79 research outputs found

    Fatigue Inducing Resistance Training Produces Differences in Perceived Recovery Status and Session Rate of Perceived Exertion Responses

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    Psychophysiological tools have gained substantial traction as methods of assessing fatigue during exercise. Borg’s rate of perceived exertion (RPE) measures exertion levels of various modes of exercise, including resistance training. The perceived recovery status (PRS) scale is recognized as an effective tool when assessing recovery following fatiguing bouts of exercise. Previous PRS and RPE sprint training research, recognized PRS decline with concurrent sRPE increases. However, the relationship between PRS and sRPE during resistance training is unknown. PURPOSE: The aim of this study is to explore the relationship between PRS and sRPE within resistance training. METHODS: Fourteen resistance trained males (n = 7) and females (n = 7) participated in five resistance training sessions. Session 1 consisted of one-repetition maximum (1RM) testing of bench press (BP) and squat (SQ), and familiarization of PRS and sRPE. Sessions 2-5 involved a standardized dynamic warm up followed by four sets of SQ - three warm up sets (55, 65, 75% 1RM) and one working set of as many repetitions as possible (AMRAP) at 85% 1RM. A 10-minute rest period was allotted, followed by four sets of BP adhering to the 4 set protocol. Following a 5-minute rest period, participants completed 4 sets of 2-repetitions in reserve for three accessory lifts (barbell reverse lunge, overhead press, and bent-over row) performed in circuit training fashion (90s rest between circuits). In order, 72hrs, 48hrs, 24hrs, then 6hrs rest was assigned as between session recovery. Prior to each session PRS was recorded and 30 minutes after completion of each session sRPE was logged. PRS and sRPE were measured using a 2 (fatigue) x 4 (sets) repeated measures ANOVA. RESULTS: A significant main effect was revealed within PRS and sRPE (F(2.319, 60.287) = 8.050, p \u3c .001), as well as between PRS and sRPE across sessions (F(2.319, 60.287) = 14.803, p \u3c .001). Bonferroni post hoc adjustment revealed differences in sessions 1 and 2 (2.214(95% CI, 1.091 to 3.338), p \u3c .001), 1 and 3 (2.00 (95% CI, .328 to 3.672), p \u3c .013), 1 and 4 (3.571 (95% CI, 2.425 to 4.718), p \u3c .001), 2 & 4 (1.357 (95% CI, .273 to 2.441), p = .008), as well as 3 and 4 (1.571 (95% CI, .390 to 2.753), p = .005) PRS scores. Furthermore, a significant difference was recognized between PRS and sRPE of sessions 4 (-3.143 (95% CI, -4.456 to 2.192), p \u3c .001). CONCLUSION: These results support and mirror intermittent sprint training PRS and sRPE reports. Moreover, as PRS values decrease, due to fatiguing resistance training sessions, global levels of fatigue (sRPE) increased; thus, further illustrating the PRS scale as a valid metric of assessing pre-exercise recovery

    Macronutrients for High and Low Injury Risk Collegiate Rodeo Athletes Compared to Recommended Dietary Allowances

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    Rodeo is a high-intensity, intermittent sport in nature unlike popular American sports. The production of empirical research outlining the physical demands and ideal training methods connected to rodeo and improving performance has not matched the rate of growth the sport of rodeo has experienced. Particularly regarding nutritional recommendations, limited research explains nutrition and its role in injury prevention and the process of recovery in rodeo athletes. PURPOSE: The purpose was to investigate the differences of macronutrients between high risk and low risk of injury in rodeo athletes compared to recommended daily allowances (RDA). METHODS: College rodeo athletes from a mid-size university in the southwest region were recruited to be a part of the study (n=150). Subjects completed a 3-day food record – 2 non-consecutive standard nutritional intake days and 1 unconventional day. Dietary intake records were input into Elizabeth Stewart Hands and Associates (ESHA) Food Processor Nutrition Analysis Software. Low and high-risk categorization was performed across nine college rodeo events. In accordance with previous literature outlying injury percentages (\u3e10 injuries; low-risk year). Subjects that competed in barrel racing, breakaway, and team roping were categorized as low injury risk athletes. Bull riding, saddle bronc, bareback, team roping, goat-tying, and steer wrestling were grouped as high-risk. The RDA macronutrient percentage recommendations (protein 25%, carbohydrates 55%, fats 20%) were utilized as comparative values. A paired sample t-test (p \u3c .05) was used to analyze the average macronutrients intake of rodeo athletes compared to recommended daily allowance (RDA) for high-risk and low-risk rodeo athletes. RESULTS: High-risk athletes’ average macronutrients were significantly different when compared to the RDA (Kcal pCONCLUSION: These data will be able to expose the surpluses and deficiencies of the dietary intake of the collegiate rodeo athletes. Low-risk rodeo athletes experienced overconsumption in fat and under consume the recommended number of kcals, protein and carbohydrates. High-risk athletes’ data showed under consumption in all areas explored. These data suggest for both adjustments should be made to address these deficiencies

