scholarly journals Effects of Cluster Sets and Rest-Redistribution on Mechanical Responses to Back Squats in Trained Men

2017 ◽  
Vol 58 (1) ◽  
pp. 35-43 ◽  
Author(s):  
James J. Tufano ◽  
Jenny A. Conlon ◽  
Sophia Nimphius ◽  
Lee E. Brown ◽  
Alex Petkovic ◽  
...  
Keyword(s):  
Repeated Measures ◽  
Rest Period ◽  
P Values ◽  
Mechanical Responses ◽  
Frequent Sets ◽  
Rest Periods ◽  
Main Effect ◽  
Cluster Sets ◽  
Rest Time ◽  
Force Velocity

Abstract Eight resistance-trained men completed three protocols separated by 48-96 hours. Each protocol included 36 repetitions with the same rest duration, but the frequency and length of rest periods differed. The cluster sets of four (CS4) protocol included 30 s of rest after the 4th, 8th, 16th, 20th, 28th, and 32nd repetition in addition to 120 s of rest after the 12th and 24th repetition. For the other two protocols, the total 420 s rest time of CS4 was redistributed to include nine sets of four repetitions (RR4) with 52.5 s of rest after every four repetitions, or 36 sets of single repetitions (RR1) with 12 s of rest after every repetition. Mean (MF) and peak (PF) force, velocity (MV and PV), and power output (MP and PP) were measured during 36 repetitions and were collapsed into 12 repetitions for analysis. Repeated measures ANOVA 3 (protocol) x 12 (repetition) showed a protocol x repetition interaction for PF, MV, PV, MP, and PP (p-values from <0.001 to 0.012). No interaction or main effect was present for MF. During RR1, MV, PV, MP, and PP were maintained, but decreased throughout every 4-repetition sequence during CS4 and RR4. During CS4 and RR4, PF was less following a rest period compared to subsequent repetitions, whereas PF was maintained during RR1. These data indicate that rest redistribution results in similar average kinetics and kinematics, but if total rest time is redistributed to create shorter but more frequent sets, kinetics and kinematics may remain more constant.

scholarly journals Heavy vs Light Load Single-Joint Exercise Performance with Different Rest Intervals

2017 ◽  
Vol 58 (1) ◽  
pp. 197-206 ◽  
Author(s):  
Gilmar Weber Senna ◽  
Bernardo Minelli Rodrigues ◽  
Daniel Sandy ◽  
Estevão Scudese ◽  
Antonino Bianco ◽  
...  
Keyword(s):  
Exercise Performance ◽  
Significant Interaction ◽  
Rest Period ◽  
Upper Body ◽  
Load Testing ◽  
Light Load ◽  
Rest Periods ◽  
Main Effect ◽  
Repetition Number ◽  
Rest Intervals

Abstract The aim of the study was to compare the effect of three distinct rest period lengths between sets of upper body single-joint exercise with different load zones and volume designed for either endurance or hypertrophy (50% or 80% of 1-RM). Sixteen trained men (20.75 ± 2.54 years; 76.35 ± 5.03 kg; 176.75 ± 3.33 cm, 24.53 ± 1.47 kg/m2) performed a test and retest of 1-RM on non-consecutive days. Forty-eight hours after load testing, the participants were randomly assigned to six sessions consisting of four sets of the triceps pull-down, combining different intensities with distinct rest periods between sets. The shorter 1 minute rest promoted a significant reduction in the total repetition number compared to 3 minute rest for both workloads. There was a difference between 3 and 5 minute conditions for the 50% of 1-RM that did not occur for the 80% of 1-RM condition. Both intensities presented significant interaction values for the rest conditions vs. each set (50% p = 0.0001; 80% p = 0.0001). Additionally, significant values were found for the main effect of the performance of subsequent sets (50% p = 0.003; 80% p = 0.001) and rest conditions (50% p = 0.0001; 80% p = 0.0001). In conclusion, for heavier loads (80%) to fatigue, longer rest of 3 to 5 minutes seems to allow for better recovery between sets and thus, promotes a greater volume. However, when training with lighter loads (50%), the magnitude of the rest seems to directly affect the performance of subsequent sets, and also presents a correlation with total volume achieved for the upper body single-joint exercise scheme.

