showed a non-significant stroke-by-stroke effect (F = 2.55, p = 0.087, η2 = 0.08), but a significant sex effect (F = 90.46, p < 0.001, η2 = 0.76). The dv and ηF had the same trend as the swimming speed for the stroke-by-stroke effect, but a non-significant sex effect (p > 0.05). The Spearman correlation matrix between swimming speed and dv, and swimming speed and ηF showed non-significant correlations for the three stroke cycles in both sexes. However, the tendency of the former was not always inverse, and the latter was not always direct. Coaches and swimmers need to be aware that lower dvs are not always associated with faster swimming speeds and vice-versa, and that ηF is a predictor of swimming speed, not dv.

Effects of strength training in fibromyalgia on balance, neuromuscular performance, and symptomatic analysis: a 12-week study protocol.

Fibromyalgia affects skeletal muscles presenting with muscle stiffness, pain, and fatigue. The exercise practice is wellstabilized and suggested for the reduction of symptoms. However, there are some gaps in the literature related to balance and neuromuscular performance in a strength training protocol. The aim of this study is to structure a protocol to verify the effects of strength training applied over a short period, on balance, neuromuscular performance, and fibromyalgia symptoms. Additionally, we intend to analyze the effects of a short period of cessation of training. Participants will be recruited through flyers, internet advertisements, clinical referrals, health professionals, and email outreach. Volunteers will be randomly assigned to the control group or experimental group. Before the training period, symptoms (Fibromyalgia Impact Questionnaire, Visual Analog Scale), balance (force plate), and neuromuscular performance (medicine ball throw and vertical jump) will be assessed. Participants in the experimental group will perform strength training twice a week (50 min each), on alternate days, for 8 weeks (16 sessions). Then, 4 weeks of detraining will be completed. This training program will be carried out online, using real-time videos, and the participants will be divided into two groups with different schedules. The Borg scale will be used to monitor perceived effort in each session. There is a gap in the literature about exercise prescriptions for fibromyalgia. The supervised online intervention enables a wide range of participation. The strength exercises used (without the use of external materials and/or machines) and load (few repetitions per set) represent a novelty to training programming. Moreover, this training program respects the limitations and individuality of the volunteers, providing exercise adaptations. With positive results, the present protocol could be an easy-to-apply guideline with clear instructions on the details related to exercise prescription. Also, ensure the effectiveness of a low-cost and feasible treatment, especially for fibromyalgia patients. Clinical trial registration: https://clinicaltrials.gov/, identifier: NCT05646641.

The Benefits of Resistance Training in Obese Adolescents: A Systematic Review and Meta-analysis.

BACKGROUND: Physical activity is essential in acquiring healthy lifestyle behaviors in the early years of maturational development and preventing various diseases. Resistance training (RT) is fundamental for improving body composition and is increasingly recommended for obese adolescents. A systematic review and meta-analysis were performed to synthesize and analyze data on the effects of RT programs in this population, seeking to develop useful recommendations for health and sports professionals. METHODS: A search was performed using four databases (Web of Science, Scopus, PubMed, and ScienceDirect). According to specific inclusion criteria, twenty-one studies were selected to evaluate the impact of RT on body mass index (BMI), body fat, waist circumference, muscle strength, insulin sensitivity, lean mass and cardiorespiratory fitness. RESULTS: After the RT programs, the adolescents improved their muscle strength (SMD, 1.44; 95% CI: 0.76-2.12), cardiorespiratory fitness (SMD, 1.09; 95% CI: 0.15-2.04), BMI (SMD, 0.21; 95% CI: 0.07-0.35), waist circumference (SMD, 0.27; 95% CI: 0.06-0.47) and body fat (SMD, 0.20; 95% CI: 0.05-0.34). However, insulin sensitivity (SMD, 0.32; 95% CI: - 0.47 to 1.10) and lean mass (SMD, 0.12; 95% CI: - 0.06 to 0.31) did not reveal any changes. Different RT programs were used but it seems that 2-3 times/week ∼60 min/session of RT for 12 weeks should be recommended for positive changes. CONCLUSIONS: RT seems to be effective when the objective is to improve muscle strength, cardiorespiratory fitness and can be an efficient strategy to reduce obesity in adolescents by reducing body fat, waist circumference and body mass index. PROSPERO Registration number: CRD42022333411.

