Endurance Capacity Research Articles

STUDY ON THE INFLUENCE OF INJECTION MOLDING PARAMETERS ON THE WARPAGE AND SHRINKAGE IN HOT RUNNER SYSTEM MOLD

The good combination of injection molding parameters (IMP) will make high quality product by elimination of defects occurred during injection molding process such as warpage and shrinkage. This paper investigates influence of IMPs on shrinkage and warpage on injection molding process using hot runner system. Taguchi method and ANOVA analysis are used to optimize the IMPs including melt temperature, filling time, injection pressure, packing pressure, coolant inlet temperature, cooling time, and flow rate. The analysis and simulation processes were done by using a Moldflow software. The plastic material is acrylonitrile butadiene styrene (ABS) with some features of the dimensional stability, chemical endurance, and simple processing capacity. The results show that melt temperature and coolant temperature are the main factors affecting the warpage with 66.67% of melt temperature and 15.59% of cooling temperature. The melt temperature and packing pressure are the main factors affecting the shrinkage with 74.62% of melt temperature and 19.46% of packing pressure. The optimal IMP is retested with warpage defect reduced 16.6% and shrinkage decreased of about 2.45% after optimization.

33-OR: Epigenetic Reader BRD4 Directs Fast-Twitch Myofiber Gene Programs Influencing Skeletal Muscle Endurance Capacity and Systemic Glucose Homeostasis

Skeletal myofibers exhibit remarkable diversity and plasticity in contractile and metabolic functions and play a key role in controlling systemic metabolism. Previous studies of muscle fiber-type switching have centered on the specification of slow-twitch myofibers. However, mechanisms that drive fast-twitch myofibers formation remain unclear. Here, we showed that BRD4, an epigenetic reader enriched in fast myofibers, plays a critical role in controlling fast-twitch myofiber identity as well as systemic glucose homeostasis. BRD4 levels are associated with fast-twitch myofiber gene expression in human muscle. Skeletal muscle-specific ablation of BRD4 in mice (Brd4f/fHSA-Cre, BRD4 mKO) resulted in downregulation of the fast-twitch myofiber gene program, increased number (~100%) of type I myofibers and mitochondrial oxidative capacity. This led to enhanced muscle endurance capacity. In adult mice, acute and inducible BRD4 deletion using a tamoxifen-inducible Cre elicited a similar fast-to-slow fiber type switch in muscle. Mechanically, genome-wide ChIP-seq and mRNA-seq analyses revealed that BRD4 directly binds to and activates transcriptional of fast-twitch myofiber genes through cooperating with MEF2. Furthermore, mice lacking muscle BRD4 were protected against high-fat-diet (HFD)-induced obesity, glucose intolerance and insulin resistance. HFD-fed BRD4 mKO mice had significantly less fat mass (∼50%) compared with HFD-fed WT controls. Histological and biochemical measurements confirmed a pronounced (~60%) decrease in fat deposition in BRD4 mKO livers. Thus, our results uncover a previously unrecognized mechanism underlying the determination of fast-twitch myofiber and provide new therapeutic opportunities for driving muscle fiber-type switch to combat metabolic diseases. Disclosure Z.Zhou: None. L.Liu: None. Z.Xu: None. T.Fu: None. L.Yang: None. M.Yan: None. Z.Gan: None.

Mitral valve prolapse and physical performance in Asian military males: The CHIEF Heart study

ABSTRACT The impact of mitral valve prolapse (MVP) and mitral regurgitation (MR) on physical performance has not been examined. Of 1,808 physically fit Asian military males, we compared the physical fitness between 62 subjects with MVP (MVP(+)) and 1,311 age- and anthropometrics-matched controls from the 1,746 participants without MVP (MVP(-)). MVP and MR grade were defined based on the American Society of Echocardiography criteria. Aerobic endurance capacity was evaluated by a 3000-m run and muscular endurance capacity was separately evaluated by 2-min sit-ups and 2-min push-ups. Analysis of covariance was used to determine the difference between groups. As compared to the MVP(-), the MVP(+) completed the 3000-m run test faster (839.2 ± 65.3 sec vs. 866.6 ± 86.8 sec, p = 0.019), but did fewer push-ups (41.3 ± 3.92 vs. 48.0 ± 10.1, p = 0.02) and similar sit-ups within 2 min. Of the MVP(+), those with any MR (trivial, mild or moderate) completed the 3000-m run test faster than those without MR (830.6 ± 61.7 sec vs. 877.2 ± 61.7 sec, p = 0.02). Our findings suggest that in physically active Asian military males, the MVP(+) may have greater aerobic endurance capacity but lower muscular endurance capacity than the MVP(-). The presence of MR may play a role for the MVP(+) to have greater aerobic endurance capacity.