    Slow-stimulated Multifocal ERG in High- and Normal-tension Glaucoma

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    Purpose: To study the ability and sensitivity of the slow stimulation multifocal ERG (mfERG) to detect glaucomatous damage. Methods: Right eyes of 20 patients with normal-tension glaucoma (NTG), 15 patients with high-tension glaucoma (HTG) and 15 healthy volunteers underwent testing with the mfERG (VERIS 4.1TM). The central 50 degrees of the retina were stimulated by 103 hexagons (m-sequence: 213-1, Lmax: 100cd/m2, Lmin: 1cd/m2, background: 50cd/m2). Each m-sequence step was followed by 3 black frames (Lmax: < 1cd/m2). Five response averages of the first order response component (KI) were analyzed: the central 7.5 degrees and the 4 adjoining quadrants. The amplitudes from the first minimum, N1, to the first maximum, P1, and from P1 to the second minimum, N2, were analyzed as well as the latencies of N1, P1, N2 and the latencies of 3 multifocal oscillatory potentials (mfOPs) with their maxima at about 73, 80 and 85ms. Results: For each parameter the percentage of deviation from the mean of the control group was calculated. These values were then added for each individual to form a deviation index (DI). Seventeen patients (85.0%) with NTG and 3 patients (20.0%) with HTG showed a DI outside the normal range. The major changes were observed in the mfOPs of the NTG patients. MfOPs were then selectively filtered at 100-300Hz and their scalar product was analyzed over an epoch of 68-105ms. This confirmed that mfOPs differed significantly from the control in the central 7.5° and, for NTG, in the nasal field. With a logistic regression analysis the mfOPs had a sensitivity to differentiate 85% of the NTG patients and 73% of the HTG patients from normal. Conclusions: Under these conditions, the slow-stimulated mfERG can detect glaucomatous dysfunction in NTG (85.0%). The differences observed between NTG and HTG are in support of a different underlying pathomechanis

    Grip Strength Symmetries in Division I College Baseball Pitchers and Hitters

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    Integrating strength and conditioning coaches and programs for baseball athletes has yielded positive performance outcomes for both hitting and throwing. Among a variety of baseball-specific testing batter, grip strength has shown to significantly correlate with increased swing and throwing velocity. However, no investigations have examined grip strength asymmetries for hitters and pitchers. PURPOSE: The purpose of this study was to examine differences between right and left arm grip strength of baseball pitchers and hitters. METHODS: Division I collegiate baseball players (n = 45, height. (183.52 ± 11.77 cm) weight. (85.96 ± 17.73 kg.) performed dominate and non-dominate maximal grip strength at position specific arm and forearm orientation utilizing the Jamar Hydraulic Hand Dynamometer. Hitters (n = 22) performed grip strength assessments at 90-degree elbow flexion, neutral forearm orientation (NDN). Pitchers (n = 23) performed grip strength assessments at 90-degree elbow flexion, pronated forearm orientation (NDP). Three attempts were permitted to exert maximal force, recorded in kilograms (kg) – highest exerted force was recorded and used for analysis. An independent samples t-test (p \u3c .05) was employed to assess dominate and non-dominate grip strength differences. RESULT: The results indicated no significant differences between pitchers’ dominate NDP (57.39 ± 7.49 kg) and non-dominate NDP (56.0 ± 7.63 kg), t(44) = .624, p = .966. Likewise, hitters presented no significant difference between dominate NDN (60.68 ± 10.15 kg) and non-dominate NDN (55.27 ± 11.31 kg) t(42) = 1.669, p = .264. CONCLUSION: Contrary to common belief, these results suggest baseball players do not present significant grip strength asymmetries. While baseball skills (i.e., throwing, hitting) require adequate grip strength to produce favorable performances outcomes, these single arm/hand movements do not place baseball players in a concerning asymmetrical grip strength state. Utilization of both hands during hitting provides reasonable explanations for the results of hitters. For pitchers, glove movement and skill, along with typical strength and conditioning may contribute to improvements in non-dominate grip strength. Furthermore, these results suggest equivalent bilateral strength may be a necessity of collegiate baseball players