Variability and Impact of Self-Selected Interset Rest Periods During Experienced Strength Training

2019 ◽  
Vol 126 (3) ◽  
pp. 546-558
Author(s):  
P. Ibbott ◽  
N. Ball ◽  
M. Welvaert ◽  
K. G. Thompson
Keyword(s):  
Strength Training ◽  
Correlation Coefficient ◽  
Intraclass Correlation Coefficient ◽  
Power Output ◽  
Intraclass Correlation ◽  
Rest Period ◽  
Subjective Ratings ◽  
Rest Periods ◽  
Significant Difference ◽  
Rest Time

We investigated the variability of strength trained athletes' self-selected rest periods between sets of heavy squat training. Sixteen strength-trained male athletes (Mage = 23, SD = 3 years) completed two squat training sessions 48 hours apart. Each training session consisted of five sets of 5RM squats, interspersed with self-selected interset rest periods. A Gymaware linear optical encoder collected kinetic data for each squat and temporal data for each interset rest period. The participants' subjective ratings of the experience were taken before (Readiness to Lift [RTL]) and after (Rating of Perceived Effort [RPE]) each set. Mean total rest time and mean power output differed significantly between sessions. For both sessions, interset rest period increased, and power output decreased between Sets 3, 4, and 5 (95% CI range [−101, −17]) compared with Set 1. In both sessions, RPE increased significantly in Set 3 compared with Set 1 (95% CI range = [0.68, 2.19]), while RTL decreased significantly from Set 3 (95% CI range [−2.99, −0.58]) compared to Set 1. Interset rest period and power output demonstrated fair reliability between sessions (mean intraclass correlation coefficient = 0.55), while RPE and RTL demonstrated good and excellent reliability, respectively (mean intraclass correlation coefficient = 0.63 and 0.80). In conclusion, highly trained strength athletes demonstrated a significant difference in their between session power output and total rest time when using self-selected interset rest periods, despite stability in their subjective ratings of fatigue and effort. Interset rest periods can be self-selected reliably to complete strength training in heavy squat protocol; however, power output may decline during the set.

Multimodal Effects of Electromyographic Biofeedback: Looking at Children's Ability to Control Precompetitive Anxiety

1986 ◽  
Vol 8 (4) ◽  
pp. 283-303 ◽  
Author(s):  
Marc R. Blais ◽  
Robert J. Vallerand
Keyword(s):  
Repeated Measures ◽  
Rest Period ◽  
Biofeedback Training ◽  
Adaptation Period ◽  
Practice Session ◽  
Placebo Condition ◽  
Significant Group ◽  
Physiological Variables ◽  
Electromyographic Biofeedback ◽  
Rest Periods

This study assessed the multimodal effects of electromyographic biofeedback on highly trait-anxious subjects, boys who scored in the upper quartile of the Sport Competition Anxiety Test (SCAT). Subjects participated in a bogus sport competitive tournament and participated individually in six laboratory sessions that consisted of a practice session and five matches. Each session comprised an adaptation period and three games separated by three rest periods. Biofeedback or placebo condition was administered during the rest periods. Frontalis EMG, heart rate, and respiratory rate were measured at the end of a rest period and immediately before every game (i.e., stress periods). State anxiety (STAIC; Spielberger, Gorsuch, & Lushene, 1970) was measured before every game, and game performance was also recorded. Results from a MANOVA combining the three physiological variables revealed significant variations between rest and stress periods but no significant group differences. Results from univariate repeated measures ANCOVAs on all dependent variables revealed that the biofeedback group was superior to the placebo group in reducing frontalis EMG both during rest periods and in the general competitive setting. Results support the specificity of single-system biofeedback training and are discussed in light of the discriminative/motor skills model and the trophotropic rebiasing model.

Assessing variability in surgical decision making among attending neurosurgeons at an academic center

2020 ◽  
Vol 132 (6) ◽  
pp. 1970-1976
Author(s):  
Ashwin G. Ramayya ◽  
H. Isaac Chen ◽  
Paul J. Marcotte ◽  
Steven Brem ◽  
Eric L. Zager ◽  
...  
Keyword(s):  
Spine Surgery ◽  
Repeated Measures ◽  
Elective Surgery ◽  
Statistical Tests ◽  
Neurosurgical Procedures ◽  
P Values ◽  
Surgical Interventions ◽  
Radiology Reports ◽  
Operative Notes ◽  
First Time