Effects Of Circuit Training And Battle Rope Training On Cardio Respiratory Endurance Of School Girls

The purpose of the present study was to find out the effects of circuit training and battle rope training on cardio respiratory endurance of school girls. To achieve the purpose of the study thirty school girls from M. Deivanai Achi Government Girls Higher Secondary School, Paganeri, Sivaganga District, Tamilnadu were selected as subjects. The selected subjects’ age ranged from 11 to 13 years. The selected subjects were equally divided into three groups, i.e. two experimental groups and one control group. The experimental group-1 was allotted to circuit training (CT); the experimental group-2 was allotted for battle rope training (BRT) and group-3 acted as control group (CG). The cardio respiratory endurance was chosen as a dependent variable; it was tested by 9 minutes run/walk test. The test was taken before and after the training interventions. Analysis of covariance (ANCOVA) was used to analyze the significant difference, if any among the groups. In order to find out superiority effect among the groups, the Scheff’s Post Hoc test was used. The level of significance was 0.05. After the six weeks training interventions the experimental groups improved the capacity of cardio respiratory endurance. The best improvement was noticed in circuit training.

The effects of low and normal dose ice slurry ingestion on endurance capacity and intestinal epithelial injury in the heat.

Compare the effects of ice slurry ingestion at low and normal doses on endurance capacity and exertional heat stress-induced gastrointestinal perturbations. Randomised, cross-over design. Twelve physically active males completed four treadmill running trials, ingesting ice slurry (ICE) or ambient drink (AMB) at 2 g·kg-1 (Normal; N) or 1 g·kg-1 (Low; L) doses every 15-min during exercise and 8 g·kg-1 (N) or 4 g·kg-1 (L) pre- and post-exercise. Pre-, during and post-exercise serum intestinal fatty-acid binding protein ([I-FABP]) and lipopolysaccharide ([LPS]) concentrations were determined. Pre-exercise gastrointestinal temperature (Tgi) was lower in L + ICE than L + AMB (p < 0.05), N + ICE than N + AMB (p < 0.001) and N + ICE than L + ICE (p < 0.001). Higher rate of Tgi rise (p < 0.05) and lower estimated sweat rate (p < 0.001) were observed in N + ICE than N + AMB. Rate of Tgi rise was similar at low dose (p = 0.113) despite a lower estimated sweat rate in L + ICE than L+AMB (p < 0.01). Time-to-exhaustion was longer in L + ICE than L + AMB (p < 0.05), but similar between N + ICE and N + AMB (p = 0.142) and L + ICE and N + ICE (p = 0.766). [I-FABP] and [LPS] were similar (p > 0.05). L + ICE elicited a lower heat dissipation compensatory effect with similar endurance capacity as N + ICE. Ice slurry conferred no protection against exertional heat stress-induced gastrointestinal perturbations.

Effects of Spirulina on Some Oxidative Stress Parameters and Endurance Capacity in Regular and Strenuous Exercises

Effects of Spirulina on Some Oxidative Stress Parameters and Endurance Capacity in Regular and Strenuous Exercises

Effects of Nutrition Interventions on Athletic Performance in Soccer Players: A Systematic Review.

More than 270 million participants and 128,893 professional players play soccer. Although UEFA recommendations for nutrition in elite football exist, implementing these guidelines among professional and semiprofessional soccer players remains suboptimal, emphasizing the need for targeted and individualized nutritional strategies to improve adherence to established recommendations. We conducted a comprehensive search in PubMed, Scopus, Web of Science, and clinical trial registers. Inclusion criteria focused on professional or semiprofessional soccer players, nutrition or diet interventions, performance improvement outcomes, and randomized clinical trial study types. We assessed quality using the Risk of Bias 2 (RoB 2) tool. We identified 16 eligible articles involving 310 participants. No nutritional interventions during the recovery period effectively improved recovery. However, several performance-based interventions showed positive effects, such as tart cherry supplementation, raw pistachio nut kernels, bicarbonate and mineral ingestion, creatine supplementation, betaine consumption, symbiotic supplements, and a high-carbohydrate diet. These interventions influenced various aspects of soccer performance, including endurance, speed, agility, strength, power, explosiveness, and anaerobic capacity. Specific strategies, such as solutions with bicarbonate and minerals, high carbohydrate diets, and supplements like creatine, betaine, and tart cherry, can enhance the performance of professional soccer players. These targeted nutritional interventions may help optimize performance and provide the competitive edge required in professional soccer. We did not find any dietary interventions that could enhance recovery.

