Search

Lepidium meyenii Walp (LmW) or Maca, including its bioactive components such as macamides, among others, has demonstrated antioxidant effects. However, the effect size (ES) of LmW on oxidative stress has not been qualitatively described and calculated. The primary objective of this systematic review and meta-analysis was to review and qualitatively describe the studies published up to 2023 that supplemented LmW to control cellular oxidative stress; the secondary objective was to calculate the ES of the different interventions. The search was designed following the PRISMA® guidelines for systematic reviews and meta-analyses and performed in the Web of Science, Scopus, SPORTDiscus, PubMed, and MEDLINE until 2023. The selection of studies included randomized controlled trials, with tests and post-tests, both in vitro and in vivo in animals and humans. The methodological quality and risk of bias were evaluated with the CAMARADES tool. The main variables were reduced glutathione, glutathione peroxidase, superoxide dismutase, and malondialdehyde. The analysis was conducted with a pooled standardized mean difference (SMD) through Hedges' g test (95% CI). Eleven studies were included in the systematic review and eight in the meta-analysis. They revealed a small effect for reduced glutathione (SMD = 0.89), a large effect for glutathione peroxidase (SMD = 0.96), a moderate effect for superoxide dismutase (SMD = 0.68), and a moderate effect for malondialdehyde (SMD = −0.53). According to the results, the phytochemical compounds of LmW effectively controlled cellular oxidative stress, mainly macamides. It was also determined that a higher dose of LmW generated a greater antioxidant effect. However, information concerning humans is scarce. [ABSTRACT FROM AUTHOR]

There is evidence that both intra-serial variable resistance (I-sVR), as pre-activation within the post-activation performance enhancement cycle (PAPE), and creatine and caffeine supplementation increase athletic performance in isolation. However, the effect of the three conditioning factors on 30 m repeated sprint ability (RSA) performance in young soccer players is unknown. This study determined the summative and isolation effect of ergogenic aids and pre-activation in half-back squats (HBSs) with I-sVR on performance in an RSA test in young soccer players. Twenty-eight young soccer players were randomly assigned to either EG1 (n = 7, creatine + caffeine + I-sVR), EG2 (n = 7, creatine + placebo2 + I-sVR), EG3 (n = 7, placebo1 + caffeine + I-sVR), or EG4 (n = 7, placebo1 + placebo2 + I-sVR), using a factorial, four-group-matched, double-blind, placebo-controlled design. Creatine supplementation included 0.3 g/kg/day for 14 days, caffeine supplementation included 0.3 mg/kg per day, and pre-activation in HBS with I-sVR (1 × 5 at 30% 1RM [1.0–1.1 m/s] + 1 × 4 at 60% 1RM [0.6–0.7 m/s]). The RSA test and HBS outcomes were evaluated. Three-way ANOVA showed non-significant differences for the RSA test and HBS outcomes (p > 0.05). At the end of this study, it was found that the three ergogenic aids, together, do not generate a summative effect on the physical performance of young soccer players. However, it is important to analyze individual responses to these specific protocols. [ABSTRACT FROM AUTHOR]

BACKGROUND: Isometric maximal voluntary force (IMVF) is essential for individuals' health and physical performance. Therefore, there is a need for valid and reliable devices to assess IMVF. OBJECTIVE: To determine the validity and reliability of the Valkyria Trainer Balance® portable force platform in its isometric mode. METHODS: Fifty-eight physically healthy individuals (30 men and 28 women) participated in the study. A repeated measures design was used to compare the inter-day test-retest reliability of peak force. The validity of the Valkyria Trainer Balance® force platform was determined by comparing the peak force with the ArtOficio® force platform. The analysis consisted of the intraclass correlation coefficient (ICC), standard error of measurement (SEM), and coefficient of variation (CV). A CV ⩽ 10% and ICC ⩾ 0.80 were considered acceptable reliability, while a ⩽ 5% and ICC ⩾ 0.90 were regarded as high reliability. RESULTS: CV the peak force showed high test-retest inter-day reliability (CV = 4.3% and ICC = 0.99). When comparing both force platforms, there was a 1.1% difference between the two devices. CONCLUSIONS: The results of this study demonstrate that the Valkyria Trainer Balance® force platform is valid and reliable for assessing IMVF in physically healthy individuals. [ABSTRACT FROM AUTHOR]