OBJECTIVEAlthough it is known that intersurgeon variability in offering elective surgery can have major consequences for patient morbidity and healthcare spending, data addressing variability within neurosurgery are scarce. The authors performed a prospective peer review study of randomly selected neurosurgery cases in order to assess the extent of consensus regarding the decision to offer elective surgery among attending neurosurgeons across one large academic institution.METHODSAll consecutive patients who had undergone standard inpatient surgical interventions of 1 of 4 types (craniotomy for tumor [CFT], nonacute redo CFT, first-time spine surgery with/without instrumentation, and nonacute redo spine surgery with/without instrumentation) during the period 2015–2017 were retrospectively enrolled (n = 9156 patient surgeries, n = 80 randomly selected individual cases, n = 20 index cases of each type randomly selected for review). The selected cases were scored by attending neurosurgeons using a need for surgery (NFS) score based on clinical data (patient demographics, preoperative notes, radiology reports, and operative notes; n = 616 independent case reviews). Attending neurosurgeon reviewers were blinded as to performing provider and surgical outcome. Aggregate NFS scores across various categories were measured. The authors employed a repeated-measures mixed ANOVA model with autoregressive variance structure to compute omnibus statistical tests across the various surgery types. Interrater reliability (IRR) was measured using Cohen’s kappa based on binary NFS scores.RESULTSOverall, the authors found that most of the neurosurgical procedures studied were rated as “indicated” by blinded attending neurosurgeons (mean NFS = 88.3, all p values < 0.001) with greater agreement among neurosurgeon raters than expected by chance (IRR = 81.78%, p = 0.016). Redo surgery had lower NFS scores and IRR scores than first-time surgery, both for craniotomy and spine surgery (ANOVA, all p values < 0.01). Spine surgeries with fusion had lower NFS scores than spine surgeries without fusion procedures (p < 0.01).CONCLUSIONSThere was general agreement among neurosurgeons in terms of indication for surgery; however, revision surgery of all types and spine surgery with fusion procedures had the lowest amount of decision consensus. These results should guide efforts aimed at reducing unnecessary variability in surgical practice with the goal of effective allocation of healthcare resources to advance the value paradigm in neurosurgery.

The More, the Merrier? Roles of Device-Student Ratio in Collaborative Inquiries and Its Interactions With External Scripts and Task Complexity

2021 ◽  
pp. 073563312110107
Author(s):  
Cixiao Wang ◽  
Huixiao Le
Keyword(s):  
Conceptual Understanding ◽  
Repeated Measures ◽  
Task Complexity ◽  
Mainland China ◽  
Fifth Grade ◽  
Learning Context ◽  
Simple Task ◽  
Fifth Grade Students ◽  
Main Effect ◽  
The Relationship

In collaborative learning, the intuition “the more device, the merrier” is somehow widely acknowledged, but little research has investigated the relationship between device-student ratio and the learning outcome. This study aims to investigate not only the main effect of different device-student ratio, also to identify the moderators in the learning context including task complexity, external script availability and students’ familiarity to the collaboration settings. A three-round quasi-experiment was conducted in a primary school in mainland China, 130 fifth-grade students from four classes participated. Group worksheet including conceptual understanding and problem-solving tasks were used to collect participants’ inquiry performance. Repeated measures ANOVA was employed in data analysis. Findings indicate that 1:m device-student ratio could be beneficial, and external scripts, and prior collaboration experience could moderate such effect. The different effect of 1:m device-student ratio to 1:1 is only significant in the situation when students are faced with relatively simple task, and the effect size is larger when external script is present. When the task is more complicated, such effect of device-student ratio would only emerge after a period of collaboration. This finding challenged the intuition that one-to-one device-student ratio could be better. Related discussions and recommendations to teaching were made.

scholarly journals Statistical analysis of two arm randomized pre-post designs with one post-treatment measurement

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Fei Wan
Keyword(s):  
Treatment Effect ◽  
Repeated Measures ◽  
Informed Choice ◽  
Clinical Effectiveness ◽  
Change Score ◽  
Post Treatment ◽  
Analysis Of Covariance ◽  
Alternative Methods ◽  
Main Effect ◽  
Comparable Performance