Функціональні можливості серцево-судинної системи та стресостійкість осіб із різною теплочутливістю

Global warming affects people’s daily life, reduces endurance and work capacity. The purpose of our study is to investigate the functional capabilities of the circulatory system, adaptation potential and stress resistance of individuals with different heat sensitivity. To evaluate the activity of the cardiovascular system, an echocardiographic examination was performed. The reserve capabilities of the heart and the economy of its work were determined using the Robinson index and the Roufier test. Resistance to hypoxia was determined using the Stange and Genchi tests. The degree of oxygen assimilation was evaluated according to the values of maximum oxygen consumption. Cardiorespiratory fitness was determined based on the results of the Rufier test. Adaptation potential was established according to Baevsky’s method. Stress resistance was assessed by determining the response index of the cardiovascular system to psycho-emotional stress. It was established that in people with lower heat sensitivity, the activity of the cardiovascular system is more optimal and more economical and its reserve capacity is greater, compared to higher sensitivity individuals, in which the intensity of its work in an uneconomical mode is increased and the reserve potential is limited. Shorter breath retention time on inhalation and exhalation, respectively, in persons with higher sensitivity to heat indicates a worse oxygen supply to the body. Also, they have a poor ability to absorb oxygen and lower cardiorespiratory efficiency. The predominance of stress adaptation mechanisms and lower stress resistance were also revealed. Thus, our results show that individuals with a higher sensitivity to heat are particularly vulnerable to the negative effects of global warming, which should be taken into account for the prevention of cardiovascular and heat diseases in them in the future.

The Efficient Synthesis and Anti-Fatigue Activity Evaluation of Macamides: The Unique Bioactive Compounds in Maca.

Macamides are a class of amide alkaloids that are only found in maca and are widely considered to be its bioactive marker compounds. More than thirty macamide monomers have been identified in recent years; however, it is difficult to obtain a single macamide monomer from the maca plant because of their similar structures and characteristics. We used the carbodiimide condensation method (CCM) to efficiently synthesize five typical macamides, including N-benzyl-hexadecanamide (NBH), N-benzyl-9Z,12Z,15Z-octadecenamide, N-(3-methoxybenzyl)-9Z,12Z-octadecenamide, N-benzyl-9Z,12Z-octadecenamide, and N-(3-methoxybenzyl)-9Z,12Z,15Z-octadecadienamide. All the synthesized macamides were purified by a one-step HPLC with a purity of more than 95%. NBH is the most abundant macamide monomer in natural maca, and it was selected to evaluate the anti-fatigue effects of macamides. The results indicated that NBH could enhance the endurance capacity of mice by increasing liver glycogen levels and decreasing blood urea nitrogen, lactate dehydrogenase, blood ammonia, and blood lactic acid levels. Macamides might be the active substances that give maca its anti-fatigue active function.

Gait Training with Functional Electrical Stimulation Improves Mobility in People Post-Stroke

(1) Background: Stroke is one of the leading causes of disability. To identify the best treatment strategies for people with stroke (PwS), the aim of the current study was to compare the effects of training on a treadmill with functional electrical stimulation (TT-FES) with training on a treadmill (TT), and to analyze the effects of sequence of training on mobility and the parameters of walking ability. (2) Methods: Prospective, longitudinal, randomized and crossover study, in which 28 PwS were distributed into groups, namely the A-B Group (TT-FES followed by TT) and B-A Group (TT followed by TT-FES), using the foot drop stimulator, and were measured with functional tests. (3) Results: We found improved mobility, balance, non-paretic limb coordination, and endurance only in the group that started with TT-FES. However, sensorimotor function improved regardless of the order of training, and paretic limb coordination only improved in the B-A Group, but after TT-FES. These data indicate that the order of the protocols changed the results. (4) Conclusions: Although biomechanical evaluation methods were not used, which can be considered a limitation, our results showed that TT-FES was superior to isolated training on a treadmill with regard to balance, endurance capacity, and coordination of the non-paretic limb.

