Is isokinetic shoulder strength a determinant of serve ball velocity in tennis?

The tennis serve is closely related to the quality of the tennis match. However, the isokinetic parameters associated with the tennis serve are still unclear. The aim of this study was to investigate the relationships between ball velocity and isokinetic shoulder strength in tennis serve and to determine isokinetic strength parameters that can predict tennis serve velocity. A total of 13 elite male athletes (16.8 ± 1.5 years) voluntarily participated in the study. The athletes' shoulder internal-external rotation, extension-flexion and abduction-adduction strengths were measured with 5-5-15 repetitions at 60°/s, 180°/s, 240°/s angular velocities. Later, the athletes' 1st, 2nd, and average serve ball speeds were determined using a handheld radar gun. Significant correlations were found between ball speed and isokinetic tennis serve strength (r = 0.556-0.819; p < 0.05). The correlations between ball speed and isokinetic strength performance were higher at 180°/s and 240°/s angular velocities. Extension (240°/s; r = 0.819), flexion (180°/s; r = 0.755), abduction (240°/s; r = 0.733), adduction (240°/s; r = 0.684) and internal rotation (180°/s; r = 0.803) were highly correlated with ball velocity. These findings suggest that strength training to increase the ball speed of the tennis serve should be performed fast at high angular velocities and planning should focus on the strength of extension, flexion, abduction, adduction and internal rotation.

Normative data in resting and maximum heart rates and a prediction equation for young Tunisian soccer players: a cross-sectional study.

Heart rate (HR) is an important indicator of work intensity during physical activity. Maximum heart rate (MHR) is a physiological measure that is frequently used as a benchmark for maximal exercise intensity. The aim of this study was to establish reference curves for maximum heart rate (MHR) and resting heart rate (RHR) and to develop an estimated equation for Tunisian adolescent footballers. The study involved 801 adolescent players, aged 11 to 18, who belonged to five Tunisian first-division soccer teams. The LMS method was used for smoothing the curves and the multivariate linear regression to develop a prediction equation of MHR. Our results showed that MHR and RHR reference curves decrease with age. The values of the median curves of MHR and RHR ranged from 208.64 bpm (11 years) to 196.93 (18 years) and 73.86 (11 years) to 63.64 (18 years), respectively. The prediction equation obtained from the model was MHR= 225.08 - 1.55 X Age (years) (R2 = 0.317; P < 0.001; standard error of the estimate (SEE) = 5.22). The comparisons between the estimated values and the measured values have found that our model (- 0.004 ±5.22 bpm) was to be more accurate than two other widely known models. BOX's equation underestimates the measured MHR values by -3.17 ± 5.37 bpm and TANAKA's equation overestimates by + 4.33 ±5.5 bpm. The reference curves can be used by coaches and physical trainers to classify the resting heart rate (RHR) and maximum heart rate (MHR) of each adolescent player, track their evolution over time, and design tailored training programs with specific intensities for Tunisian soccer players.

Concentric Isokinetic Strengthening Program's Impact on Knee Biomechanical Parameters, Physical Performance and Quality of Life in Overweight/Obese Women with Chronic Meniscal Lesions.

Meniscal injuries are one of the most common intra-articular knee injuries. Different treatments are presented depending on the symptoms and duration of meniscus tears, such as arthroscopic partial meniscectomy, physiotherapy, or even pharmacological treatment. The purpose was to investigate the effect of a concentric isokinetic knee muscle strengthening program on strength, joint range of motion, physical performance, quality of life and pain tolerance in overweight/obese women with chronic meniscal lesions. Twenty-four overweight/obese women were randomized into two groups. A control group (CG) performed a usual rehabilitation program plus isokinetic muscle strengthening (IMS) in the continuous passive motion mode and measured with an isokinetic dynamometer. An experimental group (EG) performed the same program in combination with IMS in the isokinetic active mode. The peak torque of the knee extensors (PTE) and flexors (PTF), sit-to-stand test, stair climb test, joint amplitude, heel-to-buttock distance, Thessaly test, KOOS questionnaire of pain and quality of life were measured pre- and post-protocol. After the intervention, the sit-stand number for both groups was significantly higher (p < 0.001) and the time to climb stairs was significantly reduced for the EG (p < 0.001). A significant improvement in joint range of motion, life quality (p < 0.001), relief in knee pain (p < 0.001) and in the post-program evaluation at the EG (p < 0.05) was noted. There was no significant difference in PTE and PTF between groups at 60°/s and 180°/s. The IMS in the active mode could be an effective therapeutic modality in managing middle-aged patients suffering from a degenerative meniscal tear.

A Deep Learning Neural Network to Classify Obesity Risk in Portuguese Adolescents Based on Physical Fitness Levels and Body Mass Index Percentiles: Insights for National Health Policies.