Understanding the Associations across Fibromyalgia-Related Fatigue, Depression, Anxiety, Self-Esteem Satisfaction with Life and Physical Activity in Portuguese and Brazilian Patients: A Structural Equation Modeling Analysis.

Background and Objectives: Fibromyalgia are heterogeneous and differ from patient to patient; however, the most reported are general myalgia and at specific points associated with fatigue and certain psychological adversities. Physical activity can mitigate the effects of the symptoms. However, the associations between fibromyalgia-related fatigue, self-esteem, anxiety, depression, satisfaction with life and physical activity are unclear. Therefore, the aim of the present study was to understand the associations between these symptoms and whether there are differences between these associations across two distinct cultures. Materials and Methods: A total of 473 women aged between 28 and 75 years (M = 49.27; SD ± 8.28) completed five questionnaires about fibromyalgia-related fatigue, physical activity, anxiety, depression, self-esteem, and satisfaction with life. Results: Fibromyalgia-related fatigue was positively associated with depression and anxiety, depression and anxiety were negatively associated with self-esteem, self-esteem was positively associated with satisfaction with life, satisfaction with life was positively associated with physical activity and there were no differences in terms of the perceptions and associations of these variables between Portuguese and Brazilian patients. Conclusions: Our results showed the significant role of associations between these variables and a similarity in the perception and relationship of the variables between the two cultures.

Force-velocity relationship in Paralympic powerlifting: two or multiple-point methods to determine a maximum repetition.

BACKGROUND: Due to the absence of evidence in the literature on Paralympic Powerlifting the present study investigated various methods to assess bench press maximum repetition and the way each method influences the measurement of minimum velocity limit (MVT), load at zero velocity (LD0), and force-velocity (FV). OBJECTIVE: To evaluate the precision of the multi-point method using proximal loads (40, 50, 60, 70, 80, and 90% of one repetition maximum; 1RM) compared to the four-point method (50, 60, 70, and 80% of 1RM) and the two-point method using distant loads (40 and 80% and 50 and 80% of 1RM) in in the MVT, LD0, and FV, in bench press performed by Paralympic Powerlifters (PP). METHODS: To accomplish this, 15 male elite PP athletes participated in the study (age: 27.7 ± 5.7 years; BM: 74.0 ± 19.5 kg). All participants performed an adapted bench press test (free weight) with 6 loads (40, 50, 60, 70, 80, and 90% 1RM), 4 loads (50, 60, 70, and 80% 1RM), and 2 loads (40-80% and 50-80% 1RM). The 1RM predictions were made by MVT, LD0, and FV. RESULTS: The main results indicated that the multiple (4 and 6) pointsmethod provides good results in the MVT (R2 = 0.482), the LD0 (R2 = 0.614), and the FV (R2 = 0.508). The two-point method (50-80%) showed a higher mean in MVT [1268.2 ± 502.0 N; ICC95% 0.76 (0.31-0.92)], in LD0 [1504.1 ± 597.3 N; 0.63 (0.17-0.86)], and in FV [1479.2 ± 636.0 N; 0.60 (0.10-0.86)]. CONCLUSION: The multiple-point method (4 and 6 points) and the two-point method (40-80%) using the MVT, LD0, and FV all showed a good ability to predict bench press 1RM in PP.

Effects of different protocols of physical exercise on fibromyalgia syndrome treatment: systematic review and meta-analysis of randomized controlled trials.