Effect of iron-enriched bean-based diet on body weight, exercise performance and iron biomarkers in young adult BALB/c mice

Iron deficiency contributes to the global burden of disease, affecting children, premenopausal women, and population from low-income and middle-income countries. To manage the deficit of iron on diet, biofortified crops can be obtained from conventionally plant-based foods. BIO102 bean is a biofortified crop with higher iron and protein content when compared to conventional beans. Therefore, this study aimed to determine the effect of BIO102 food on body weight, exercise performance, and iron biomarkers in young adult BALB/c mice. To achieve this, 24 BALC/c mice were randomly assigned to each of the following groups (n=6 per group): Control diet (conventional diet 5010 Diet; CTRL), bean-based biofortified diet (BIO102), bean-based non-biofortified diet (NB), and corn-based diet (CD). The following parameters were assessed weekly from baseline to 8 weeks: body weight, food intake, endurance capacity, and limbs strength. Baseline blood glucose and hemoglobin measurements were made at the first, three, and eighth weeks of tail blood, and serum ferritin, hepcidin, C-reactive protein, and testosterone measurements were made at the end of 8 weeks of whole blood.During the initial week of housing (acclimatization), there were no differences among groups on neither food intake nor body weight ( p&gt;0.05) (Figure 1). A significant difference in body weight from the second week of feeding with the natural diets was found (Figure 1). Due to signs of stress after three weeks of feeding, all the groups that took the natural diets, received 1 g of 5010Diet food as supplementation up to the end of the experiment. Both CTRL and BIO102 groups showed higher body weight gain when compared to NB and CD groups. Regarding exercise performance, no significant differences were found among groups (Figure 2). As for the iron biomarkers, no differences were determined for hemoglobin concentration and blood glucose in acclimatization (Figure 3). Interestingly, at three weeks, bean-based diet groups were significant different from CTRL group for Blood glucose concentration ( p&lt;0.05) (Figure 3). Moreover, at 8 weeks, only CD group showed a statically significant increase in ferritin (Table 1). In summary, our results suggest that bean-based biofortified diet (BIO102) has a higher nutritional value than common crops such as conventional beans and corn, when compared with a control diet. This suggestion is because the mice feed with BIO102 diet kept body weight gain like those in CTRL group. In addition, BIO102 reduced fasting blood glucose, maintaining both endurance capacity and strength, as well as biomarkers of iron regulation. This work was funded by the following: Pontificia Universidad Javeriana Cali-Colombia, El Centro Internacional de Agricultura Tropical (CIAT) y la Fundación Banco de la República. This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Increased nitric oxide-soluble guanylyl cyclase signaling improves endurance capacity and contracting skeletal muscle oxygenation in healthy female rats

Introduction: During exercise skeletal muscle blood flow and O2 delivery (Q̇O2) as well as mitochondrial oxygen uptake (V̇O2) are regulated, in part, by nitric oxide (NO)-soluble guanylyl cyclase (sGC) signaling. Exercise-induced metabolic adaptations within skeletal muscle lead to a higher Q̇O2-V̇O2 ratio (measured as increased interstitial partial pressure of O2, PO2 is), which is driven partly via increases in NO bioavailability. The sGC activator BAY 60-2770 augments downstream NO signaling by targeting the heme-free sGC enzyme, which constitutes 20-60% of sGC in healthy smooth muscle cells. We tested the hypotheses that sGC activator BAY 60-2770 administration would increase skeletal muscle oxygenation (spinotrapezius PO2 is) and enhance endurance capacity. Methods: Healthy female Sprague-Dawley rats (n=6) performed a baseline time-to-exhaustion (TTE) exercise protocol and were then randomly assigned to vehicle (V) or sGC activator (sGC) groups. sGC rats were administered 0.3 mg/kg b.i.d for five days via oral gavage. Following the dosing regimen, repeated TTE testing determined running endurance capacity on a motor-driven treadmill. On a subsequent day, the PO2 is at rest and its temporal profile following the onset of 1 Hz twitch contractions in the spinotrapezius muscle were measured using phosphorescence quenching under pentobarbital anesthesia. Results: sGC rats evidenced a 34% increase in TTE (p &lt; 0.05) compared to V rats. There was no statistical difference in arterial blood gases and pH or heart rate and mean arterial pressure between groups during anesthesia (p &gt; 0.05). Phosphorescence quenching revealed a significant increase in PO2 is at rest and during contractions (p &lt; 0.05) in sGC versus V rats. Conclusions: These findings demonstrate that increasing downstream NO signaling via augmented sGC activity has the potential to improve endurance exercise capacity and skeletal muscle oxygenation at rest and during contractions in female rats. Further studies will focus on increasing the sample size to assess the robustness of these observations and investigate whether there is any pertinent sexual dimorphism in sGC signaling. We will also resolve corollary molecular signaling pathways that might be upregulated by chronic sGC activation which may positively impact skeletal muscle contractile function and exercise performance. This work was supported, in part, by the National Institute of Aging (1 R15 AG 078060) and a SMILE Award from Kansas State College of Veterinary Medicine. This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Establishing Reference Data for Fitness Assessment of Law Enforcement Officers Using a Qualitative Systematic Review.

