Relationships Between Body Size, Strength, and Power with Throwing Velocity Following a Strength Training Block in High School Water Polo Players

A high school strength and conditioning program should ideally improve fitness and develop motor skills in athletes. This could be a targeted goal if research details relationships between sport-specific motor skills and measures of fitness in high school athletes. PURPOSE: To investigate the correlations and predictive relationships (controlling for age) between height, body mass, strength, and power on throwing velocity in male high school water polo athletes after a 4-week strength training block. METHODS: Eighteen water polo athletes (age: 15.50±0.20 years; height: 177.05±1.60 cm; body mass: 74.28±3.70 kg) from one high school program were recruited. Testing occurred in one day; age, height and body mass were recorded first. Strength was measured using combined grip strength (right and left hands) and isometric lower-body strength via a leg/back dynamometer. Power was measured by a vertical jump and 2-kg seated medicine ball throw (MBT). Athletes also threw a water polo ball with maximum effort to measure throwing velocity. Partial correlations and stepwise regression controlling for sex were used to calculate relationships between throwing velocity with body size, strength, and power (pRESULTS: Combined grip strength (r=0.712), leg/back strength (r=0.656), and MBT (r=0.684) all showed significant positive relationships with throwing velocity. Age and combined grip strength predicted throwing velocity with 61.3% explained variance (R2=0.658, adjusted R2=0.613, pCONCLUSION: Strength and conditioning programs targeting upper- and lower-body strength and upper-body power could improve motor skills such as throwing in water polo high school athletes irrespective of age, which provided an indirect metric for maturation. The 4-week training block included exercises targeting these qualities (e.g., squats, presses, pull-ups, hang cleans), and this likely impacted the relationships between strength, power, and throwing velocity seen in this study. Strength and conditioning coaches working with overhead throwing sports at the high school level could incorporate upper- and lower-body strength and power exercises, including exercises that target grip strength, into to their training blocks to enhance their athletes’ throwing velocity

Lower-Body Strength Relationships with Sprint, Jump, and Sport-Specific Skill Performance in High School Girls Softball Players

International Journal of Exercise Science 17(4): 86-98, 2024. Softball athletes require multiple fitness traits (e.g., strength, speed, power) and sport-specific skills (e.g., hitting, throwing) for success. Lower-body strength could underpin these qualities; this has received little analysis among high school female athletes. This research investigated correlations between absolute and relative lower-body strength with age, linear speed, lower-body power, and throwing and hitting velocity in high school girls softball athletes. Archival data collected from 34 high school girls softball players (age=14.91±1.00 years; height=1.66±0.07 m; body mass=63.21±9.59 kg) from a private strength and conditioning facility was analyzed. The data included: age, height, and body mass; 0-9.14 and 0-18.29 m sprint interval times; standing broad jump (SBJ) distance (lower-body power); batted ball exit (i.e., hitting) and throwing velocity; and absolute and relative three-repetition maximum (3RM) front squat and hexagonal bar deadlift (HBD). Pearson’s correlations (p\u3c0.05) derived relationships between absolute and relative strength with the fitness and sport-specific tests. The results indicated significant relationships between the 3RM HBD with age (r=0.389) and hitting velocity (r=0.418). The 3RM front squat related to the SBJ (r=0.422) and hitting velocity (r=0.457). Relative 3RM HBD correlated with the 0-18.29 m sprint interval (r=–0.349). These results suggested that a strength and conditioning program that improves the lower-body strength of high school girls softball players could contribute to faster sprinting speed, further horizontal jumps, and greater hitting velocity. The results from this study highlights the value of strength enhancement in high school girls softball athletes and provides support for strength and conditioning program provision for these individuals

Operons

Operons (clusters of co-regulated genes with related functions) are common features of bacterial genomes. More recently, functional gene clustering has been reported in eukaryotes, from yeasts to filamentous fungi, plants, and animals. Gene clusters can consist of paralogous genes that have most likely arisen by gene duplication. However, there are now many examples of eukaryotic gene clusters that contain functionally related but non-homologous genes and that represent functional gene organizations with operon-like features (physical clustering and co-regulation). These include gene clusters for use of different carbon and nitrogen sources in yeasts, for production of antibiotics, toxins, and virulence determinants in filamentous fungi, for production of defense compounds in plants, and for innate and adaptive immunity in animals (the major histocompatibility locus). The aim of this article is to review features of functional gene clusters in prokaryotes and eukaryotes and the significance of clustering for effective function

