Validity and reliability of "My Jump app" to assess vertical jump performance: a meta-analytic review.

This systematic review and meta-analysis aims to investigate the validity and reliability of the My Jump smartphone application in measuring vertical jump height, specifically using flight-time-based measures. To identify potential studies for inclusion, a comprehensive search strategy was employed in PubMed, Web of Science, Scopus, and EBSCO host databases. Validity was assessed in two ways: (1) mean and standard deviations of My Jump measurements were compared to criterion methods to assess the agreement of raw scores; (2) correlation coefficients evaluated the within-group consistency of rankings between My Jump and criterion methods. Reliability was assessed using intraclass correlation coefficients (ICC). Heterogeneity was evaluated via Cochrane's Q statistic, its p-value, I2 value, and tau2 value. Publication bias was explored through funnel plot symmetry and confirmed with extended Egger's test. Following the search, 21 studies met the inclusion criteria. Results showed no significant difference in raw scores between My Jump and criterion methods, indicating high agreement. High correlation was also found for within-group rankings, suggesting consistency. The My Jump application demonstrated nearly perfect reliability scores. The My Jump application appears to be a valid and reliable tool for sports scientists and strength and conditioning practitioners, offering a cost-effective and accessible means for accurately assessing vertical jump performance in various settings. However, it should be noted that these results are specific to flight-time-based measures, and further research is needed to validate these findings against gold-standard take-off velocity methods.

Effect of Origanum dubium, Origanum vulgare subsp. hirtum, and Lavandula angustifolia essential oils on lipid profiles and liver biomarkers in athletes.

This study aims to determine the effects of essential oils of Origanum dubium (DUB), Origanum vulgare subsp. hirtum (HIR), and Lavandula angustifolia (LAV) on lipid profiles and liver biomarkers in athletes. Thirty-four trained athletes were randomly assigned to one of three experimental groups or the control group (CON). The concentrations of serum lipids and liver biomarkers were assessed before and after the 14-day essential oil intervention. Gas chromatography-mass spectrometry analysis showed 68.0 and 82.1% carvacrol in DUB and HIR, respectively, and 34.50% linalyl acetate and 33.68% linalool in LAV essential oils. One-way analysis of covariance (ANCOVA) indicated a significant difference (p = 0.001) among the groups for high-density lipoprotein cholesterol (HDL-C) when the associated preintervention values were used as a covariate. The related pairwise comparisons revealed that DUB (p = 0.001) and HIR (p = 0.024) had greater HDL-C values than CON. From the two-way ANOVA, an interaction between time (before vs. after) and the groups (DUB vs. HIR vs. LAV vs. CON) was found for HDL-C (p = 0.030). Findings indicated a significant increase in DUB (p = 0.0001) and HIR (p = 0.010) for HDL-C, and there was a significant decrease in DUB (p = 0.023) for low-density lipoprotein cholesterol. However, there was no difference in total cholesterol, triglycerides, and all liver biomarkers.

Performance Differences Between Greco-Roman and Freestyle Wrestlers: A Systematic Review and Meta-Analysis.

ABSTRACT: Ulupinar, S, Özbay, S, Gençoglu, C, and Ince, I. Performance differences between Greco-Roman and freestyle wrestlers: a systematic review and meta-analysis. J Strength Cond Res 35(11): 3270-3279, 2021-This systematic review and meta-analysis aims to summarize evidence on performance differences between Greco-Roman (GR) and freestyle (Fr) wrestlers. Eleven studies met the inclusion criteria (91 individual data and a total of 752 wrestlers). The analysis of handgrip strength comprised 9 outcomes from 5 studies with no significant difference between GR and Fr wrestlers. The analysis of isometric (back or leg) strength comprised 15 outcomes from 6 studies with a significant effect favoring GR wrestlers. The analysis of muscle power comprised 15 outcomes from 5 studies with a significant effect favoring GR wrestlers. The analysis of strength endurance comprised 4 outcomes from 3 studies with no significant difference between GR and Fr wrestlers. The analysis of anaerobic capacity and power comprised 6 outcomes from 3 studies with no significant difference between GR and Fr wrestlers. The analysis of speed comprised 19 outcomes from 7 studies with a significant effect favoring GR wrestlers. The analysis of flexibility comprised 20 outcomes from 6 studies with a significant effect favoring Fr wrestlers. This study indicated that GR wrestlers had greater isometric strength, muscle power, and speed performance, but Fr wrestlers had greater flexibility. Given the significant effect sizes favoring GR wrestlers, it is possible that they focused on training strategies to improve physical strength-power performance. However, considering the significant effect size favoring Fr wrestlers, it is possible that they focused on training strategies to improve flexibility because Fr wrestling techniques require a larger range of motion during both attack and defense.

