Journal of Sports Medicine and Physical Fitness最新文献

Background: The current work aimed to describe and compare the cortisol and insulin concentrations behavior and rate of perceived exertion (RPE) during a 115 km ultramarathon race.

Methods: Nine ultrarunners (eight males) were evaluated six times (0, 37, 60, 76, 89 and 115 km). At each moment, saliva samples (for cortisol and insulin assessment) and RPE (CR10 scale) were collected. Statistical analysis included correlation, one-way repeated measure ANOVA, and Statistical Parametric Mapping to define discrete and continues changes and compare cortisol, insulin and RPE profiles.

Results: Our main findings revealed an early peak in cortisol and RPE, accompanied by a decline in insulin responses (402±49 min of the race, P<0.05). Cortisol and insulin only showed magnitude differences with inverse behaviors until ~6% (7 km) of the ultramarathon duration. Cortisol and RPE presented similar behaviors, rising from the beginning of the race and remaining elevated throughout the race (η²=0.91 and η²=1.0, P<0.001). Insulin levels decreased when the race started, remaining below 60% of baseline values from the midpoint to the end of the race (P=0.04).

Conclusions: The study showed an imbalance in the catabolic/anabolic hormone profile during an ultramarathon race, with a prominence in catabolic state. It should be considered in the ultramarathon races preparation and participation due to its possible detrimental effect on the athlete's health.

We report the case of an athlete who, despite facing the challenges of laryngectomy, underwent a comprehensive cardiopulmonary exercise test to assess both his ability to participate in sports and his cardiopulmonary fitness. We not only highlight the individualized approach to sports assessment in a challenging medical context but also emphasize the feasibility of employing cardiopulmonary testing in evaluating subjects in unusual settings.

The recent advancement of computational systems provides fast information exchange and the collection of large amounts of data. Growing number of those systems allow for effective processing of huge amounts of information, utilizing advanced algorithms that are called artificial intelligence (AI). AI has been used for many years, and the number of its applications is growing in various areas. Such solutions are also being developed increasingly in medicine, including orthopedics and radiology, to support the diagnostic and therapeutic processes. Progress in this area is particularly targeted at the skeletal sites that most often require intervention, such as the hip or knee area, with modest interest in the ankle joint. The ankle is one of the most complicated human joints, and therapeutic procedures for its treatment are relatively common. One of the solutions used in the event of serious ankle joint damage is arthroplasty. This review summarizes the current state of AI applications for the diagnosis and therapy of the ankle joint, focusing on trends and achievements in ankle joint arthroplasty and contemporary orthopedic AI solutions. Ideas from other fields of medical diagnostics or orthopedic surgery that may be utilized in the diagnosis and treatment of ankle joint are also discussed.

Background: The study aimed to try to determine whether there are differences in performance analysis in handball matches won and lost, in Pre-COVID-19, COVID-19, and Post-COVID-19 seasons, taking into account the venue of the match.

Methods: The material was the official statistics of 493 men's handball matches of PGNiG Superliga Ltd. For comparisons between independent variables, the Mann-Whitney U Test and the Kruskal-Wallis Test were used. A Chi-square Test was used to determine the distribution of the number of games won and lost.

Results: The analyses conducted indicate higher values in matches won than in matches lost (P=0.00) for the variables: numbers of goals scored, accurate throws, 6 meters goals, fast breaks, fast break goals, and throwing efficiency: all throws, 9 meters, 6 meters, and goalkeeper efficiency. In losing matches teams lost have a higher number of goals defeated (P=0.00) and executed a higher number of missed throws (P=0.00) than in winning matches Effect size of the differences is large. The results show a higher number of matches won in home matches than away in the Pre-COVID-19 season (P=0.0001).

Conclusions: During the three seasons, the number of throws and goals from 9 meters decreases, while the number of goals from 6 meters increases. In sports training, measures should be taken to improve and increase the effectiveness of actions that affect winning the match. The results indicate the need to shape defensive actions that prevent goals from being scored in situations that differentiate the match's outcome.

Background: This study aimed to elucidate the effectiveness of holding isometric muscle action (HIMA) by examining its impact on vertical jump enhancement due to sex and the presence of the stretch-shortening cycle (SSC) in subsequent jump tasks.

Methods: The sample was 63 men and 42 women aged 20-27, engaged in continuous strength training for over two years at least, without musculoskeletal injuries in the past six months, divided into experimental (EXP) and control (CON) groups for countermovement jump (CMJ) and squat jump (SQ) tests considering sex. Conditioning activity (CA) involved three sets of four seconds of full-back squats at 70% 1RM for the experimental group. Jump heights for CMJ and SJ were measured, and absolute (baseline-best) and relative (%) changes were analyzed. For statistical analysis were made with Three-Way ANOVA and Tukey-Kramer post-hoc tests to evaluate jump performance differences.

Results: EXP achieved more gains than control in SQ for both sexes, and both measurement approaches (P<0.05), yet no sex differences in gains were found (P>0.05). Absolute CMJ improvements were significant in experimental men versus control (P<0.05), but relative gains were not (P>0.05). SSC presence did not differentiate SQ and CMJ improvements according to sex (P>0.05); however, the effect size was large <0.80.

Conclusions: The utility of HIMA protocol as a CA has proven to be effective in improving jump performance despite sex or SSC involvement in subsequent tasks. This study showcases the adaptability of the PAPE protocol based on isometric full-back squats with submaximal load, confirming its effectiveness in enhancing jump performance in various settings.

