Journal of Sports Medicine and Physical Fitness最新文献

Background: Evidence on the effectiveness of combined exercise over aerobic exercise alone in lowering blood pressure (BP) remains limited. This study compared the effectiveness of combined aerobic plus resistance training versus aerobic training alone, with both interventions matched for exercise duration.

Methods: This randomized controlled trial included thirty-one female participants eligible for final analysis. Participants were randomly assigned to two groups: 15 to the Control (C) group, which underwent 8 weeks of aerobics, and 16 to the Combined Training (CT) group, which underwent 8 weeks of combined training. Outcome measures included weight, height, Body Mass Index (BMI), systolic and diastolic blood pressure (SBP and DBP), heart rate (HR), mean arterial pressure (MAP), pulse pressure (PP), hand grip strength (HGS), and performance on the 30-second Chair Stand Test (30-s CST). These variables were assessed at baseline and at the end of week 8. Two-way ANOVA followed Tukey post-hoc was applied to analyze changes within and between groups over time. The effect size was calculated using partial eta squared (ηp²).

Results: Baseline characteristics were similar across groups, except for heart rate. Both groups showed significant reductions in SBP and DBP after the intervention ([C: SBP decreased by -7.4±2.2, P=0.00; DBP decreased by -5.1±2.4, P=0.00] [CT: SBP decreased by -6.1±2.1, P<0.01, and DBP decreased by -6.9±2.0, P<0.01]). The reduction in SBP was more pronounced in the C than in the CT (P=0.04), while the reduction in DBP was greater in the CT group (P=0.04). An improvement in the outcome variable is caused by the "group" or "time" effect but not by the effect of "group × time."

Conclusions: Adding resistance training to aerobic exercise enhances the reduction in diastolic blood pressure compared to aerobic exercise alone in prehypertension middle-aged women.

Background: Saliva sampling provides a practical noninvasive way for biological monitoring of steroid hormones but few studies have focused on saliva sex hormones in female athletes, and it is still unknown whether salivary concentrations are an accurate reflection of blood concentrations in this population. The aim of this study was therefore to evaluate the correlation between serum and saliva estradiol (E2) and progesterone (PG) in 10 young female athletes with normal menstrual cycle.

Methods: Thirty blood and saliva samples were taken at rest in a fasting state in order to analyze E2 and PG concentrations, during 3 different hormonal periods: Status 1: low E2 and low PG (end luteal/early follicular); Status 2: high E2 and low PG (end follicular/peri-ovulatory); Status 3: high PG (mid-luteal).

Results: A strong correlation was found between serum and saliva PG (r=0.914, P<0.01), whereas a weaker but still significant relationship was observed between serum and saliva E2 (r=0.755, P<0.01). The most significant correlations obtained for E2 were during Status 2 (r=0.941, P<0.01) and during Status 3 for PG (r=0.817, P<0.01).

Conclusions: Although it remains challenging to produce precise identification with only saliva samples for each menstrual cycle phase, results seem to show that saliva can provide a convenient substitute to serum for sex hormones in female athletes during longitudinal monitoring. This is of particular interest in this population, with the number of female athletes suffering from an altered menstrual cycle, sometimes even during regular menstruation.

Background: To obtain the benefits of exercise as physical inactivity becomes a global concern, managing psychological hurdles to exercise implementation is important. This study examined troublesomeness, motivation, and physiological parameters immediately before exhaustive exercise.

Methods: Thirty-one healthy university students (mean age 19.87±2.21 years, 19 female) performed two conditions on separate days: performing push-ups to exhaustion (PE condition) and performing push-ups of the 30% count of the PE condition (P30 condition). Before the push-ups, the participants sat at rest for 5 minutes and were asked about their psychological states; after the first 2 minutes, PE or P30 conditions to be performed that day were disclosed to prepare them psychologically. During the rest, changes in the heart rate variability (HRV), pupil diameter, and front polar area (FPA) neural activity were measured before and after disclosure.

Results: Troublesomeness and FPA neural activities were significantly higher in the PE than in the P30 (P<0.001, P=0.04, P=0.01). Correlation analysis revealed correlations between motivation and pupil diameter (P=0.002), and negative correlations between total physical activity (TPA) and negative image of exercise (P=0.01).

Conclusions: FPA activity could reflect the psychological hurdle to exhaustive exercise, pupil diameter could reflect the motivational arousal to exercise, and TPA could modulate the psychological hurdle.

Introduction: Chronic low back pain (CLBP) is a prevalent condition causing significant disability worldwide. Traditional treatments often have limited effectiveness, prompting research into alternative, non-invasive interventions. This review examines the impact of unstable footwear on CLBP management, exploring its potential to reduce pain and disability.

Evidence acquisition: We analyzed randomized controlled trials focusing on adults with CLBP. Studies comparing unstable footwear to standard care or conventional footwear were included. Main outcomes measured were pain reduction, functional improvement, and biomechanical changes. Methodological quality was assessed using the PEDro scale.

Evidence synthesis: Five studies met the inclusion criteria, showing a consistent trend towards pain reduction in participants using unstable footwear. Specifically, intervention groups reported significant improvements in pain levels and, in some cases, disability scores compared to control groups. However, findings on functional performance and long-term effects were mixed, with no significant differences in certain studies. Methodological quality varied, with an estimated PEDro score range of 6-7 across the reviewed studies.

Conclusions: Unstable footwear may offer a beneficial non-invasive intervention for individuals with CLBP, contributing to pain reduction and possibly improving disability. Nonetheless, the evidence is tempered by methodological limitations and the need for further research. Future studies should focus on long-term outcomes, larger sample sizes, and clarifying the mechanisms behind the observed benefits. Clinicians should consider unstable footwear as part of a personalized treatment plan for CLBP, keeping abreast of new research to inform their practice.