The increasing prevalence of overweight and obesity among adults is a risk factor for many chronic diseases and death. In addition, obesity among children and adolescents has reached unprecedented levels and studies show that obese children and adolescents are more likely to become obese adults. Therefore, both the prevention and treatment of obesity in adolescents are critical. This study aimed to develop an artificial intelligence (AI) neural network (NNET) model that identifies the risk of obesity in Portuguese adolescents based on their body mass index (BMI) percentiles and levels of physical fitness. Using datasets from the FITescola® project, 654 adolescents aged between 10-19 years old, male: 334 (51%), female: n = 320 (49%), age 13.8 ± 2 years old, were selected to participate in a cross-sectional observational study. Physical fitness variables, age, and sex were used to identify the risk of obesity. The NNET had good accuracy (75%) and performance validation through the Receiver Operating Characteristic using the Area Under the Curve (ROC AUC = 64%) in identifying the risk of obesity in Portuguese adolescents based on the BMI percentiles. Correlations of moderate effect size were perceived for aerobic fitness (AF), upper limbs strength (ULS), and sprint time (ST), showing that some physical fitness variables contributed to the obesity risk of the adolescents. Our NNET presented a good accuracy (75%) and was validated with the K-Folds Cross-Validation (K-Folds CV) with good accuracy (71%) and ROC AUC (66%). According to the NNET, there was an increased risk of obesity linked to low physical fitness in Portuguese teenagers.

Obesity Status and Physical Fitness Levels in Male and Female Portuguese Adolescents: A Two-Way Multivariate Analysis.

Obesity and decreasing fitness levels among the youth are growing concerns in Portugal, similar to other developed countries, with implications for health and psychomotor development. Understanding the influence of health determinants such as sex and age are crucial for developing effective public health strategies. This study aimed to analyze the association between sex and chronological age with obesity status and physical fitness in Portuguese adolescents. A total of 170 adolescents (85 males and 85 females) were evaluated for body mass index, abdominal adiposity, aerobic fitness, abdominal resistance, upper limb resistance, lower limb power, and maximal running speed in a 40 m sprint using the FITescola® physical fitness battery, a Portuguese government initiative. The general model, analyzed using Pillai's trace, showed a significant effect of age and sex on body mass index, abdominal circumference, aerobic fitness, abdominal resistance, upper limb resistance, lower limb power, and maximal running speed (V = 0.99, F (7) = 10,916.4, p < 0.001, partial η2, sex = 0.22; age = 0.43, sex and age interaction = 0.10). Boys had higher physical fitness levels than girls in most tests, but both sex groups had a significantly higher proportion of non-fit adolescents, with boys showing the highest number of participants classified as non-fit.

A Randomized Trial of a Swimming-Based Alternative Treatment for Children with Attention Deficit Hyperactivity Disorder.

Attention deficit hyperactivity disorder (ADHD) is considered a highly prevalent neurodevelopmental childhood disorder extending from ages 1−2 to 12−13, associated with impairment across multiple domains, including social, emotional, and cognitive functioning. Little is known about alternative treatments for this disorder. Interest has grown in physical activity as a potential intervention for rehabilitating children with ADHD. This study aimed to investigate the impact of adapted swimming activity on cognitive functions, academic performance, and related behavior of Tunisian children with ADHD. The study was conducted on school children aged 9 to 12 years (n = 40, 5 female and 35 male) diagnosed with ADHD. They were randomly assigned to an experimental group (exercise intervention) or the control group. The Hayling test was used to assess cognitive performance, the Children Behavior Check List (CBCL) was used to assess ADHD-related behavior, and the change in reading and numeracy proficiency was assessed pre- and post-intervention. After 12 weeks of the intervention, the results revealed that there were significant improvements in behavior (p < 0.001), inhibition process (p < 0.001), and academic performance (p < 0.001) in the experimental group compared with the control group. These findings suggest that adapted swimming activity may have positive implications for cognitive function, behavior, and academic performance. This research may provide preliminary support for alternative therapeutic interventions that could be used by practitioners. Moreover, the results support active practice of recreational physical activities as a strategy to support children in overcoming ADHD deficiencies.

Rehabilitation of ADHD children by sport intervention: a Tunisian experience.

INTRODUCTION: Childhood attention-deficit/hyperactivity disorder is associated with impairment across multiple domains, including social, familial, emotional and academic functioning. Available therapies, and in particular medical treatment, fail to produce improvement in this impairment. In this context, interest has grown in physical activity and exercise as potential interventions for the treatment of children with ADHD. AIM: The present study investigates the effect of a recreational swimming program on cognitives functions on Tunisian children with attention deficit hyperactivity disorder (ADHD). METHODS: The study recruited school children aged 9 to 12 years (n total = 40) with diagnosis of ADHD. They were randomly assigned into exercise or control groups. Neuropsychological tasks; the complex figure of Rey (ROCF), the stroop test and the Hayling test were assessed before and after the exercise program. RESULTS: The results indicates that there were significant improvements in memory accuracy (p=0,000), selective attention (p=0,000), and inhibition process (p=0,000), in experimental group compared with the control group after the intervention. In the post-program, children experienced an overall shortening of task execution times with fewer errors of omissions. They also made fewer errors in interference situations, signaling better cognitive functioning. Conclusion These findings suggest that a recreational swimming program may have positive implications for cognitive function and may provide preliminary support for alternative therapeutic interventions that can be used by researchers, parents, educators, and clinicians and they support that  reinforcement approved by recreational program can normalize  cognitive deficiencies in children with ADHD.