University of Los Lagos

ABSTRACT This study compared physical fitness adaptations following 8-weeks of flywheel cluster-set and traditional cluster-set training. Seventy-six amateur male field sport athletes (age: 23.5 ± 3.7 years; height: 1.81 ± 0.08 m; body mass: 83.6 ± 14.4 kg) were randomly assigned to flywheel cluster-set, traditional cluster-set, or a control group. Participants underwent pre- and post-intervention assessments for 20 m sprint speed, countermovement jump (CMJ) height, force, and velocity, change of direction (COD) speed, isometric mid-thigh pull (IMTP), and three-repetition maximum (3RM) strength. Both training groups performed quarter-squat and Romanian deadlift exercises twice weekly (four sets of nine repetitions), in cluster blocks of three repetitions (3x3x3) with 45 s intra-set rest. Flywheel blocks included two submaximal ‘momentum repetitions’ followed by three maximal efforts. No significant group × time interactions were found between flywheel and traditional cluster-set groups for any measure. Compared to the control group, both intervention groups significantly improved sprint speed (5 m and 20 m), CMJ height and force, COD ability, and 3RM strength (p = 0.024 to < 0.001; ES = 0.20–1.14). Additionally, the flywheel group improved IMTP strength (p = 0.049, ES = 0.25), whereas the traditional group improved CMJ velocity (p = 0.011, ES = 0.26). In conclusion, both training modalities effectively enhanced physical fitness in field sport athletes, with flywheel training favouring isometric-strength and traditional methods favouring jump-velocity adaptations.

Microalgae grow rapidly, require minimal space, can proliferate in non-agricultural land, do not compete with human food sources, and can be cultivated in a variety of environments, including wastewater. They are considered an ecological source of bioactive compounds, offering an environmentally friendly alternative to conventional industrial production methods, which are often resource-intensive. It is important to emphasize that both the species of microalgae and the specific culture conditions play a decisive role in the generation and storage of valuable bioactive compounds, which can act as biostimulants. Biostimulants are organic compounds or microorganisms capable of enhancing crop quality parameters by optimizing nutrient and water use efficiency, while also strengthening tolerance to abiotic stress. The aim of this article is to provide an updated understanding of biostimulants, their modes of action, and their role in regulating plant responses to abiotic stress. It further incorporates examples of successful trials that demonstrate the advantageous applications of microalgae-based biostimulants, while also addressing the barriers and limitations to their commercialization and integration into sustainable agricultural practices.

IntroductionParalympic athletes with skeletal dysplasia (SD) require specialized strength and conditioning approaches due to unique anthropometric characteristics. This study examines how a constraints-led model optimizes training in an elite shot-putter with short stature.MethodsA case study of a F41 shot-put Paralympic medalist (height: 147 cm; body-mass: 72 kg) through biomechanical analysis and training programming. The intervention combined: modified resistance training addressing joint instability, sport-specific plyometrics adapted for shorter limbs, and environmental adaptations for equipment accessibility. Performance metrics included throwing distance, strength-to-mass ratio, and kinematic measurements of shot-put release.ResultsImplementation yielded a 13.88 m competition throw (Tokyo 2021 Paralympics), with maintained body fat of 12%–14%. Results were achieved without training-related injuries, highlighting the model's efficacy in balancing performance enhancement with joint preservation.ConclusionsA constraints-based approach to strength and conditioning, combined with dynamic periodization and a comprehensive support system, provides an adjustable framework for optimizing performance in Paralympic athletes with SD. This multifaceted approach ensures that both physical and psychological demands are met, enabling sustainable athletic development while accounting for the unique biomechanical and physiological characteristics of athletes with SD. Future research should focus upon refining the application of these principles in diverse adaptive sports to further enhance performance outcomes and reduce injury risks.

In southern Chile, harmful algal blooms (HABs) pose a threat to public health, artisanal fisheries, and the aquaculture industry (mussels and salmon). However, little is known about the environmental factors contributing to outbreaks of HABs in fjord systems. In summer 2017, an oceanographic cruise was carried out to study the physical processes associated with a bloom of the dinoflagellate Karenia spp. in the Gulf of Penas and Taitao Peninsula, Chilean Patagonia, causing a massive mortality of salmon (approximately 170,000 fish, worth USD 390,000). Satellite images from Sentinel-3 were utilized to distinguish between areas with high and low densities of Karenia cells. Cell densities were highest in the waters of the northern Taitao Peninsula (70 × 103 cells L−1), and lowest at the Gulf of Penas. Support vector classification (SVC) based on bands 1 (400 nm), 2 (412.5 nm), and 6 (560 nm) from the Sentinel-3 images and the normalized fluorescence line height (FLH) classified bloom presence/absence with an 83% coincidence rate. The SVC model correctly identified non-bloom areas, with limited false positives, and successfully captured bloom zones where Karenia densities were highest. These results demonstrate the importance of incorporating satellite tools in the design and implementation of monitoring programs for the early detection of HABs, particularly in remote, difficult-to-access areas.

