Test-retest reliability of knee extensors endurance test with elastic resistance.

BACKGROUND: Reliable clinical tests capable of measuring resistance are important tools for rehabilitation. One alternative that has recently increased in popularity is the use of elastic tubes, which stand out for being easy to handle, low cost, practical, and feasible. OBJECTIVE: Analyze the test-retest reliability of the knee extensors muscle fatigue resistance test (FRT) with elastic tubes. METHODS: A total of 116 healthy young males, aged between 18 and 30 years old, participated in the study. Participants performed three pre-test stages: orientation, load presentation, and familiarization with equipment, lasting two weeks. Subsequently, they performed the FRT on two occasions (test and retest), with an interval of seven days. The reliability analyzes were performed using the intraclass correlation coefficient (ICC) with 95% confidence interval and typical measurement error (TME), also expressed as coefficient of variation (CV%). RESULTS: The findings regarding the reliability of the test demonstrated satisfactory values (time: ICC = 0.66; 95%CI [0.50; 0.76]; CV(%) = 9.34; repetition: ICC = 0.61; 95%CI [0.46; 0.73], CV(%) = 13.66; rhythm: ICC = 0.52; 95%CI [0.35; 0.67], CV(%) = 10.29. CONCLUSION: From the findings presented, it is concluded that the proposed clinical test with elastic tubes demonstrates evidence of acceptable values.

The effects of cold water immersion with different dosages (duration and temperature variations) on heart rate variability post-exercise recovery: A randomized controlled trial.

OBJECTIVES: The aim of the present study was to investigate the effects of cold water immersion during post-exercise recovery, with different durations and temperatures, on heart rate variability indices. DESIGN: Hundred participants performed a protocol of jumps and a Wingate test, and immediately afterwards were immersed in cold water, according to the characteristics of each group (CG: control; G1: 5' at 9±1°C; G2: 5' at 14±1°C; G3: 15' at 9±1°C; G4: 15' at 14±1°C). METHODS: Analyses were performed at baseline, during the CWI recuperative technique (TRec) and 20, 30, 40, 50 and 60min post-exercise. The average HRV indices of all RR-intervals in each analysis period (MeanRR), standard deviation of normal RR-intervals (SDNN), square root of the mean of the sum of the squares of differences between adjacent RR-intervals (RMSSD), spectral components of very low frequency (VLF), low frequency (LF) and high frequency (HF), scatter of points perpendicular to the line of identity of the Poincaré Plot (SD1) and scatter points along the line of identity (SD2) were assessed. RESULTS: Mean RR, VLF and LF presented an anticipated return to baseline values at all the intervention groups, but the same was observed for SDNN and SD2 only in the immersion for 15min at 14°C group (G4). In addition, G4 presented higher values when compared to CG. CONCLUSIONS: These findings demonstrate that if the purpose of the recovery process is restoration of cardiac autonomic modulation, the technique is recommended, specifically for 15min at 14°C.

Effects of functional training on geometric indices of heart rate variability.

BACKGROUND: Geometric methods provide an analysis of autonomic modulation using the geometric properties of the resulting pattern, and represent an interesting tool in the analysis of heart rate variability (HRV). The aim of this study was to evaluate the impact of functional training on cardiac autonomic modulation in healthy young women using the geometric indices of HRV. METHODS: Data were analyzed from 29 women, and were stratified into a functional training group (FTG, n = 13; 23.00 ± 2.51 years; 21.90 ± 2.82 kg/m2) and a control group (CG, n = 16; 20.56 ± 1.03 years; 22.12 ± 3.86 kg/m2). The FTG received periodized functional training for 12 weeks. The cardiac autonomic modulation of both groups was evaluated before and after this training, and a qualitative analysis was performed using the Poincaré plot. RESULTS: There was a significant increase in the difference of the triangular index (RRTri), SD1, SD2, and RR intervals in the FTG as compared to the CG, and the qualitative analysis from the Poincaré plot showed an increase in the dispersion of beat-to-beat and long-term RR intervals in the functional group after training. No changes were observed in the triangular interpolation of RR interval histogram (TINN) or SD1/SD2. CONCLUSION: Functional training had a beneficial impact on autonomic modulation, as characterized by increased parasympathetic activity and overall variability, thus highlighting the clinical usefulness of this type of training.

Investigation of characteristics and risk factors of sports injuries in young soccer players: a retrospective study.

BACKGROUND: The participation of children and adolescents in sports has become increasingly frequent, including soccer. This growing involvement gives rise to concerns regarding the risk of sports injuries. Therefore, the aim of the present study was to describe the musculoskeletal injuries in young soccer players. METHODS: 301 male soccer players with a mean age 14.67 ± 2.08 years were randomly recruited. The Referred Condition Inquiry was used to collect information on the mechanism of injury and anatomic site affected as well as personal data on the participants. The variables were analyzed based on the degree of association using Goodman's test for contrasts between multinomial populations, with the p < 0.05. RESULTS: Among the 301 athletes, 24.25% reported at least one injury. With regard to height, taller individuals reported more injuries than shorter individuals (62.5% and 37.5%, respectively; p < 0.05). Injuries were more frequent among players with a training duration greater than five years (69.65%) in comparison to those who trained for a shorter duration (30.35%) (p < 0.05). The lower limbs, especially the ankle/foot and knee, were the most affected anatomic sites. Impact was the most common mechanism of injury. CONCLUSION: The young practitioners of soccer analyzed had low rates of injury. The main causal mechanism was the impact. A taller height and longer exposure to training were the main risk factors for injury among young soccer players.

Sports injuries among adolescent basketball players according to position on the court.

BACKGROUND: The participation of children and adolescents in sports, including basketball, is becoming increasingly common, and this increased involvement raises concerns about the potential risk of sports injuries. OBJECTIVE: To analyze the occurrence of sports injuries among young basketball players according to their position on the court and to associate these injuries with risk factors. METHOD: A retrospective, epidemiological study. A sample consisting of 204 basketball players with a mean age of 14.33 ± 1.19 years participated in the study. The players were interviewed using a reported condition questionnaire containing anthropometric and training data as well as information on injuries during the previous 12 months. RESULTS: The frequency of injury was highest among the shooting guards (47.8%), followed by the centers (34.8%) and point guards (17.4%). Among the 204 participants, 40 players reported a total of 46 injuries, representing 0.22 injuries per participant and 1.15 injuries per injured participant. For the shooting guards and centers, statistically significant differences between injured and non-injured players were found related to age, weight, height, length of time in training and number of weekly practice hours (p < 0.05). For point guards, a statistically significant difference between injured and non-injured players was found based on weight alone (p < 0.05). CONCLUSION: The occurrence of injuries among basketball players was low. Injuries were associated with both intrinsic and extrinsic factors among shooting guards and centers, whereas injuries were only associated with weight among point guards.