Time Course of Neuromuscular, Hormonal, and Perceptual Responses Following Moderate- and High-Load Resistance Priming Exercise

2020 ◽  
pp. 1-11
Author(s):  
Peter W. Harrison ◽  
Lachlan P. James ◽  
David G. Jenkins ◽  
Michael R. McGuigan ◽  
Robert W. Schuster ◽  
...  
Keyword(s):  
Time Course ◽  
Load Resistance ◽  
High Load ◽  
Diurnal Changes ◽  
Countermovement Jump ◽  
Squat Jump ◽  
Psychophysiological State ◽  
Moderate Load ◽  
Priming Exercise ◽  
And Control

Purpose: The aim of this study was to map responses over 32 hours following high-load (HL) and moderate-load (ML) half-squat priming. Methods: Fifteen participants completed control, HL (87% 1RM), and ML (65% 1RM) activities in randomized, counterbalanced order. Countermovement jump (CMJ), squat jump (SJ), saliva testosterone, saliva cortisol, and perceptual measures were assessed before and 5 minutes, 8 hours, 24 hours, and 32 hours after each activity. Results are presented as percentage change from baseline and 95% confidence interval (CI). Cliff delta was used to determine threshold for group changes. Results: SJ height increased by 4.5% (CI = 2.2–6.8, Cliff delta = 0.20) 8 hours following HL. CMJ and SJ improved by 6.1% (CI = 2.1–7.8, Cliff delta = 0.27) and 6.5% (CI = 1.2–11.8, Cliff delta = 0.30), respectively, 32 hours after ML. No clear diurnal changes in CMJ or SJ occurred 8 hours following control; however, increases of 3.9% (CI = 2.9–9.2, Cliff delta = 0.26) and 4.5% (CI = 0.9–8.1, Cliff delta = 0.24), respectively, were observed after 32 hours. Although diurnal changes in saliva hormone concentration occurred (Cliff delta = 0.37–0.92), the influence of priming was unclear. Perceived “physical feeling” was greater 8 hours following HL (Cliff delta = 0.36) and 32 hours after ML and control (Cliff delta = 0.17–0.34). Conclusions: HL priming in the morning may result in small improvements in jump output and psychophysiological state in the afternoon. Similar improvements were observed in the afternoon the day after ML priming.

An Intense, But Ecologically Valid, Resistance Exercise Session Does Not Alter Growth Factors Associated With Cognitive Health

2020 ◽  
Vol 28 (4) ◽  
pp. 605-612
Author(s):  
Kieran J. Marston ◽  
Belinda M. Brown ◽  
Stephanie R. Rainey-Smith ◽  
Sabine Bird ◽  
Linda K. Wijaya ◽  
...  
Keyword(s):  
Growth Factor ◽  
Resistance Exercise ◽  
Perceived Exertion ◽  
Load Resistance ◽  
High Load ◽  
Rating Of Perceived Exertion ◽  
Cognitive Health ◽  
Factors Associated ◽  
Moderate Load ◽  
Middle Aged Adults

The purpose of this investigation was to assess the acute changes in growth factors associated with cognitive health following two ecologically valid, intense resistance exercise sessions. Twenty-nine late-middle-aged adults performed one session of either (a) moderate-load resistance exercise or (b) high-load resistance exercise. Venous blood was collected prior to warm-up, immediately following exercise and 30 min following exercise. Serum was analyzed for brain-derived neurotrophic factor, insulin-like growth factor 1, and vascular endothelial growth factor. Session intensity was determined by blood lactate concentration and session rating of perceived exertion. Postexercise blood lactate was greater following moderate-load when compared with high-load resistance exercise. Subjective session intensity was rated higher by the session rating of perceived exertion following moderate-load when compared with high-load resistance exercise. No differences were observed in serum growth factor levels between groups. Ecologically valid and intense moderate-load or high-load exercise methods do not alter serum growth factor levels in late-middle-aged adults.