Physical exercise has been used as a form of treatment for fibromyalgia, however, the results indicate the need for further investigations on the effect of exercise on different symptoms. The aim of the study was to synthesize and analyse studies related to the effect of exercise in individuals with fibromyalgia and provide practical recommendations for practitioners and exercise professionals. A search was carried out in the Web of Science, PubMed, and Scopus databases in search of randomized clinical trials (RCT) written in English. A meta-analysis was performed to determine the effectiveness of different types of exercise on the fibromyalgia impact questionnaire (FIQ), and the protocol period and session duration on the pain outcome. Eighteen articles were eligible for a qualitative assessment and 16 were included in the meta-analysis. The exercise showed large evidence for the association with a reduction in the FIQ (SMD - 0.98; 95% CI - 1.49 to - 0.48). Protocols between 13 and 24 weeks (SMD - 1.02; 95% CI - 1.53 to - 0.50), with a session time of less than 30 min (SMD - 0.68 95% CI - 1.26 to - 0.11) or > 30 min and < 60 min (SMD - 1.06; 95% CI - 1.58 to - 0.53) presented better results. Better results were found after combined training protocols and aerobic exercises. It is suggested that exercise programs lasting 13-24 weeks should be used to reduce pain, and each session should last between 30 and 60 min. In addition, the intensity should always be carried out gradually and progressively.PROSPERO registration number CRD42020198151.

Young Swimmers' Classification Based on Performance and Biomechanical Determinants: Determining Similarities Through Cluster Analysis.

The aim of this study was to classify and identify young swimmers' performance, and biomechanical determinant factors, and understand if both sexes can be clustered together. Thirty-eight swimmers of national level (22 boys: 15.92 ± 0.75 years and 16 girls: 14.99 ± 1.06 years) were assessed. Performance (swim speed at front crawl stroke) and a set of kinematic, efficiency, kinetic, and hydrodynamic variables were measured. Variables related to kinetics and efficiency (p < .001) were the ones that better discriminated the clusters. All three clusters included girls. Based on the interaction of these determinant factors, there are girls who can train together with boys. These findings indicate that not understanding the importance of the interplay between such determinants may lead to performance suppression in girls.

Exploring the Relationship between Fibromyalgia-Related Fatigue, Physical Activity, and Quality of Life.

The symptoms of fibromyalgia are varied, including general muscle pain and pain at specific points (also called tender points), excessive fatigue, anxiety, depression, and some psychological problems that can have a negative impact on quality of life. Physical activity is a widely used option by health professionals to alleviate the effects of this syndrome. However, there is no clear information on the possible mediating role of physical activity in the relationship between fibromyalgia-related fatigue and quality of life. Therefore, this study aims to evaluate the relationship between fibromyalgia-related fatigue and quality of life, and to investigate the mediating role of physical activity in patients with this syndrome. METHODS: In a cross-sectional study, 237 Portuguese women aged 28 to 75 years (M = 49.12; SD ± 8.87) and 117 Brazilian women aged 20 to 69 years (M = 46.72; SD ± 8.38) were recruited to participate in this study. These patients completed three valid and reliable questionnaires related to the assessment of fibromyalgia-related fatigue (MDF-Fibro-17), physical activity (IPAQ), and quality of life (SF-36). RESULTS: Both samples had scores above the midpoint for all dimensions of fibromyalgia-related fatigue and scores below the midpoint for quality of life. Physical activity had no mediating effect in either sample, as the total indirect effect was not significant. CONCLUSIONS: Physical activity does not mediate the relationship between fatigue and quality of life. However, the results also show that the fatigue dimensions associated with fibromyalgia had a negative and significant association with physical and mental health indicators in both samples. Thus, patients with FM with higher scores on fatigue-related symptoms might suffer more from physical and mental health, both of which are related to quality of life.

Benefits of aquatic exercise in adults with and without chronic disease-A systematic review with meta-analysis.

Aquatic exercise is being increasingly recommended for healthy individuals as well as people with some special health conditions. A systematic review with meta-analysis was performed to synthesize and analyze data on the effects of water-based training (WT) programs on health status and physical fitness of healthy adults and adults with diseases to develop useful recommendations for health and sports professionals. We searched three databases (PubMed, Web of Science, and Scopus) up to June 2021 for randomized trials that examined WT in adults. A total of 62 studies were included, of which 26 involved only healthy individuals and 36 focused on adults with chronic diseases. In the healthy group, the effects of WT on strength, balance, and cardiorespiratory fitness were beneficial, indicating the usefulness of performing WT for at least 12 weeks (2-3x/week, 46-65 min/session). Among adults with diseases, improvements were observed in patients with fibromyalgia (in balance and cardiorespiratory fitness), bone diseases (pain, balance, flexibility, and strength), coronary artery disease (strength and anthropometry), hypertension (quality of life), stroke (quality of life), diabetes (balance and quality of life), multiple sclerosis (quality of life and balance), and Parkinson's disease (pain, gait, cardiorespiratory fitness, and quality of life). Research is required to determine the effects of WT on patients with heart disease, especially coronary artery disease. In adults with chronic disease, benefits in physical fitness and/or other health-related measures were mainly observed after 8-16 weeks of training. WT is an effective physical activity when the intention is to enhance health and physical fitness in healthy adults and adults with chronic diseases.

