scholarly journals Upper body rate of force development and maximal strength discriminates performance levels in sport climbing

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0249353
Author(s):  
Nicolay Stien ◽  
Vegard Albert Vereide ◽  
Atle Hole Saeterbakken ◽  
Espen Hermans ◽  
Matthew Peter Shaw ◽  
...  
Keyword(s):  
Rate Of Force Development ◽  
The Other ◽  
Upper Body ◽  
Relative Time ◽  
Force Development ◽  
Absolute Time ◽  
Time To Peak ◽  
Maximal Force ◽  
Sport Climbing ◽  
Time Periods

The aim of this study was to assess and compare the maximal force and rate of force development (RFD) between intermediate, advanced and elite climbers using several different methods for calculating RFD. Fifty-seven male climbers (17 intermediate, 25 advanced, and 15 elite) performed isometric pull-ups on a climbing-specific hold while the RFD was calculated using several absolute (50, 100, 150, 200, and 250 ms from onset of force) and relative time periods (25, 50, 75, 95, and 100% of time to peak force). The maximal force was higher among elite climbers compared to advanced (ES = 1.78, p < 0.001) and intermediate climbers (ES = 1.77, p < 0.001), while no difference was observed between intermediate and advanced climbers (P = 0.898). The elite group also showed higher RFD than the other two groups at all relative time periods (ES = 1.02–1.58, p < 0.001–0.002), whereas the absolute time periods only revealed differences between the elite vs. the other groups at 50, 100 and 150 ms from the onset of force (ES = 0.72–0.84, p = 0.032–0.040). No differences in RFD were observed between the intermediate and advanced groups at any time period (p = 0.942–1.000). Maximal force and RFD, especially calculated using the longer periods of the force curve, may be used to distinguish elite climbers from advanced and intermediate climbers. The authors suggest using relative rather than absolute time periods when analyzing the RFD of climbers.

scholarly journals Albanian Aorist and Time Reference Points

2020 ◽  
Vol 10 (3) ◽  
pp. 115
Author(s):  
Muhamet Reçica ◽  
Naser Pajaziti
Keyword(s):  
Reference Point ◽  
Reference Points ◽  
The Other ◽  
Temporal Relations ◽  
Time Dimension ◽  
Relative Time ◽  
Absolute Time ◽  
Temporal System ◽  
The Absolute

Topics related to the structure of the temporal system of Albanian language always give opportunities for new discussions to deal with certain aspects related to various forms of this system, and one of them is the aorist, as a tense containing many semantic, temporal, aspectual, stylistic values, etc. The relationships that exist between the verbal tenses in this system within the absolute time-relative time dimension, which relate to the independent or dependent use of temporal forms against one another in different discoursing contexts, make up an interpretation-based approach to interest. Hence, the essential objective of this paper will be specifically the relations of the Albanian aorist to the other verbal forms, always observed with a time reference point, to illuminate the character of these purely temporal relations against each other under all circumstances of the actions that take place and are displayed by verbal forms in different contexts, relying on the corpus of examined materials.

Time-course Of Changes In Maximal Force And Rate Of Force Development After A Plyometric Training Session

2015 ◽  
Vol 47 ◽  
pp. 356
Author(s):  
Gregory C. Bogdanis ◽  
Panagiotis Veligekas ◽  
Panagiotis Roxanas ◽  
Konstantinos Chiotelis ◽  
Stavros Petrou ◽  
...  
Keyword(s):  
Time Course ◽  
Training Session ◽  
Rate Of Force Development ◽  
Plyometric Training ◽  
Force Development ◽  
Maximal Force

scholarly journals INTERPRETATION OF PROPULSIVE FORCE IN TETHERED SWIMMING THROUGH PRINCIPAL COMPONENT ANALYSIS

2018 ◽  
Vol 24 (3) ◽  
pp. 178-181 ◽  
Author(s):  
Rodrigo Maciel Andrade ◽  
Aylton José Figueira Júnior ◽  
Vanessa Metz ◽  
Alberto Carlos Amadio ◽  
Júlio Cerca Serrão
Keyword(s):  
Principal Component Analysis ◽  
Principal Component ◽  
Component Analysis ◽  
Peak Force ◽  
Rate Of Force Development ◽  
Impulse Generation ◽  
Force Development ◽  
Time To Peak ◽  
Force Time ◽  
Minimum Force