Hunger is suppressed after resistance exercise with moderate-load compared to high-load resistance exercise: the potential influence of metabolic and autonomic parameters

2020 ◽  
Vol 45 (2) ◽  
pp. 180-186 ◽  
Author(s):  
Marcelo Conrado Freitas ◽  
Valéria Leme Gonçalves Panissa ◽  
Sabrina Alves Lenquiste ◽  
Fernanda de Maria Serra ◽  
Caique Figueiredo ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Resistance Exercise ◽  
Lactate Concentration ◽  
Load Condition ◽  
Load Resistance ◽  
High Load ◽  
Autonomic Modulation ◽  
Rest Interval ◽  
Moderate Load

The purpose of present study was to compare the effects of moderate-load versus high-load resistance exercise (RE) on hunger response, blood lactate, glucose, and autonomic modulation in trained men, and to examine the correlations between these parameters. For this, 11 recreationally resistance-trained males performed 2 randomized trials: moderate-load (6 sets at 70% 1-repetition maximum (1RM) and a 90-s rest interval between sets) and high-load (6 sets at 90% 1RM and a 180-s rest interval between sets) leg-press exercise until movement failure. The subjective rating of hunger was obtained through a visual analog scale. Glucose and lactate concentration were evaluated at rest, immediately after exercise, and 30 min after exercise. Heart rate variability was recorded at baseline and during recovery (until 30 min after exercise) to assess autonomic modulation. The moderate-load condition induced lower subjective hunger ratings than the strength condition immediately after exercise (19.7 ± 16.6 vs 47.3 ± 27.7 mm), 30 min after exercise (33.6 ± 22.9 vs 58.5 ± 29.9 mm), and 60 min after exercise (43.8 ± 26.6 vs 67.8 ± 27.9 mm) (p < 0.05) and lower area under the curve hunger in relation to the high-load condition (p < 0.006). Moderate-load RE presented greater lactate concentration and induced slower heart rate variability recovery in relation to high-load RE (p < 0.05), but no difference was found in glucose, as well as no correlations between any of the variables investigated. In conclusion, moderate-load RE induced lower subjective hunger ratings, slower recovery of the parasympathetic nervous system, and higher lactate concentration in relation to high-load RE, but the metabolic variables were not correlated with hunger suppression.

System Identification and Control of the Activated Sludge Process by Use of a Statistical Model

1989 ◽  
Vol 21 (10-11) ◽  
pp. 1161-1172 ◽  
Author(s):  
M. Hiraoka ◽  
K. Tsumura
Keyword(s):  
Control System ◽  
System Identification ◽  
Statistical Model ◽  
Activated Sludge ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Ar Model ◽  
Diurnal Changes ◽  
Activated Sludge Process ◽  
And Control

The authors have been developing a hierarchical control system for the activated sludge process which consists of an upper level system controlling long-term seasonal variations, a control system of intermediate level aiming at optimization of the process and a control system of lower level controlling diurnal changes or hourly fluctuations. The control system using the multi-variable statistical model is one of the most appropriate control systems based on the modern control theory, for applying the lower level control of the activated sludge process. This paper introduces our efforts for developing the reliable data acquisition system, the control experiments applying the AR-model, one of the statistical models which were conducted at a pilot plant and present studies on the system identification and control at a field sewage treatment plant.

scholarly journals Muscular Strength Spurts in Adolescent Male Basketball Players: The INEX Study

2021 ◽  
Vol 18 (2) ◽  
pp. 776
Author(s):  
Eduardo Guimarães ◽  
José A. R. Maia ◽  
Mark Williams ◽  
Filipa Sousa ◽  
Eduardo Santos ◽  
...  
Keyword(s):  
Muscular Strength ◽  
Handgrip Strength ◽  
Height Velocity ◽  
Adolescent Male ◽  
Strength Development ◽  
Maximal Velocity ◽  
Countermovement Jump ◽  
Basketball Players ◽  
Squat Jump ◽  
Medicine Ball