Abstract Background Randomized pre-post designs, with outcomes measured at baseline and after treatment, have been commonly used to compare the clinical effectiveness of two competing treatments. There are vast, but often conflicting, amount of information in current literature about the best analytic methods for pre-post designs. It is challenging for applied researchers to make an informed choice. Methods We discuss six methods commonly used in literature: one way analysis of variance (“ANOVA”), analysis of covariance main effect and interaction models on the post-treatment score (“ANCOVAI” and “ANCOVAII”), ANOVA on the change score between the baseline and post-treatment scores (“ANOVA-Change”), repeated measures (“RM”) and constrained repeated measures (“cRM”) models on the baseline and post-treatment scores as joint outcomes. We review a number of study endpoints in randomized pre-post designs and identify the mean difference in the post-treatment score as the common treatment effect that all six methods target. We delineate the underlying differences and connections between these competing methods in homogeneous and heterogeneous study populations. Results ANCOVA and cRM outperform other alternative methods because their treatment effect estimators have the smallest variances. cRM has comparable performance to ANCOVAI in the homogeneous scenario and to ANCOVAII in the heterogeneous scenario. In spite of that, ANCOVA has several advantages over cRM: i) the baseline score is adjusted as covariate because it is not an outcome by definition; ii) it is very convenient to incorporate other baseline variables and easy to handle complex heteroscedasticity patterns in a linear regression framework. Conclusions ANCOVA is a simple and the most efficient approach for analyzing pre-post randomized designs.

scholarly journals No Self Without Salience: Affective and Self-relevance Ratings of 552 Emotionally Valenced and Neutral Dutch Words

2021 ◽  
Author(s):  
Lora I. Dimitrova ◽  
Eline M. Vissia ◽  
Hanneke Geugies ◽  
Hedwig Hofstetter ◽  
Sima Chalavi ◽  
...  
Keyword(s):  
Repeated Measures ◽  
Emotional Valence ◽  
Age And Gender ◽  
Gender And Age ◽  
Main Effect ◽  
Emotional Salience ◽  
And Gender ◽  
The Relationship

AbstractIt is unknown how self-relevance is dependent on emotional salience. Emotional salience encompasses an individual's degree of attraction or aversion to emotionally-valenced information. The current study investigated the interconnection between self and salience through the evaluation of emotional valence and self-relevance. 56 native Dutch participants completed a questionnaire assessing valence, intensity, and self-relevance of 552 Dutch nouns and verbs. One-way repeated-measures ANCOVA investigated the relationship between valence and self, age and gender. Repeated-measures ANCOVA also tested the relationship between valence and self with intensity ratings and effects of gender and age. Results showed a significant main effect of valence for self-relevant words. Intensity analyses showed a main effect of valence but not of self-relevance. There were no significant effects of gender and age. The most important finding presents that self-relevance is dependent on valence. These findings concerning the relationship between self and salience opens avenues to study an individual's self-definition.

Morphophysiological studies of the shoot apex. I. Recurrent growth flushes and their relationship with structural changes in the growing apex of Callistemon viminalis

1968 ◽  
Vol 46 (10) ◽  
pp. 1287-1295 ◽  
Author(s):  
A. N. Purohit ◽  
K. K. Nanda
Keyword(s):  
Structural Changes ◽  
Rest Period ◽  
Growth Cycle ◽  
Active Period ◽  
Active Growth ◽  
Histological Changes ◽  
Floral Buds ◽  
Rest Periods ◽  
Number Of Leaves ◽  
Callistemon Viminalis

The annual growth cycle of Callistemon viminalis consists of three phases: (1) a reproductive phase that continues till the end of February; (2) a vegetative phase that lasts from the end of February till the end of August; and (3) a long dormant phase which lasts till the end of December. The cycle exhibits four growth flushes with alternating periods of active growth and rest. The duration of the successive rest periods increases, leading eventually to the onset of the long dormant phase.The growing apex exhibits more or less similar histological changes in different growth flushes. An increase in divisional activity of the cells of flanking meristem, accompanied by a decline in the elongation of cells of pith rib meristem, characterizes the rest period. During the active period of growth, the cells of the pith rib meristem elongate but the activity of the flanking meristem decreases. The number of leaves produced in each growth flush, therefore, is dependent upon the duration of the preceding rest period, and their size and nature on the duration of active growth. In growth flush 1 the cells of the rib meristem show elongation twice during the active period corresponding with the separation of floral buds and of foliage leaves respectively. In the long dormant phase, on the other hand, the cells of the flanking meristem show high divisional activity twice, first during September when new leaf primordia are initiated, and again during November when floral buds are initiated. Events of great significance thus occur during the long dormant phase. The reproductive development is characterized by a marked increase in the rate of cell division in the flanking meristem accompanied by cessation of growth, the features that characterize the rest period as well.