    Sex-Specific Pre-Session PRS Difference between Bouts of Fatiguing Resistance Training

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    The perceived recovery status (PRS) scale, a valid psychophysiological tool, provides a scalar representation of varying levels of an individualized recovery status before or during various modes of exercise. Previous investigations recognize females as more fatigue resilient, quantified via the PRS scale, than males during repeated sprint performance. To the best of our knowledge, no investigations have examined the sex-specific PRS responses during multi-session resistance training. PURPOSE: The purpose of this study was to compare male and female PRS scores for multi-session fatiguing resistance training with incremental decline intersession recovery periods. METHODS: Subjects consisted of 14 trained males (n = 7) and females (n = 7) that participated in five resistance training sessions. Session 1 consisted of one repetition maximum (1RM) testing for barbell back squat (SQ) and barbell bench press (BP); additionally, during session 1, subjects were given standardized instructions explaining how to interpret the PRS scale (familiarization). PRS was collected prior to each training session. Seventy-two hours after session 1, participants completed a standardized dynamic warm up, followed by a comprehensive, fatiguing resistance training session that began with 3 sets of 55%, 65%, and 75% 1RM, followed by 1 set of as many repetitions as possible (AMRAP) at 85% 1RM for SQ. Ten minutes of recovery was provided upon completion of SQ, before completing the same 4 set routine for BP. Upon 5-minute rest, participants completed 4 set of 2 repetitions in reserve (RIR) for barbell reverse lunge, barbell shoulder press, and barbell bent-over row in circuit format with 90 seconds rest between circuits. In order, 72hrs, 48hrs, 24hrs, and 6hrs rest periods were assigned as intersession recovery. A 2 (sex) x 4 (session) mixed factorial ANOVA was used to determine the sex-specific responses to resistance training. RESULTS: No significant main effect was revealed between males and females PRS scores across sets. However, a statistically significant main effect of PRS scores was illustrated across sets [F (2.323, 27.875) =19.363, pCONCLUSION: These results suggest males and females globally recover similarly from fatigue induced resistance training. However, these data also suggest optimal intersession recovery duration may differ between the sexes – males reported significantly less recovered 48hr after training (between set 2 and 3), while female recovery decline after 48hr was an insignificant change; thus, aligning with previous reports of greater fatigue resilience appearing in females versus males

    A Novel Mouse Fgfr2 Mutant, Hobbyhorse (hob), Exhibits Complete XY Gonadal Sex Reversal

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    The secreted molecule fibroblast growth factor 9 (FGF9) plays a critical role in testis determination in the mouse. In embryonic gonadal somatic cells it is required for maintenance of SOX9 expression, a key determinant of Sertoli cell fate. Conditional gene targeting studies have identified FGFR2 as the main gonadal receptor for FGF9 during sex determination. However, such studies can be complicated by inefficient and variable deletion of floxed alleles, depending on the choice of Cre deleter strain. Here, we report a novel, constitutive allele of Fgfr2, hobbyhorse (hob), which was identified in an ENU-based forward genetic screen for novel testis-determining loci. Fgr2hob is caused by a C to T mutation in the invariant exon 7, resulting in a polypeptide with a mis-sense mutation at position 263 (Pro263Ser) in the third extracellular immunoglobulin-like domain of FGFR2. Mutant homozygous embryos show severe limb and lung defects and, when on the sensitised C57BL/6J (B6) genetic background, undergo complete XY gonadal sex reversal associated with failure to maintain expression of Sox9. Genetic crosses employing a null mutant of Fgfr2 suggest that Fgr2hob is a hypomorphic allele, affecting both the FGFR2b and FGFR2c splice isoforms of the receptor. We exploited the consistent phenotype of this constitutive mutant by analysing MAPK signalling at the sex-determining stage of gonad development, but no significant abnormalities in mutant embryos were detected