ABSTRACT Introduction: Propulsive force in swimming, represented through impulse, is related to performance. However, since the as different biomechanical parameters contribute to impulse generation, coaches have a difficult task when seeking for performance improvement. Objective: Identify the main components involved in impulse generation in the front crawl stroke. Methods: Fourteen swimmers underwent a 10-second all-out fully tethered swimming test. The following parameters were obtained from the force-time curve: minimum force, peak force, mean force, time to peak force, rate of force development and stroke duration. This stage was followed by a principal component analysis. Results: The principal component analysis showed that component 1, predominantly kinetic, was composed of peak force, mean force and rate of force development, and accounted for 49.25% of total impulse variation, while component 2, predominantly temporal, composed of minimum force, stroke duration, and time to peak force, represented 26.43%. Conclusion: Kinetic parameters (peak force, mean force, and rate of force development) are more closely associated with impulse augmentation and, hypothetically, with non-tethered swimming performance. Level of Evidence II; Diagnostic studies - Investigating a diagnostic test.

Collagen and Vitamin C Supplementation Increases Lower Limb Rate of Force Development

2021 ◽  
pp. 1-9
Author(s):  
Dana M. Lis ◽  
Matthew Jordan ◽  
Timothy Lipuma ◽  
Tayler Smith ◽  
Karine Schaal ◽  
...  
Keyword(s):  
Vitamin C ◽  
Training Program ◽  
Lower Limb ◽  
Mixed Model ◽  
Muscle Power ◽  
Force Plate ◽  
Rate Of Force Development ◽  
Mixed Model Analysis ◽  
Force Development ◽  
Maximal Force

Background: Exercise and vitamin C-enriched collagen supplementation increase collagen synthesis, potentially increasing matrix density, stiffness, and force transfer. Purpose: To determine whether vitamin C-enriched collagen (hydrolyzed collagen [HC] + C) supplementation improves rate of force development (RFD) alongside a strength training program. Methods: Using a double-blinded parallel design, over 3 weeks, healthy male athletes (n = 50, 18–25 years) were randomly assigned to the intervention (HC + C; 20 g HC + 50 mg vitamin C) or placebo (20 g maltodextrin). Supplements were ingested daily 60 min prior to training. Athletes completed the same targeted maximal muscle power training program. Maximal isometric squats, countermovement jumps, and squat jumps were performed on a force plate at the same time each testing day (baseline, Tests 1, 2, and 3) to measure RFD and maximal force development. Mixed-model analysis of variance compared performance variables across the study timeline, whereas t tests were used to compare the change between baseline and Test 3. Results: Over 3 weeks, maximal RFD in the HC + C group returned to baseline, whereas the placebo group remained depressed (p = .18). While both groups showed a decrease in RFD through Test 2, only the treatment group recovered RFD to baseline by Test 3 (p = .036). In the HC + C group, change in countermovement jumps eccentric deceleration impulse (p = .008) and eccentric deceleration RFD (p = .04) was improved. A strong trend was observed for lower limb stiffness assessed in the countermovement jumps (p = .08). No difference was observed in maximal force or squat jump parameters. Conclusion: The HC + C supplementation improved RFD in the squat and countermovement jump alongside training.

scholarly journals Sex-Based Differences in the Upper Body Musculature May Influence Rate of Force Development in High School Students

2019 ◽  
Vol 51 (Supplement) ◽  
pp. 817
Author(s):  
Erica R. Goldstein ◽  
Michael J. Redd ◽  
Tristan M. Starling-Smith ◽  
Alison M. Redd ◽  
Jeffrey R. Stout ◽  
...  
Keyword(s):  
High School ◽  
High School Students ◽  
Rate Of Force Development ◽  
Upper Body ◽  
School Students ◽  
Force Development

scholarly journals The influence of temperature on ryanodine sensitivity and the force-frequency relationship in the myocardium of rainbow trout

1992 ◽  
Vol 167 (1) ◽  
pp. 47-60 ◽  
Author(s):  
L. Hove-Madsen
Keyword(s):  
Rainbow Trout ◽  
Mammalian Species ◽  
Rest Period ◽  
Rate Of Force Development ◽  
Force Frequency ◽  
Maximal Rate ◽  
Force Development ◽  
Time To Peak ◽  
Influence Of Temperature On ◽  
Frequency Relationship