Effect of Healing on Fatigue Law Parameters of Asphalt Binders

2012 ◽  
Vol 2293 (1) ◽  
pp. 96-105 ◽  
Author(s):  
Arianna Stimilli ◽  
Cassie Hintz ◽  
Zhijun Li ◽  
Raul Velasquez ◽  
Hussain U. Bahia
Keyword(s):  
Fatigue Life ◽  
Asphalt Binder ◽  
Rest Period ◽  
Power Laws ◽  
Asphalt Binders ◽  
Traffic Loading ◽  
Damage Level ◽  
Rest Periods ◽  
Pavement Structure ◽  
Number Of Cycles

Asphalt binder has the ability to self-heal during rest periods when repetitive loading is applied. Studying the effect of rest on fatigue law parameters provides useful insight into the healing capabilities of asphalt binders. Currently, standard testing and analysis procedures to quantify asphalt binder healing capability are limited and difficult to implement in practice. Fatigue is known to depend on both traffic loading and pavement structure. Power law relations (e.g., Nf = Aγ−B) are commonly used for fatigue analysis of pavement materials. Power laws are used to estimate fatigue life (i.e., number of cycles to failure, Nf) as a function of load amplitude (e.g., strain, γ), which is a reflection of the pavement structure. In this study, testing consisted of strain-controlled time sweeps in the dynamic shear rheometer with a single rest period inserted at a specified damage level. With the selected test, the effect of healing on the relationship between fatigue life and strain was investigated. Nine neat and modified binders were tested. Healing testing was conducted at multiple age levels and strains. Healing that resulted from a single rest period had an insignificant effect on fatigue performance compared with modification and oxidative aging. Although this paper highlights the challenges of using few rest periods to predict healing potential, preliminary results of testing with multiple rest periods show the importance of healing. Further investigation is needed to verify the effect of multiple rest periods on binder fatigue.

scholarly journals Sex Differences, Hormone Fluctuations, Ankle Stability, and Dynamic Postural Control

2012 ◽  
Vol 47 (2) ◽  
pp. 143-148 ◽  
Author(s):  
Hayley Ericksen ◽  
Phillip A. Gribble
Keyword(s):  
Menstrual Cycle ◽  
Postural Control ◽  
Repeated Measures ◽  
Balance Test ◽  
Healthy Women ◽  
Ankle Stability ◽  
Ankle Arthrometer ◽  
Main Effect ◽  
Star Excursion Balance Test ◽  
Anterior Posterior

Context: Hormonal fluctuation as a risk factor in anterior cruciate ligament injury has been investigated with conflicting results. However, the influence of hormone fluctuations on ankle laxity and function has not been thoroughly examined. Objective: To examine the potential hormone contributions to ankle laxity and dynamic postural control during the preovulatory and postovulatory phases of the menstrual cycle using an ankle arthrometer and the Star Excursion Balance Test in healthy women. The cohort group consisted of male control participants. Design: Cohort study. Setting: Research laboratory. Patients or Other Participants: Twenty healthy women (age = 23.8 ± 6.50 years, height = 163.88 ± 8.28 cm, mass = 63.08 ± 12.38 kg) and 20 healthy men (age = 23.90 ± 4.15 years, height = 177.07 ± 7.60 cm, mass = 80.57 ± 12.20 kg). Intervention(s): Ankle stability was assessed with anterior-posterior and inversion-eversion loading. Dynamic postural control was assessed with the posteromedial reaching distance of the Star Excursion Balance Test. Main Outcome Measure(s): Female participants used ovulation kits for 3 months to determine the time of ovulation; during their preovulatory and postovulatory phases, they were tested in the laboratory with an ankle arthrometer and the Star Excursion Balance Test. Male participants were tested on similar dates as controls. For each dependent variable, a time by side by sex repeated-measures analysis of variance was performed. Statistical significance was set a priori at P &lt; .05. Results: For anterior-posterior laxity, a side main effect was noted (F1,38 = 10.93, P = .002). For inversion-eversion laxity, a sex main effect was seen (F1,38 = 10.75, P = .002). For the posteromedial reaching task, a sex main effect was demonstrated (F1,38 = 8.72, P = .005). No influences of time on the dependent variables were evident. Conclusions: Although women presented with more ankle inversion-eversion laxity and less dynamic postural control, hormonal fluctuations during the menstrual cycle (preovulatory compared with postovulatory) did not affect ankle laxity or dynamic postural control, 2 factors that are associated with ankle instability.

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