Physical fitness tests are a standard means of evaluating the competence of police officers. This qualitative review aims (i) to document, compare, and examine the reference values available in the current literature regarding fitness tests for Law Enforcement Officers (LEOs), and (ii) to define reference values for the most used fitness tests to assess and predict police officer performance. A total of 1879 records were collected for review from two major literature databases, PubMed and ScienceDirect. After applying our exclusion criteria, a total of 19 studies were considered. All studies demonstrated acceptable methodological quality in fitness assessment, and the most used components were muscle strength, muscular endurance, muscle power, aerobic and anaerobic capacity, flexibility, and agility. This review provides (i) a methodological definition for the physical fitness assessment that helps select the most used fitness tests, (ii) a standardised methodology for establishing reference data for fitness tests appropriate for LEOs; and (iii) aggregate reference values for selected fitness tests. This may improve selection and retention procedures, considering that this group performs its duties in an environment and under conditions that differ from those of other occupational groups. Complementarily, this qualitative review also provides a foundation for developing effective interventions to improve each aspect of fitness testing for police officers.

Aerobic exercise training-induced alteration of gut microbiota composition affects endurance capacity.

This study aimed to clarify whether aerobic exercise training-induced alterations in the gut microbiota affect physiological adaptation with endurance exercise capacity. In study 1, ICR mice were randomly divided into three groups: vehicle intake + sedentary (V+S), vehicle intake + exercise training (V+Ex) and antibiotic intake + exercise training (AB+Ex). In the exercise training groups, treadmill running was performed for 8weeks. During the exercise training intervention, the antibiotic-intake group freely drank water containing antibiotics. In study 2, ICR mice were randomly divided into three groups: Sham, transplantation of caecum microbiota from sedentary mice (Sed-CMT) and exercise training mice (Ex-CMT). In study 1, the treadmill running time to exhaustion, an index of maximal aerobic capacity, after aerobic exercise training in the V+Ex group was significantly longer than that in the V+S and AB+Ex groups. Gastrocnemius muscle citrate synthase (CS) activity and PGC-1α protein levels in the V+Ex group were significantly higher than in the V+S and AB+Ex groups. The bacterial Erysipelotrichaceae and Alcaligenaceae families were positively correlated with treadmill running time to exhaustion. In study 2, the treadmill running time to exhaustion after transplantation was significantly higher in the Ex-CMT group than in the Sham and Sed-CMT groups. Furthermore, CS activity and PGC-1α protein levels in the gastrocnemius muscle were significantly higher in the Ex-CMT group than in the Sham and Sed-CMT groups. Thus, gut microbiota altered by aerobic exercise training may be involved in the augmentation of endurance capacity and muscle mitochondrial energy metabolism. KEY POINTS: Aerobic exercise training changes gut microbiota composition, and the Erysipelotrichaceae and Alcaligenaceae families were among the altered gut bacteria. The gut microbiota was associated with endurance performance and metabolic regulator levels in skeletal muscle after aerobic exercise training. Continuous antibiotic treatment attenuated the increase in endurance performance, citrate synthase activity and PGC-1α levels in skeletal muscle induced by aerobic exercise training. Gut microbiota transplantation from exercise-trained mice improved endurance performance and metabolic regulator levels in recipient skeletal muscle, despite the absence of aerobic exercise training.