Although successful performance in basketball requires high levels of muscular strength during adolescence, its development is confounded by the effects of normal growth. We examine the timing, intensity and sequence of muscular strength according to biological age (years from peak height velocity (PHV)) and hypothesize that young basketball players attain their peak muscular strength spurts around PHV. A total of 160 adolescent male basketballers, aged 11–15 years, were followed bi-annually over 3 consecutive years. The years from attainment of PHV and peak weight velocity (PWV) were estimated and five muscular strength measures (sit-ups, handgrip, seated medicine ball throw, squat jump and countermovement jump) were aligned to years from PHV in 3-month intervals. Strength velocities were estimated using a non-smooth mathematical model. The mean ages at-PHV and at-PWV were 13.90 ± 1.40 years and 13.90 ± 1.79 years, respectively. Maximal velocity in sit-ups was attained 6 months prior to attainment of PHV (intensity = 10.69 repetitions·year−1), whereas maximal velocity in squat jump occurred 6 months after-PHV (intensity = 3.93 cm·year−1). Handgrip strength, seated medicine ball throw and countermovement jump maximal velocity peaked at-PHV (intensity = 8.47 kgf·year−1, intensity = 0.75 m·year−1, intensity = 5.59 cm·year−1, respectively). In general, maximal velocity spurts did not differ in their timing, with the velocities reaching a peak concurrent with PHV and PWV or within 6 months of its attainment. Basketball coaches, as well as strength and conditioning trainers, should consider individual differences in strength development and be aware of rapid periods of growth in stature when planning and designing muscular strength training regimes.

scholarly journals A Training Proposal to Improve Multidirectional Running Technique in Male and Female Handball Players: A Pilot Study

2021 ◽  
Vol 18 (4) ◽  
pp. 2056
Author(s):  
Carmen Ferragut ◽  
Román Pedreira ◽  
José Julio Espina ◽  
Helena Vila
Keyword(s):  
Team Sports ◽  
T Test ◽  
Control Group ◽  
Sprint Training ◽  
Countermovement Jump ◽  
Squat Jump ◽  
Male And Female ◽  
Intervention Protocol ◽  
Post Test ◽  
Experimental Group

Multidirectional running has been described as an important factor in team sports performance. The aim of the present study was to determine changes in T-test, 505 time, 10 m sprint, squat jump (SJ), countermovement jump (CMJ), countermovement jump right leg (CMJRL), and countermovement jump left leg (CMJLL) following exposure to 12 sessions over 4 weeks of a multidirectional running sprint training intervention in male and female handball players. A total of 31 handball players (15 male and 16 female) were recruited for this study and then randomly assigned to an experimental group (EG) or control group (CG). Male EG players showed improvements in 505 Preferred Side (PS) (p ≤ 0.05), 505 Non-Preferred Side (NPS) (p ≤ 0.05), and 10 m sprint (p ≤ 0.05), while female EG players presented statistically significant improvements between pre- and post-test for the T-test (p ≤ 0.05), 505 PS (p ≤ 0.05), 505 NPS (p ≤ 0.05), and 10 m sprint (p ≤ 0.05). No statistically significant pre- and post-test differences were observed in CG (all p ≥ 0.05) or between male and female players. We found an improvement in handball players’ agility and speed of movement following the intervention protocol, suggesting the need to introduce this program into our training sessions. It may also be necessary to select and develop more specific tests in order to evaluate multidirectional work in handball players.

scholarly journals Post hoc analysis of ellipsoid zone changes beyond the central subfield in symptomatic vitreomacular adhesion patients from the OASIS trial

2021 ◽  
Vol 6 (1) ◽  
pp. e000648
Author(s):  
Swetha Bindu Velaga ◽  
Muneeswar Gupta Nittala ◽  
Michael S Ip ◽  
Luc Duchateau ◽  
SriniVas R Sadda
Keyword(s):  
Time Course ◽  
Vitreomacular Adhesion ◽  
Ellipsoid Zone ◽  
Post Hoc Analysis ◽  
Link Type ◽  
Phase Iiib ◽  
The Status ◽  
Registration Number ◽  
Post Hoc ◽  
And Control