Background: Padel is a sport that requires a combination of physical and technical skills. Fatigue is a major modulator of padel players' performance. The aim of this study was to analyze the changes in neuromuscular performance and perceived effort among high-level padel players.

Methods: Countermovement jump and handgrip strength of 58 participants (men: N.=38 age = 28.3±7.05 years, height = 178.9±8.41 cm; body mass = 75.25±8.2 kg. women: N.=21, age = 23.07±4.6 years, height = 163.86±10.34 cm; body mass = 59.9±6.13 kg) were assessed pre- and post-match in 43 official matches during the Padel Master 2021 of the Andalusian Padel Federation. Additionally, the Rating of Perceived Exertion (RPE) Scale was used to assess players' subjective perception of effort after each match.

Results: Players experienced significant increases in postmatch jump height, with no changes in handgrip strength. Moreover, changes in jump height were greater in male players after the match when compared to their female counterparts, but the match duration was not determinant when comparing CMJ or handgrip between 2-sets and 3-sets matches. Finally, players reported a higher RPE after longer matches, but perceived effort was not different between sexes.

Conclusions: These findings suggest that the internal load generated during competitive padel matches is insufficient to cause a declination in performance of the studied variables. It is also concluded that players' warm-up routines could be optimized to enhance neuromuscular performance at the start of matches.

Background: Outdoor exercise often proceeds despite rain and wind in cool conditions. The aim of this study was to investigate the effects of rain with wind on physiological responses during running exercise at 70% V̇O2max in cool conditions.

Methods: Eleven healthy men exercised on a treadmill at 70% V̇O2max intensity for 60 min under conditions of 10 mm/h rain and 3 m/sec wind (RW) or not (CON) at 10°C in a climatic chamber able to simulate various temperature, humidity, rain, and wind conditions. Body temperature, expired air, and blood samples were measured at rest and exercise.

Results: Rectal temperature, mean weighted skin temperature, and thermal sensation were all significantly lower in RW than in CON during exercise (all P<0.05). Oxygen uptake was significantly higher in RW than in CON during exercise (all P<0.05). Participants' rating of perceived exertion was significantly higher in RW than in CON at 50 and 60 min (P<0.05). Respiratory exchange ratio was significantly higher in RW than in CON at 10, 20, and 40 min. Plasma lactate concentration and plasma norepinephrine levels were significantly higher in RW than in CON during exercise (both P<0.05).

Conclusions: Rain with wind intensified body heat loss, and energy expenditure and carbohydrate oxidation increased as the body cooled. These conditions may decrease exercise performance.

Background: Studies evaluating alterations in cardiac biomarkers in rapid sport-associated weight loss (RWL) and high-intensity sport-specific training (HISST) are lacking. This pilot study aimed to examine the effects of RWL and HISST on heart rate, blood pressure, cardiac biomarkers, and left ventricular systolic function. Nine elite male judokas participated in the presented survey.

Methods: The athletes underwent a baseline assessment and two testing protocols, the first phase with RWL where they had to lose 5% of their body weight simultaneously with HISST, and the second phase after 7 days, in which only HISST was performed. Participants underwent electrocardiogram, biomarker, and transthoracic echocardiogram evaluation after each phase.

Results: In the first phase (RWL and HISST) athletes, heart rate increased significantly, 58.11 (7.78) versus 79 (9.25), P=0.001; as well as cardiac biomarkers: lactate dehydrogenase isoenzyme 175.33 (31.22) vs. 238.56 (56), P=0.003; aspartate aminotransferase 16.56 (4.61) vs. 29 (9.96), P=0.027; creatine kinase isoenzyme-MB 13 (11.5;24) vs. 29.11 (10.05), P=0.004; and high sensitivity cardiac troponin 10 (0) vs. 14.49 (6.4), P=0.045. In the second phase, only HISST was associated with a significant increase in the alanine aminotransferase isoenzyme, 37.78 (11.22) vs. 26 (8.03), P=0.024, together with creatine kinase 472 (185;654) vs. 166.88 (56.57), P=0.01, compared to the initial measurement.

Conclusions: RWL combined with HISST produced significant alterations in cardiac biomarkers without impairment of left ventricular systolic function.

Background: The purpose of this study was to investigate the effects of caffeinated chewing gum on female softball pitching and hitting performance in trained female softball fielders and pitchers.

Methods: Twenty-four trained female softball players (10 pitchers and 14 fielders) were divided into a caffeine chewing gum trial (CAF) or a placebo trial (PLA) in a single-blind, randomized, crossover experimental design. Two pieces of gum containing 100 mg of caffeine (CAF) or without caffeine (PLA) were chewed for 10 minutes and then spit out, followed by a 15-minute warm-up. The physical tests included grip strength and countermovement jump (CMJ). The softball-specific tests included pitching or hitting. The two trials were separated by seven days.

Results: The CAF trial had significantly higher grip strength than the PAL trial in fielder (P=0.032, Cohen's d=0.29) and pitcher (P=0.016, Cohen's d=0.33). The height of CMJ in fielders was significantly higher in the CAF trial than in the PLA trial (P=0.015, Cohen's d=0.65) but not in pitchers (P=0.596, Cohen's d=0.15). The fielder's average and maximum batting exit speeds were significantly higher in the CAF trial than in the PLA trial (P<0.05). The average and max fastball speeds of the CAF trial were significantly higher than that of the PLA trial in pitchers (P<0.05).

Conclusions: The study showed that chewing gum containing two pieces of gum containing 100 mg of caffeine effectively improved female softball fielder's batting performance and pitcher's pitching performance.