The World Health Organization (WHO) defined youth overweight and obesity as pandemic due to a large global overweight and obesity prevalence of 14.8% and 8.1% in 2023. However, the impact of overweight and obesity on youth muscle strength, morphology, and oxidative capacity is unclear despite increased research efforts. To systematically review the literature and meta-analyze findings on muscle strength, morphology, and oxidative capacity in youth with overweight and/or obesity (OW) versus those with normal-weight (NW). Following PRISMA guidelines, electronic databases (i.e., PubMed, Web of Science, Scopus, CINAHL, MEDLINE) were searched for cross-sectional studies that compared OW with NW regarding the outcomes muscle strength (e.g., absolute, relative [e.g., to fat-free mass, body mass]), morphology (e.g., muscle cross-sectional area [CSA]), and oxidative capacity (e.g., phase II of volume of oxygen [VO2] kinetics). The risk of bias (RoB) was assessed using the Joanna Briggs Institute 8-item checklist. A random-effects three-level meta-analysis was used, and within- as well as between-group effect sizes (Hedges' g [g]) were computed. Study heterogeneity was assessed using I2 statistics. The Grading Recommendation Assessment Development and Evaluation (GRADE) approach was used to evaluate the certainty of evidence. Overall, 15 studies were meta-analyzed, including 1,475 participants aged 8.4 to 16.6years. The mean RoB amounted to 6.1 on a 0 to 8 scale. Muscle absolute strength (n = 346; g = 0.68; p = 0.011; I2 = 59.3% [p < 0.001]) and CSA (n = 1,024; g = 1.12; p < 0.001; I2 = 73% [p < 0.001]) was significantly greater in OW versus NW. However, relative muscle strength tended to be larger in NW versus OW (n = 320; g = -0.455; p = 0.165; I2 = 92.7% [p < 0.001]). Moreover, muscle oxidative capacity was significantly greater in NW versus OW (n = 105; g = -0.58; p = 0.019; I2 = 37.5% [p = 0.18]). GRADE revealed very low (absolute and relative strength and muscle oxidative capacity) to moderate (muscle CSA) certainty of evidence. Absolute muscle strength and CSA seem larger in OW versus NW, potentially related to the chronic overload during every day and sports-related tasks imposed by overweight and/or obesity. However, relative muscle strength tended to be lower in OW versus NW, suggesting impaired muscle quality in OW. Further, muscle oxidative capacity seems lower in OW versus NW, which might be indicative of muscle mitochondrial dysfunction and impaired oxygen supply, with a potential negative impact on exercise tolerance. However, the cross-sectional nature of included studies, results heterogeneity, and reduced control of confounders among the included studies (e.g., biological maturation) preclude a robust conclusion, due to a low certainty of evidence.

Background. In taekwondo (TKD), high-intensity actions—particularly kicks and rapid changes of direction—are key determinants of sport-specific performance. Kinetic vari-ables derived from unloaded countermovement jumps (CMJs) are employed as proxies of neuromuscular efficiency. However, most studies have examined the link between CMJ outputs and TKD using jump height alone in sport-specific tasks. Objective. To determine the associations between unloaded CMJ-derived kinetic variables and sport-specific performance, identifying key determinants of repeated high-intensity kicking capacity and change-of-direction ability. Methods. Fifteen national-team athletes (nine men, six women; 18–27 years) completed unloaded CMJ testing (Day 1) and, after 48 h, the Taekwondo-Specific Agility Test (TSAT) and the Multiple Frequency Speed of Kick Test (FSKTMULT) (Day 2). Results. For FSKTMULT, jump height (r = 0.545–0.746), take-off velocity (r = 0.548–0.799), and mean power (r = 0.602–0.799) were positively correlated with the number of kicks across all sets (p = 0.001–0.044). Stepwise regression identified mean power as the sole significant predictor, explaining 32–46% of the variance across sets. For TSAT, time correlated negatively with mean power (r = −0.678, p = 0.008), mean force (r = −0.536, p = 0.048), and RFD (0–30%) (r = −0.655, p = 0.011). Mean power and mid-propulsion impulse (30–60%) jointly explained 72.8% of the variance in TSAT time (R2 = 0.728, p &lt; 0.001). Conclusions. Unloaded CMJ mean power and mid-propulsion impulse (30–60%) emerge as proxies of neuromuscular efficiency linked to sport-specific perfor-mance, supporting their use for athlete monitoring and targeted training.