Background/aimsOASIS is a Phase IIIb trial (NCT01429441) assessing long-term outcomes in subjects with symptomatic vitreomacular adhesion (VMA). The purpose of this study is to report on the frequency, severity, location and time course of ellipsoid zone (EZ) alterations in ocriplasmin-treated and sham control eyes in the OASIS study.Methods220 patients (146 ocriplasmin, 74 sham) subjects with VMA were enrolled in this masked post hoc analysis phase IIIb, randomised, sham-controlled double-masked multicentre clinical trial. A masked post hoc analysis of OCT images was performed at the Doheny Image Reading Center from subjects enrolled in the OASIS trial. The status of the EZ band was assessed in three different macular regions: the central subfield (CS) (≤1 mm diameter), the parafoveal area (PAA) (>1 to ≤3 mm) and the perifoveal area (PEA) (>3 to ≤6 mm). The EZ band was rated as normal/intact, full thickness macular hole (FTMH), abnormal but continuous, discontinuous/disrupted or absent at visits from baseline (pretreatment) to week 1 (day 7), month 1 (day 28), month 3, month 6, month 12 and the final follow-up at month 24. EZ band status was compared in both study and control eyes.ResultsA total of 208 patients (138 ocriplasmin, 70 sham) were included in this analysis. At baseline, FTMH was present in 48.6%, 8.0%, 0% and 52.8%, 2.9%, 0% in the CS, PAA and PEA of the ocriplasmin and sham groups, respectively. The EZ was graded to be abnormal but continuous, discontinuous/disrupted or absent at Baseline in 21.0%, 4.3%, 2.8% in the CS, PAA and PEA, respectively, of the ocriplasmin group; and 12.9%, 10.0%, 4.3% in the CS, PAA and PEA of the sham group. For the ocriplasmin group in the PAA, this frequency increased to 6.6% at week 1, was 9.8% at month 1, but improved to 3.8% at month 3, and remained stable to 1.6% at month 24. These differences, however, were not statistically significant.ConclusionsOcriplasmin treatment for symptomatic VMA was associated with EZ abnormalities in a small percentage of patients that was best assessed in regions (PEA) relatively unaffected by the VM interface disease at baseline. The EZ abnormalities were apparent by week 1, persisted at month 1, and appeared to resolve in the majority of cases by month 3.Trial registration numberNCT01429441

Electromyographic And Mechanomyographic Responses During Three Sets To Failure Of Low- Versus High-load Resistance Training.

2015 ◽  
Vol 47 ◽  
pp. 935
Author(s):  
Nathaniel D.M. Jenkins ◽  
Jessie M. Miller ◽  
Noelle Yeo ◽  
Cory M. Smith ◽  
Ethan C. Hill ◽  
...  
Keyword(s):  
Resistance Training ◽  
Load Resistance ◽  
High Load

Acute consumption of p-synephrine does not enhance performance in sprint athletes

2016 ◽  
Vol 41 (1) ◽  
pp. 63-69 ◽  
Author(s):  
Jorge Gutiérrez-Hellín ◽  
Juan José Salinero ◽  
Javier Abían-Vicen ◽  
Francisco Areces ◽  
Beatriz Lara ◽  
...  
Keyword(s):  
Scientific Information ◽  
Monitoring Program ◽  
Well Being ◽  
Placebo Control Trial ◽  
Placebo Control ◽  
Jump Height ◽  
Countermovement Jump ◽  
Squat Jump ◽  
Jump Test ◽  
The Hours

P-Synephrine is a protoalkaloid widely used as an ergogenic aid in sports. This substance has been included in the World Anti-Doping Agency monitoring program, although scientific information about its effects on performance and athletes’ well-being is scarce. The purpose of this investigation was to determine the effectiveness of p-synephrine to increase performance in sprint athletes. In a randomized and counterbalanced order, 13 experienced sprinters performed 2 acute experimental trials after the ingestion of p-synephrine (3 mg·kg−1) or after the ingestion of a placebo (control trial). Forty-five minutes after the ingestion of the substances, the sprinters performed a squat jump, a countermovement jump, a 15-s repeated jump test, and subsequently performed 60-m and 100-m simulated sprint competitions. Self-reported questionnaires were used to assess side-effect prevalence. In comparison with the control trial, the ingestion of p-synephrine did not change countermovement jump height (37.4 ± 4.2 vs 36.7 ± 3.3 cm, respectively; P = 0.52), squat jump height (34.4 ± 3.6 vs 33.9 ± 3.7 cm; P = 0.34), or average 15-s repeated jumps height (31.8 ± 4.1 vs 32.2 ± 3.6 cm; P = 0.18). P-Synephrine did not modify maximal running speed during the 60-m (9.0 ± 0.5 vs 9.0 ± 0.4 m·s−1, respectively; P = 0.55) and 100-m sprint competitions (8.8 ± 0.5 vs 8.8 ± 0.5 m·s−1, respectively; P = 0.92). The ingestion of p-synephrine did not alter the prevalence of headache, gastrointestinal discomforts, muscle pain, or insomnia during the hours following the tests. Acute consumption of 3 mg·kg−1 of p-synephrine was ineffective to increase performance in competitive sprint athletes. Moreover, p-synephrine did not increase the occurrence of side effects after the competition.