Copyright of Retos: Nuevas Perspectivas de Educación Física, Deporte y Recreación is the property of Federacion Espanola de Asociaciones de Docentes de Educacion Fisica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Functional autonomy (FA) is a critical factor in determining the quality of life of older adults (OA), especially in the case of older women (OW), as they face a decline in FA in their later years of life. FA should be assessed early, using valid, reliable, and low-cost tests. This study evaluated the test-retest reliability of GDLAM and GDLAM autonomy index (GI) in OW. Thirty-nine OW (71.2 ± 6.50 years) participated in the study. A repeated measures design was used to compare the interday test-retest reliability of the five GDLAM tests (seconds) and the GI (points). The five tests represent activities of daily living, such as dressing or wandering around the house, while the GI provides a weighting of the results of the five tests. The analysis consisted of the intraclass correlation coefficient (ICC), standard error of measurement (SEM), and coefficient of variation (CV). A CV ≤ 10% and an ICC ≥ 0.80 were considered acceptable reliability, whereas a CV ≤ 5% and an ICC ≥ 0.90 were considered high reliability. The outcome of the five tests, represented by the GI, showed high interday test-retest reliability (CV = 6.00% and ICC = 0.91). The results of this study demonstrate that the five tests of the GDLAM protocol and the GI have high interday test-retest reliability and good interday reproducibility. From a practical point of view, the GDLAM protocol allows the assessment of FA of community-dwelling OW, providing background for early diagnosis and, with it, the possibility of developing an individualized physical exercise prescription. [ABSTRACT FROM AUTHOR]

Background: the use of beta-alanine (BA) to increase physical performance in the heavy-intensity domain zone (HIDZ) is widely documented. However, the effect of this amino acid on the post-exertion rating of perceived exertion (RPE), heart rate (HR), and blood lactate (BL) is still uncertain. Objectives: a) to determine the effect of acute BA supplementation on post-exertion RPE, HR, and BL in middle-distance athletes; and b) to determine the effect of acute BA supplementation on physical performance on the 6-minute race test (6-MRT). Material and methods: the study included 12 male middle-distance athletes. The design was quasi-experimental, intrasubject, double-blind & crossover. It had two treatments (low-dose BA [30 mg⋅kg-1] and high-dose BA [45 mg⋅kg-1]) and a placebo, 72 hours apart. The effect of BA was evaluated at the end of the 6-MRT and post-exertion. The variables were RPE, HR and BL, and 6-MRT (m) distance. The statistical analysis included a repeated-measures ANOVA (p < 0.05). Results: the analysis evidenced no significant differences at the end of 6-MRT for all variables (p < 0.05). However, both doses of BA generated a lower post-exertion RPE. The high dose of BA caused significant increases in post-exertion BL (p < 0.05). Conclusion: acute supplementation with BA generated a lower post-exertion RPE. This decrease in RPE and the post-exertion BL increase could be related to an increase in physical performance in HIDZ. [ABSTRACT FROM AUTHOR]

Background. The 6-minute rowing ergometer test (6-minRT) is valid and reliable for establishing maximal aerobic power (MAP) in amateur male rowers. However, ventilatory thresholds (VTs) have not yet been established with their mechanical correspondence in this test. Objective. The primary objective was to determine the VTs in the 6-minRT achieved by amateur male rowers, while the secondary objective was to determine the correspondence between ventilatory, mechanical, and heart rate (HR) outcomes of the 6-minRT. Methods. Sixteen amateur male rowers were part of the study. All participants were instructed to perform an incremental test (IT) and a 6-minRT. Determination of the ventilatory parameters for the first ventilatory threshold (VT1), the second ventilatory threshold (VT2), and 6minRTVO2max were performed by correlating the outcomes of VT1, VT2, and VO2max obtained in the IT, with the outcomes of 6-minRT. For these purposes, Pearson's test was used, with the following criteria: trivial, <0.1; small, 0.1≥ 0.3; moderate, 0.3≥0.5; high, 0.5≥0.7; very high, 0.7≥0.9; or practically perfect, >0.9. The significance level was p < 0.05. Results. The IT analysis determined that VT1 and VT2 correspond to 55 and 80% of VO2max, respectively. A high correlation was observed between IT outcomes in VT1, VT2, and VO2max, with the outcomes of 6-minRT (r > 0.6). Conclusion. Based on IT ventilatory parameters and concordance analysis, VT1 and VT2 of 6-minRT are determined at 55 and 80%, respectively, of both ventilatory parameters and their corresponding mechanical outcomes and HR. [ABSTRACT FROM AUTHOR]

To determine the acute effect of low and high-dose BA trials on maximal aerobic speed (MAS) in endurance athletes. We hypothesized that high doses of BA have a greater effect than low doses, both compared to baseline. Twelve male endurance athletes volunteered for the study (age = 21.8 ± 2.37 years, weight = 69.8 ± 4.36 kg, height = 174 ± 5.45 cm, maximal oxygen uptake = 59.6 ± 3.77 mLO2·kg−1·min−1). The experimental design applied was randomized cross-over, double-blind. Treatment included three 6-minute run tests (6-MRT), the first as a baseline, then randomized 6-MRT with low (30 mg·kg−1) and high (45 mg·kg−1) dose BA trials. The 6-MRTs were separated by 72 hours. The main variable of the study was the distance (m) performed in the 6-MRT. Differences between tests were established through ANOVA and Tukey's multiple comparison tests (p < 0.05). The analysis showed significant differences between baseline and both doses (p < 0.001). No significant differences were observed between low and high-dose BA trials (p > 0.05). Both 30 and 45 mg·kg−1 of BA increased physical performance at maximal aerobic speed in endurance athletes. The acute intake formats described in the present investigation may be helpful for endurance athletes training and competing in aerobic-anaerobic transition zones. [ABSTRACT FROM AUTHOR]