Background: The aim of this prospective randomized clinical study was to compare the clinical and second-look arthroscopic outcomes of early weight-bearing and delayed weight-bearing rehabilitation protocols following anterior cruciate ligament (ACL) reconstruction with hamstring tendons.

Methods: This prospective study involved 90 patients who underwent ACL reconstruction with hamstring tendons. The patients were randomly assigned to either perform weight-bearing exercises at three weeks postoperatively (group A) or at one week postoperatively (group B). Evaluation of the patients was conducted at 3, 6, and 12 months postoperatively, focusing on knee range of motion, thigh circumference, and knee function assessed using the International Knee Documentation Committee (IKDC) form and Lysholm knee score. Graft evaluation was performed based on tension, tear, and synovial coverage via second-look arthroscopy at least one year after reconstruction.

Results: Group B exhibited significantly greater knee extension and flexion angles at 3 and 6 months compared to group A. IKDC and Lysholm scores were significantly higher in group B at 3 and 6 months. Additionally, the difference in thigh circumference between groups A and B was smaller at all evaluation periods, indicating less muscle atrophy in group B. Furthermore, there was no significant difference in synovial coverage, graft tear, or tension between the two groups based on second-look arthroscopy findings.

Conclusions: This study demonstrates that an early weight-bearing protocol leads to faster recovery of knee joint function and muscle strength, facilitating a quicker return to sports activities. Additionally, there was no significant difference in graft morphology observed at second-look arthroscopy between the two groups at one year postoperative. Therefore, clinicians are encouraged to develop suitable early weight-bearing rehabilitation protocols for patients who have undergone ACL surgery.

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: Hamstring strains may alter the contractile properties of the muscle and affect functional movement. Thus, this study evaluated the association between the hamstring properties and the jump-landing performance in athletes with hamstring strains.

Methods: Sixteen hamstring-injured athletes and 16 healthy controls were recruited. The mechanical properties and contractile function of the hamstring were assessed in both the injured and non-injured legs. The control group was tested only in the matched injured leg. The kinetic outcomes during squat jump (SJ) and countermovement jump (CMJ) tasks were analyzed to evaluate the jump-landing performance.

Results: The injured limb exhibited higher muscle tone (P=0.042) and stiffness (P=0.010), but lower flexibility (P=0.002) and strength (P=0.040) than the control limb. The injured limb showed a poorer jumping performance (P=0.037 for jump height) and landing performance (P=0.011 for landing force and P=0.004 for loading rate) during the CMJ task compared to the control limb. All the hamstring properties showed mild-to-moderate correlations with the jump-landing performance.

Conclusions: Impairments in the muscle properties following hamstring strain impact the jumping and landing performance, leading to degraded sports outcomes in athletes with hamstring injuries. Thus, more attention should be paid to tissue property changes following hamstring strain injuries to develop effective strategies for restoring muscle function and improving sports performance.

Background: Critical swimming velocity (CV) is widely used as an index for setting intensity in endurance training (IT). This study aimed to examine the effects of varying repetitive swimming distances on physiological and stroke parameters during IT at CV.

Methods: Eleven male national-level collegiate swimmers participated in all-out 200 and 400 m front crawl swims to determine the CV. The participants then completed three interval training sets at CV: 5×400 m (400-m IT), 10×200 m (200-m IT), and 20×100 m (100-m IT) interval swims at the CV with rest periods of 60, 30, and 15 s, respectively.

Results: The mean calculated CV value was 1.44±0.07 m/s. Posttest blood lactate concentration was significantly lower during the 100-m IT (3.4±1.9 mmol/L, P<0.05) versus the 400-m IT (6.4±2.6 mmol/L) and 200-m IT (5.3±3.2 mmol/L). Across all tests, heart rate (HR) and rating of perceived exertion (RPE) were significantly higher with longer repetitive swimming distances, while stroke length (SL) was lowest in the 400-m IT (P<0.05). The increases in HR and RPE, as well as the decrease in SL, were statistically significant throughout all training sets (P<0.05).

Conclusions: The findings indicate that longer repetitive swimming distances at CV elicit higher the metabolic, perceptual, and mechanical stimuli. These changes suggest that IT at CV is an effective training condition for enhancing endurance performance.

Background: The opportunity to compare data among players using normative data and benchmarks may represent a helpful tool for coaches to assess the players' physical performance easily and quickly. This study aimed to create normative data and benchmarks that can be exploited to compare professional soccer players' physical capacity competing in the Premier Division Championship (series A).

Methods: Match data from six professional soccer teams competing in the Premier Division championship (Serie A and Italy Cup matches) were collected during the entire season. Players (N.=112) were divided based on the role positioning as follows: forwards and wingers (FW), midfielders (MF), side-backs (SB), and center-backs (CB). All the teams analyzed competed with a 4-3-3 formation, and only players who played for the entire match (85-95 minutes) were considered. The video analysis system STATS SportVU was used to collect the data during official matches. Average metabolic power (AP) was considered to estimate the energy cost. The number of power events (PE), distance (m) covered at more than 25 W/kg (D25), and finally, the distance covered at v>25 km/h (VHS) were considered as high-intensity assessments. Standardized T-scores (scaled from 0 to 100) were calculated for each role and variable.

Results: T-score data was used to create performance bands combined with qualitative description (ranging from extremely poor to excellent), and a traffic light system approach was implemented to simplify the data's interpretation.

Conclusions: The results could be used to compare different athletes' performance quickly and effectively, to detect symptoms of overtraining, and to give helpful insights to coaches on what the training should be focused on.

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.