Infused salbutamol accentuates acid-induced lung injury in the rat

1986 ◽  
Vol 71 (2) ◽  
pp. 205-209 ◽  
Author(s):  
Stanley Braude ◽  
David Royston
Keyword(s):  
Lung Injury ◽  
Intravenous Infusion ◽  
Time Course ◽  
Weight Ratio ◽  
Dry Weight ◽  
Adrenergic Agonist ◽  
Lung Water ◽  
Significant Difference ◽  
And Control ◽  
Control Infusion

1. The effect in the rat of salbutamol infusion (1 μg min−1 kg−1) on acid-induced lung injury has been determined. Severity of lung injury was assessed by two techniques: the pulmonary clearance of 99mTc-diethylenetriaminepenta-acetate (99mTc-DTPA) and the lung wet/dry weight ratio, giving indices of alveolar epithelial permeability and transendothelial water filtration respectively. 2. Mean half-time of clearance of 99mTc-DTPA was increased significantly in rats who had intratracheal acid-induced injury and control (saline) intravenous infusion (19.4 ± 2.6 min) compared with non-acid-treated rats (98.1 ± 7.2) (P < 0.0001). However, those animals who had intratracheal acid injury and subsequent salbutamol intravenous infusion had significantly faster clearance (11.5 ± 1.9) than the acid and control infusion group (P < 0.05). 3. Gravimetric lung water in the acid-only rats (expressed as wet/dry weight ratio) was increased significantly (6.4 ± 0.3) compared with the non-acid-treated controls (5.4 ± 0.2) (P < 0.01). Acid-treated rats who had salbutamol infused had dramatically increased lung water (10.0 ± 0.6) (P < 0.001 vs acid and control infusion). 4. Intravenous salbutamol infusion itself produced no significant difference in the results for both techniques, compared with the non-acid-treated time-course controls. 5. Infused salbutamol accentuates acid-induced lung injury in the rat. Possible factors responsible for these findings include β2-adrenergic agonist mediated inhibition of hypoxic pulmonary vasoconstriction (HPV) and a predominant β1-adrenergic agonist inotropic effect of salbutamol with resultant rise in pulmonary artery pressure.

Selected Contribution: Acute cellular and molecular responses to resistance exercise

2002 ◽  
Vol 93 (1) ◽  
pp. 394-403 ◽  
Author(s):  
Fadia Haddad ◽  
Gregory R. Adams
Keyword(s):  
Resistance Exercise ◽  
Intracellular Signaling ◽  
Time Course ◽  
Compensatory Hypertrophy ◽  
Molecular Responses ◽  
Single Bout ◽  
And Control ◽  
Myogenic Markers ◽  
Rest Intervals

Training protocols apply sequential bouts of resistance exercise (RE) to induce the cellular and molecular responses necessary to produce compensatory hypertrophy. This study was designed to 1) define the time course of selected cellular and molecular responses to a single bout of RE and 2) examine the effects of interbout rest intervals on the summation of these responses. Rat muscles were exposed to RE via stimulation of the sciatic nerve in vivo. Stimulated and control muscles were obtained at various time points post-RE and analyzed via Western blot and RT-PCR. A single bout of RE increased intracellular signaling (i.e., phosphorylations) and expression of mRNAs for insulin-like growth factor-I system components and myogenic markers (e.g., cyclin D1, myogenin). A rest interval of 48 h between RE bouts resulted in much greater summation of myogenic responses than 24- or 8-h rest intervals. This experimental approach should be useful for studying the regulatory mechanisms that control the hypertrophy response. These methods could also be used to compare and contrast different exercise parameters (e.g., concentric vs. eccentric, etc.).

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