ODNOSI IZMEĐU MIŠIĆNE SNAGE I MOĆI, I BRZINE BACANJA KOD VATERPOLISTA SREDNJOŠKOLACA NAKON BLOKA TRENINGA SNAGE

A high school strength and conditioning program should ideally improve fitness and develop sport-specific motor skills in athletes. This could be a targeted goal if research details relationships between sport-specific motor skills and measures of fitness in high school athletes. The aim of this study was to investigate the relationships between throwing velocity with muscular strength and power in boys high school water polo athletes after a 4-week resistance training block targeting strength. Eighteen athletes from one high school were recruited. Age, height, and body mass were recorded prior to training. Performance testing occurred in one day after the 4-week training block; strength was measured using combined handgrip strength from both hands and isometric lower-body strength via a leg/back dynamometer. Power was measured by a countermovement jump and 2-kg seated medicine ball throw. As a motor skill metric, participants maximally threw a water polo ball to measure throwing velocity. Partial correlations and stepwise regression controlling for age calculated relationships between throwing velocity with handgrip strength, leg/back strength, the countermovement jump, and medicine ball throw (p<0.05). Combined handgrip strength (r=0.712), leg/back strength (r=0.656), and the medicine ball throw (r=0.684) all showed significant positive relationships with throwing velocity. Age and combined handgrip strength predicted throwing velocity with 61.3% explained variance (r2=0.658, p<0.001). The data indicated that throwing velocity significantly related to handgrip and leg/back strength and upper-body power (measured by the medicine ball throw). As the program targeted these qualities, this could have influenced the relationships with the sport-specific motor skill of throwing.Program snage i kondicije namenjen srednjoškolcima bi idealno trebalo da poboljša kondiciju i razvije motoričke veštine specifične za sport kod sportista. Za ovaj problem bi se moglo naći rešenje ukoliko bi istraživanja detaljno opisala odnose između motoričkih veština specifičnih za sport i kondiciju sportista srednoškolaca. Cilj ovog istraživanja bio je da se ispita odnos između brzine bacanja sa mišićnom snagom i silom kod vaterpolista srednjoškolaca nakon 4-nedeljnog treninga otpora koji je ciljao snagu. Regrutovano je osamnaest sportista iz jedne srednje škole. Starost, visina i telesna masa zabeleženi su pre treninga. Testiranje učinka obavljeno je u jednom danu nakon blok treninga u trajanju od 4 nedelje; snaga je merena korišćenjem kombinovanom snagom stiska obe šake i izometrijske snage donjeg dela tela upotrebom dinamometra nogu/leđa. Sila je merena skokom iz počučnja i bacanjem medicinske lopte od 2 kg sedeći. Radi merenja motoričke veštine, učesnici su maksimalno bacali vaterpolo loptu da bi se izmerila brzina bacanja. Delimične korelacije i kontrola stepena regresije za odnose izračunate su prema uzrastu između brzine bacanja sa snagom stiska, snagom nogu/leđa, skoka iz počučnja i bacanja medicinske lopte (p<0,05). Kombinovana snaga stiska (r=0,712), sila nogu/leđa (r=0,656) i bacanje medicinske lopte (r=0,684) pokazali su značajnu pozitivnu vezu sa brzinom bacanja. Starost i kombinovana snaga stiska predviđaju brzinu bacanja sa 61,3% objašnjene varijanse (r2=0,658, p<0,001). Rezultati su pokazali da je brzina bacanja značajno povezana sa snagom stiska i nogu/leđa i snagom gornjeg dela tela (mereno bacanjem medicinske lopte). Pošto je program ciljao ove kvalitete, mogao bi uticati na odnose sa motoričkom veštinom bacanja koja je specifična za sport

A high frequency of overlapping gene expression in compacted eukaryotic genomes

The gene density of eukaryotic nuclear genomes is generally low relative to prokaryotes, but several eukaryotic lineages (many parasites or endosymbionts) have independently evolved highly compacted, gene-dense genomes. The best studied of these are the microsporidia, highly adapted fungal parasites, and the nucleomorphs, relict nuclei of endosymbiotic algae found in cryptomonads and chlorarachniophytes. These systems are now models for the effects of compaction on the form and dynamics of the nuclear genome. Here we report a large-scale investigation of gene expression from compacted eukaryotic genomes. We have conducted EST surveys of the microsporidian Antonospora locustae and nucleomorphs of the cryptomonad Guillardia theta and the chlorarachniophyte Bigelowiella natans. In all three systems we find a high frequency of mRNA molecules that encode sequence from more than one gene. There is no bias for these genes to be on the same strand, so it is unlikely that these mRNAs represent operons. Instead, compaction appears to have reduced the intergenic regions to such an extent that control elements like promoters and terminators have been forced into or beyond adjacent genes, resulting in long untranslated regions that encode other genes. Normally, transcriptional overlap can interfere with expression of a gene, but these genomes cope with high frequencies of overlap and with termination signals within expressed genes. These findings also point to serious practical difficulties in studying expression in compacted genomes, because many techniques, such as arrays or serial analysis of gene expression will be misleading