Landscape alterations have strong impacts on the distribution of genetic variation within and between populations, and understanding these effects can provide insights for design conservation strategies. We analyzed 20 georeferenced individuals of pudu deer (Pudu puda) of three populations from southern Chile to obtain genetic diversity and distance parameters based on five polymorphic microsatellite loci. The genetic population structure was assessed by using STRUCTURE 2.3.4 and the effective population sizes (Ne) with NeEstimator 2.0 software. Habitat fragmentation metrics were also analyzed to correlate these data with the genetic variation focused to assess the effect of native forest fragmentation on the genetic structure of pudu deer. The mean number of alleles ranges from 2.8 to 4.2, while the mean number of private alleles ranged from 0.4 to 1.2. The mean observed heterozygosity ranged from 0.423 to 0.547. All populations displayed significant deficits of heterozygotes (FIS = 0.091-0.189, P &amp;lt; 0.0001). The FST on the whole populations and loci was low (mean FST = 0.0942) and without statistical significance (P &amp;gt; 0.05), indicating no genetic differentiation among populations. The STRUCTURE analysis did not reveal a population structure, and the NeEstimator found a markedly low Ne in a population compared to other analyzed populations. Multiple regression analysis indicates that two fragmentation metrics, namely, the proportion of the landscape covered by forest (PLAND) and the patch density (PD), negatively and significantly affected the number of alleles per locus as well as the observed heterozygosity (PLAND, β = -0.8740, P &amp;lt; 0.05; PD, β = -0.6594, P &amp;lt; 0.05). This result suggests that a greater degree of habitat fragmentation contributes to a decrease in genetic variation of pudu deer. Therefore, maintaining the native forest continuity across the distribution range of pudu deer could contribute to preserving the genetic diversity, enhancing the long-term survival of this mammal.

Olympic combat sports (OCS) present complex physical characteristics where cardiorespiratory fitness, flexibility, postural balance, endurance, agility, speed, strength, and muscular power are determinants of physical fitness. This systematic review and meta-analysis aimed to evaluate the effects of OCS interventions on selected physical fitness outcomes among school-aged and university students, compared with active or standard. A systematic literature search was conducted in May 2024 and April 2025 using seven generic databases-PubMed, ProQuest, EBSCOhost, CINAHL Complete, Scopus, Web of Science (core collection), and PEDro (Physiotherapy Evidence Database). The methodological quality and certainty of evidence were assessed using the PRISMA, TESTEX, RoB 2, and GRADE tools. The Hedge; sg effect sizes were computed. Potential sources of heterogeneity, such as subgroup analyses (type of control group, dosage training and age range), were chosen using a fixed-effects or random-effects model, with a minimum of three studies for the corresponding meta-analyses. The protocol was registered in PROSPERO (code: CRD42023391433). Of 1,539 records, 9 RCTs and 4 NRCTs with 1,314 participants were included. Six overall and three subgroup meta-analyses showed significant increases in standing long jump (ES = 1.04; p < 0.001) and sit-and-reach (ES = 0.80; p < 0.05), with no significant differences (p > 0.05) in maximal isometric handgrip strength (MIHS; ES = 0.60), Sargent jump (ES = 0.18), VO2max (ES = 0.39) and 20-m shuttle run test (ES = 0.27). While in the subgroups by dosage in sit-and-reach there were significant improvements (ES = 0.90 to 1.13; p < 0.001) in <60 min per session and according to age range in university students in favor of OCS. Meanwhile in MIHS according to control group, there were significant increases (ES = 0.21; p < 0.05) in favor of OCS versus physical education. The findings suggest that OCS can be a beneficial addition in standing long jump and sit-and-reach. It does not show improvements in cardiorespiratory fitness, MIHS and Sargent jump. However, with respect to dose and age range <60 min in university students is adequate to improve sit-and-reach. OCS is more effective in improving MIHS compared to physical education. https://www.crd.york.ac.uk/PROSPERO/search.

In the context of regenerative agriculture, essential oils (EOs) are emerging as promising alternatives for managing Botrytis cinerea, a highly destructive phytopathogen responsible for significant agricultural losses. This systematic review analyzed 76 eligible articles highlighting increased research activity since 2020, predominantly addressing in vitro antifungal activity, with emerging interest in nanotechnological formulations and field trials. Thymol- and carvacrol-rich EOs demonstrate the highest efficacy. Preliminary findings on microencapsulation and nanoemulsions indicate advancements in stability, solubility, and controlled release, enhancing the EO effectiveness. However, the development of EO-based biopesticides faces challenges due to volatility, lipophilicity, and production costs. Addressing these limitations through innovative formulations and standardizing extraction processes could pave the way for integrating EOs into sustainable pest management systems in viticulture and horticulture. This review also provides critical insights into the current technological readiness levels of EO-based anti-Botrytis products, emphasizing the need for interdisciplinary research to transition laboratory findings into viable commercial solutions.

Recent research underscores the ecological importance of individual niche variation within populations, challenging traditional niche theory that primarily addresses species coexistence at the population level. This article reviews theories and hypoth