Literature review: nutrition supplementation for muscle fatigue in athletes

The use of natural or conventional-based supplementation has become a popular strategy among athletes seeking to reduce oxidative stress, improve recovery, and enhance athletic performance. This literature review searched four reputable international electronic databases, including PubMed, MedRxiv, Cochrane, and Clinical Trial.gov until December 2021, using Boolean operators with keywords and Mesh methods. The keywords used were "Supplementation", AND "Muscle Fatigue Recovery", AND "Athletes", which yielded 24 articles as study findings. The literature review found that exhaustive exercise can induce a neutrophil antioxidant response by increasing antioxidant enzymes. Nutritional supplements, specifically antioxidant supplements, Branched Chain Amino Acid (BCAA), citrulline, omega-3, and caffeine, have been scientifically proven to reduce oxidative damage, which can block signaling pathways related to muscle hypertrophy. In order to combat muscle fatigue in athletes based on this research (literature review), natural ingredients and synthetic nutritional supplements have been utilized as dietary interventions. This literature review identified numerous natural micronutrients and synthetic supplements used in sports that possess anti-fatigue properties, decrease oxidative stress and enhance athletes' endurance capacity. The effectiveness of nutritional supplements in addressing muscle fatigue may vary based on the various ingredients in the supplements. However, natural-based supplements have become a preferred option among athletes and coaches currently.

Dynamic truck–drone routing problem for scheduled deliveries and on-demand pickups with time-related constraints

The on-demand logistics services have risen continuously with the expansion of e-commerce. Logistics companies face challenges to meet customers’ expectations with high efficiency and reliability at a low cost. Hence, this paper investigates the dynamic truck–drone routing problem with scheduled deliveries and on-demand pickups (D-TDRP-SDOP) for an on-demand logistics system. Trucks and drones are deployed to serve a batch of deterministic deliveries and an uncertain set of pickup requests with deadlines subject to maximum working hour constraints. The drones can serve multiple requests per trip subject to load constraints and endurance capacity restrictions. The service provider aims to maximize the total profits by dynamic reassignment and recourse of the vehicles. We formulate the D-TDRP-SDOP problem as a Markov decision process (MDP) and propose a heuristic solution approach framework, consisting of an offline enhanced construction algorithm (OECA) and a segment-based heuristic, to solve the MDP. The comprehensive numerical experiments demonstrate the effectiveness of the proposed solution approach and the benefits of the model. Our model improves the total profits by 15% by considering on-demand requests, and the drone operations contribute to a 50% improvement in the acceptance rate of dynamic customer requests. Improved drone technology, such as a higher drone speed and a higher battery capacity, can enable the system to serve more on-demand requests and increase the final profits. However, the benefit diminishes when the drone capability reaches a certain threshold.

School-Based Circuit Training Intervention Improves Local Muscular Endurance in Primary School Students: A Randomized Controlled Trial.

This study aimed to explore the effectiveness of a 12-week circuit training program in improving local muscular endurance in normal-weighted primary school students. The study involved a parallel-group randomized trial with 606 primary school boys assigned to an experimental or a control group. The participants underwent a 12-week circuit training program that involved multi-joint, total-body workouts using body weight, resistance bands, and medicine ball exercises. The study measured the participants' local muscular endurance during sit-ups, dynamic trunk extensions on a Roman bench (DTE), and push-ups. After adjusting for the baseline, the treatment-grade interaction was significant for sit-ups (F = 7.74, p < 0.001, ηp2 = 0.04), DTE (F = 6.49, p < 0.001, ηp2 = 0.03), and push-ups (F = 9.22, p < 0.001, ηp2 = 0.05), where the experimental treatment was more beneficial than the control. The treatment effect seemed to vary depending on the individual's baseline local muscle endurance capacity. As the baseline local muscular endurance values increased, the treatment and grade effects became less beneficial. A 12-week circuit training program involving body weight, resistance bands, and medicine ball exercises suits school-based programs and can improve local muscular endurance in normal-weighted primary school boys. The experimental treatment was more effective than the control, and the individual baseline muscular endurance should be considered when designing training programs.