Propulsive forces in human competitive swimming: a systematic review on direct assessment methods.

Human propulsive forces are a key-factor to enhance swimming performance, but there is scarce knowledge when using direct assessments. The aim of this review was to analyse the evidence about human propulsive forces in competitive swimming measured by direct assessment methods. A search up to 30 June 2020 was performed in Web of Science, PubMed, and Scopus databases. The Downs and Black Quality Assessment Checklist was used to assess the quality index (QI) of the included studies. Out of 2530 screened records, 35 articles met the inclusion criteria. Tethered-swimming and differential pressure sensors allow directly measure propulsive forces. Cross-sectional designs measured peak and mean propulsive force during the front crawl stroke and including men/boys (≥15 years-old) at different competitive levels were mostly reported. Men are more able to show higher propulsive forces than women counterparts. Short- and long-term effects were observed while using dry-land and in-water training programmes. The magnitude of propulsive force is dependent on the type of assessment method, swimming stroke, number of body limbs and gender. While the short-term effects supporting the different training programmes lead to an increase in propulsive force, there is a lack of long-term evidence.

Force Production and Coordination from Older Women in Water Fitness Exercises.

The aim of this study was to compare bilateral propulsive forces and coordination while exercising at static and dynamic conditions in the water. A total of 27 older women (age: 65.1 ± 6.7 years old) performed the following exercises: (i) horizontal upper-limbs adduction (HA; static condition) and (ii) rocking horse (RH; dynamic condition) through an incremental protocol with music cadences from 105 up to 150 b·min-1. The duration of each trial was set at 30 second (sec). Propulsive peak force (in Newton, N) of dominant (PFD) and nondominant (PFND) upper limbs was retrieved using hand sensors coupled to a differential pressure system. Significant differences in force production were found between static and dynamic exercises at higher cadences (120, 135, and 150 b·min-1). The static condition elicited higher bilateral propulsive forces and a more symmetric pattern. The in-water static exercise with bilateral action from the upper limbs proved to be the most appropriate strategy for older women to work strength and to reduce asymmetries.

Evaluation of Lower Limb Arteriovenous Diameters in Indoor Soccer Athletes: Arterial Doppler Ultrasound Study.

The purpose of this study was to analyze the arterial and venous diameters of lower limbs in indoor soccer athletes and non-athletes using Doppler ultrasound to identify the differences in the variation of arterial and venous diameters between groups. Additionally, we intended to verify the differences of arterial and venous diameters between the skilled member (right member) and the not skilled member in each group. 74 male volunteers, aged between 19 and 30 years old, were divided in a group of athletes (n = 37, 24 ± 2.7 years, soccer players from national championship), and a group of non-athletes (n = 37, 26 ± 2.83 years). Vascular lower limb was assessed using Doppler ultrasound (Philips HD7 echograph with linear transducer 7-12 MHz). The athletes showed higher diameters of right common femoral artery (p = 0.009; moderate), left common femoral artery (p = 0.005; moderate), right deep femoral artery (p = 0.013; moderate), right popliteal artery (p = 0.003; moderate), and left popliteal artery (p = 0.017; small) than non-athletes. Veins' diameters were also higher in athletes, specifically the right deep femoral vein (p ≤ 0.001; large), left deep femoral vein (p ≤ 0.001; large), right popliteal vein (p ≤ 0.001; large), and left popliteal vein (p ≤ 0.001; large). Differences were found between the skilled and non-skilled leg in athletes in the popliteal vein (7.68 ± 1.44 mm vs. 7.22 ± 1.09 mm, respectively, p < 0.003). It seems that futsal athletes have superior mean diameters of lower limbs arteries and veins of the deep venous system to non-athletes. Moreover, the veins presented greater dilation, namely of the leg of the skilled lower limb.