The relationship between stimulation frequency and contraction was established for ventricular strips from rainbow trout heart at 5, 15 and 25 degrees C. Compared to mammalian species, changes in temperature had little impact on force development in trout ventricle at physiologically relevant stimulation frequencies. However, the force-frequency relationship was changed from a biphasic response with a minimum around 0.2 Hz at 5 and 15 degrees C to a monophasic decline in force with increasing frequency at 25 degrees C. Ryanodine reversed the negative force-frequency relationship at 25 degrees C. Potentiation of twitch force after a 5 min rest period was increased from 121 +/− 4% at 15 degrees C to 209 +/− 12% at 25 degrees C. A similar augmentation was seen for the maximal rate of force development. Rest potentiation of both force and maximal rate of force development (dF/dT) was abolished by ryanodine at both 15 and 25 degrees C. The ryanodine concentration causing a half-maximal reduction in rest potentiation of force was 51 nmol l-1 at 25 degrees C and 483 nmol l-1 at 15 degrees C. Rest potentiation was maximally reduced by 10 mumol l-1 ryanodine to 50 and 79% of the value in the absence of ryanodine at 25 and 15 degrees C, respectively. At 5 degrees C, rest potentiation was similar to that at 15 degrees C. At 5 degrees C, there was no rest potentiation of dF/dT and ryanodine did not reduce rest potentiation of force. Instead, rest potentiation was correlated with a potentiation of time to peak tension (TPT) at 5 degrees C. Thus, in trout ventricle, force correlates with TPT at 5 degrees C and seems to be regulated by a ryanodine-insensitive mechanism, while at 25 degrees C force is correlated with the maximal rate of force development and the sarcoplasmic reticulum appears to contribute significantly to excitation-contraction coupling.

The differential effect of metabolic alkalosis on maximum force and rate of force development during repeated, high-intensity cycling

2013 ◽  
Vol 115 (11) ◽  
pp. 1634-1640 ◽  
Author(s):  
Jason C. Siegler ◽  
Paul W. M. Marshall ◽  
Sean Raftry ◽  
Cristy Brooks ◽  
Ben Dowswell ◽  
...  
Keyword(s):  
Sodium Bicarbonate ◽  
High Intensity ◽  
Differential Effect ◽  
Force Production ◽  
Rate Of Force Development ◽  
Maximum Force ◽  
Whole Body ◽  
Peak Power Output ◽  
Force Development ◽  
Maximal Force

The purpose of this investigation was to assess the influence of sodium bicarbonate supplementation on maximal force production, rate of force development (RFD), and muscle recruitment during repeated bouts of high-intensity cycling. Ten male and female ( n = 10) subjects completed two fixed-cadence, high-intensity cycling trials. Each trial consisted of a series of 30-s efforts at 120% peak power output (maximum graded test) that were interspersed with 30-s recovery periods until task failure. Prior to each trial, subjects consumed 0.3 g/kg sodium bicarbonate (ALK) or placebo (PLA). Maximal voluntary contractions were performed immediately after each 30-s effort. Maximal force (Fmax) was calculated as the greatest force recorded over a 25-ms period throughout the entire contraction duration while maximal RFD (RFDmax) was calculated as the greatest 10-ms average slope throughout that same contraction. Fmax declined similarly in both the ALK and PLA conditions, with baseline values (ALK: 1,226 ± 393 N; PLA: 1,222 ± 369 N) declining nearly 295 ± 54 N [95% confidence interval (CI) = 84–508 N; P < 0.006]. RFDmax also declined in both trials; however, a differential effect persisted between the ALK and PLA conditions. A main effect of condition was observed across the performance time period, with RFDmax on average higher during ALK (ALK: 8,729 ± 1,169 N/s; PLA: 7,691 ± 1,526 N/s; mean difference between conditions 1,038 ± 451 N/s, 95% CI = 17–2,059 N/s; P < 0.048). These results demonstrate a differential effect of alkalosis on maximum force vs. maximum rate of force development during a whole body fatiguing task.

The effect of rate of force development on maximal force production: acute and training-related aspects

2007 ◽  
Vol 99 (6) ◽  
pp. 605-613 ◽  
Author(s):  
Andreas Holtermann ◽  
Karin Roeleveld ◽  
Beatrix Vereijken ◽  
Gertjan Ettema
Keyword(s):  
Force Production ◽  
Rate Of Force Development ◽  
Force Development ◽  
Maximal Force ◽  
And Training
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