The impact of (Hypoxic) activities in establishing certain particular endurance qualities in basketball players under the age of 18

Basketball is one of the competitive sports that is distinguished by fluctuating motor performance. Due to the tiny size of the basketball court, the numerous motions, the close closeness of the opponent, and the engagement of all team members in offensive and defensive operations. This requires internal physiological adaptations as well as players acquiring specific physical talents and mastering skills. As a result, coaches have to pay close attention to the use of various workouts and technologies that allow the athlete to undergo physiological changes. As a side effect, particular abilities are developed, skills are acquired and mastered, and the capacity to execute with control, fluidity, and great precision is attained. The aim of the study is to construct hypoxic (hypoxic) exercise and to determine the impact of hypoxic (hypoxic) activities on developing specific particular endurance capacities in basketball players under the age of 18. The experimental strategy was chosen by the researcher because it was appropriate for the nature and aims of the study. The research population was drawn from the youth of Al-Hilla Basketball Club (2022-2023), which had a total of (12) players. The purposeful approach was used to choose the primary sample for the study, which was represented by the youth of Al-Hilla Basketball Club in Babil Governorate, who numbered (6) players, and the researcher employed certain current methods and instruments to finish the research. The most essential finding is that hypoxic workouts are extremely helpful in developing exceptional skills. In terms of hypoxic workouts, it favors the development of endurance above strength and speed. The growth of physiological factors influenced the development of exceptional abilities positively. Among the most important recommendations: Need to use hypoxia exercise by coaches and in all sports to save strength and time and achieve training goals the use of hypoxic exercises with other biokinetic skills, the use of hypoxic exercises with advanced players in basketball and other games.

A unified switching dynamic modeling of multi-mode underwater vehicle

Hybrid underwater vehicles have increasingly been deployed in ocean observation and monitoring. This study presents a novel multi-mode underwater vehicle (MUV) motivated by integrating maneuvering efficiency, endurance, and vertical continuous observation capacity. It can switch freely among three operation modes, including vertical diving and floating mode (VDF mode) like the Argo profiling float (APF), steady gliding mode (SG mode) similar to the underwater glider (UG), and propeller-rudder propulsion mode (PRP mode) such as the autonomous underwater vehicle (AUV). The generalized theory of mode switching through extreme pitch angle adjustment is emphasized, mainly to achieve smooth switching between VDF mode and SG mode (or PRP mode) with the critical design principles of the attitude and buoyancy subsystems. Mathematical models describing the motion of three operation modes are developed, particularly considering the actuators’ dynamic characteristics. Simulations are performed to verify the mobility performance of the vehicle, especially considering the influence of actuator dynamics on mode switching. Real-time prototype experiments demonstrate the desired performance of various modes and, in particular, confirm the necessity of the mentioned design criteria for mode switching.

Effect of 12-week sports intervention programme on physical fitness and sports performance in individuals with spinal cord injury

Objectives: Inactivity in individuals with spinal cord injury (SCI) results in low physical fitness, cardiopulmonary endurance and poor quality of life. Sports participation is known to enhance physical fitness. Therefore, the present study evaluated effect of a structured, 12-week MGM Sports Intervention for Sports Intervention Program for SCI (SPISI) on physical fitness and throw-ball performance in individuals with SCI. Materials and Methods: The study was conducted at MGM School of Physiotherapy and Spinal Cord Injury Rehabilitation centre in Navi Mumbai, India. Following ethical approval, 15 individuals with SCI (80% males and 20% females mean age 33.1 ± 7.2 years) were recruited. Upper-extremity explosive power (medicine-ball-throw), agility (t-test), cardiorespiratory endurance (incremental shuttle wheelchair propulsion test) and ball-throwing capacity (maximal-pass test) were evaluated pre- and post-12-week sports intervention programme (SPISI). The protocol involved strength training of upper extremity training at 50% 1 repetition maximum and participation in throw-ball sport. Results: Following training, increase in upper extremity explosive power (11%), cardiopulmonary endurance (5%), agility (8%) and ball-throwing capacity in distance (7%) (P &lt; 0.05) was observed. The large effect size was observed for sports performance (maximal-pass test distance-Cohen’s d 1.261), moderate for cardiorespiratory endurance (incremental wheelchair propulsion test distance Cohen’s d 0.517) and upper extremity explosive power (medicine-ball throw distance 0.593). Increment in all outcome variables was greater than minimal clinically important difference. Conclusion: Sports intervention programme (SPISI) for 12 weeks brought about minimal clinically important difference in upper-extremity explosive power, agility, cardiorespiratory endurance and sport-specific performance and should be included as an integral component of rehabilitation of individuals with SCI.