Effects of sprint distance and repetition number on energy system contributions in soccer players.

BACKGROUND/OBJECTIVE: This study aims to compare the effect of sprint distance and repetition number on performance, physiological responses, and energy systems contributions. METHODS: Eighteen male university league soccer players (age: 19.9 ± 1.6 years, height: 177.9 ± 4.7 cm, body mass: 72.4 ± 6.3 kg, percentage body fat: 8.9 ± 1.8, training experience: 7.4 ± 1.6 years) completed two different repeated sprint protocols: 20 × 20 m (20 × 20) and 10 × 40 m (10 × 40) with 15s and 30s rest intervals, respectively. Oxygen uptake (VO2) were measured during the rest, exercise, and recovery phases. Rest and peak blood lactate concentrations were determined. Using VO2 and lactate values, the energy system contributions were calculated using a mono-exponential model and mathematical calculations. Energy systems contributions and total energy expenditure (TEE) were calculated both for the entire protocol (overall) and for the sprints only. RESULTS: Ratings of perceived exertion (RPE), peak and mean heart rate (HR) responses were significantly higher in the 20 × 20 whereas lactate response was higher in the 10 × 40. TEE was similar between the 10 × 40 (586.3 ± 60.8 kJ) and 20 × 20 (595.6 ± 57.5 kJ). For overall estimations, the 10 × 40 and 20 × 20 presented similar results of oxidative (47.5 ± 5.4 vs 45.7 ± 5.1 kJ min-1) and phosphagen (44.7 ± 5.4 vs (42.9 ± 4.8 kJ min-1) systems contributions whereas glycolytic contribution was higher in the 10 × 40 (15.5 ± 2.2 vs 12.8 ± 2.3 kJ min-1). For sprints only estimation, the phosphagen (257.6 ± 31.5 vs 225.2 ± 28.2 kJ min-1), glycolytic (89.4 ± 13.4 vs 67.3 ± 12.5 kJ min-1), and oxidative (76.9 ± 6.9 vs 72.0 ± 7.9 2 kJ min-1) systems contributions were higher in the 10 × 40. CONCLUSIONS: Although HR and RPE responses were higher in the 20 × 20, phosphagen (during sprints) and glycolytic (during both sprints and overall protocol) were higher in the 10 × 40 protocol. Therefore, the 10 × 40 protocol seems more reasonable for developing or evaluating the anaerobic systems.

Prediction of competition performance via selected strength-power tests in junior weightlifters.

BACKGROUND: Previous studies were limited to physical measurements or included very few performance test batteries, which has hindered the determination of the best tests for predicting competition performance in weightlifters. This study aimed to examine the relationships between body composition, Wingate anaerobic power, vertical jump height, isokinetic strength, handgrip strength, trunk strength, and competition performance and to determine the best predictors of competition performance in male junior weightlifters. METHODS: Sixty-seven male junior weightlifters (age 16.6±1.5 years, height 166.6±5.2 cm, body mass 67.0±9.3 kg) voluntarily participated in this study. After a national weightlifting competition, the participants were evaluated for anthropometric measurements, Wingate anaerobic power, isokinetic strength, vertical jump, handgrip strength, and trunk strength tests. The competition performance of the participants was calculated using the Sinclair equation and used as the dependent variable in statistical analysis. RESULTS: The correlations between the variables calculated from the five strength-power tests and the Sinclair score were significant (r=0.448 to 0.951, P≤0.05). The regression model suggested that the best predictors of weightlifting performance were Wingate mean power, the countermovement jump with arm swing, and body fat percentage, which accounted for approximately 88% of the common variance associated with competition performance in male junior weightlifters. CONCLUSIONS: The results of this study showed that the predictors of weightlifting performance were Wingate mean power, countermovement jump with arm swing, and body fat percentage.