    TOETVA parathyroid autofluorescence detection: hANDY-i endoscopy attachment

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    BackgroundTreatment options for thyroid pathologies have expanded to include scarless and remote access methods such as the transoral endoscopic thyroidectomy vestibular approach (TOETVA). Currently, no standardized methods exist for locating parathyroid glands (PGs) in patients undergoing TOETVA, which can lead to parathyroid injury and subsequent hypocalcemia. This early feasibility study describes and evaluates the hANDY-i endoscopic attachment for detecting PGs in transoral thyroidectomy.MethodsWe used a prototype parathyroid autofluorescence imager (hANDY-i) that was mounted to a 10-mm 0-degree endoscope. The device delivers a split screen view of Red-green-blue (RGB) and near-infrared autofluorescence (NIRAF) which allows for simultaneous anatomical localization and fluorescence visualization of PGs during endoscopic thyroid dissection.ResultsOne cadaveric case and two patient cases were included in this study. The endoscopic hANDY-i imaging system successfully visualized PGs during all procedures.ConclusionThe ability to leverage parathyroid autofluorescence during TOETVA may lead to improved PG localization and preservation. Further human studies are needed to assess its effect on postoperative hypocalcemia and hypoparathyroidism

    Typing myalgic encephalomyelitis by infection at onset: A DecodeME study [version 4; peer review: 2 approved]

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    Background: People with myalgic encephalomyelitis / chronic fatigue syndrome (ME/CFS) experience core symptoms of post-exertional malaise, unrefreshing sleep, and cognitive impairment. Despite numbering 0.2-0.4% of the population, no laboratory test is available for their diagnosis, no effective therapy exists for their treatment, and no scientific breakthrough regarding pathogenesis has been made. It remains unknown, despite decades of small-scale studies, whether individuals experience different types of ME/CFS separated by onset-type, sex or age. Methods: DecodeME is a large population-based study of ME/CFS that recruited 17,074 participants in the first 3 months following full launch. Detailed questionnaire responses from UK-based participants who all reported being diagnosed with ME/CFS by a health professional provided an unparalleled opportunity to investigate, using logistic regression, whether ME/CFS severity or onset type is significantly associated with sex, age, illness duration, comorbid conditions or symptoms. Results: The well-established sex-bias among ME/CFS patients is evident in the initial DecodeME cohort: 83.5% of participants were females. What was not known previously was that females tend to have more comorbidities than males. Moreover, being female, being older and being over 10 years from ME/CFS onset are significantly associated with greater severity.  Five different ME/CFS onset types were examined in the self-reported data: those with ME/CFS onset (i) after glandular fever (infectious mononucleosis); (ii) after COVID-19 infection; (iii) after other infections; (iv) without an infection at onset; and, (v) where the occurrence of an infection at or preceding onset is not known. Among other findings, ME/CFS onset with unknown infection status was significantly associated with active fibromyalgia. Conclusions: DecodeME participants differ in symptoms, comorbid conditions and/or illness severity when stratified by their sex-at-birth and/or infection around the time of ME/CFS onset

    Regulation of Hemolysin Expression and Virulence of Staphylococcus aureus by a Serine/Threonine Kinase and Phosphatase

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    Exotoxins, including the hemolysins known as the alpha (α) and beta (β) toxins, play an important role in the pathogenesis of Staphylococcus aureus infections. A random transposon library was screened for S. aureus mutants exhibiting altered hemolysin expression compared to wild type. Transposon insertions in 72 genes resulting in increased or decreased hemolysin expression were identified. Mutations inactivating a putative cyclic di-GMP synthetase and a serine/threonine phosphatase (Stp1) were found to reduce hemolysin expression, and mutations in genes encoding a two component regulator PhoR, LysR family transcriptional regulator, purine biosynthetic enzymes and a serine/threonine kinase (Stk1) increased expression. Transcription of the hla gene encoding α toxin was decreased in a Δstp1 mutant strain and increased in a Δstk1 strain. Microarray analysis of a Δstk1 mutant revealed increased transcription of additional exotoxins. A Δstp1 strain is severely attenuated for virulence in mice and elicits less inflammation and IL-6 production than the Δstk1 strain. In vivo phosphopeptide enrichment and mass spectrometric analysis revealed that threonine phosphorylated peptides corresponding to Stk1, DNA binding histone like protein (HU), serine-aspartate rich fibrinogen/bone sialoprotein binding protein (SdrE) and a hypothetical protein (NWMN_1123) were present in the wild type and not in the Δstk1 mutant. Collectively, these studies suggest that Stk1 mediated phosphorylation of HU, SrdE and NWMN_1123 affects S. aureus gene expression and virulence
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