scholarly journals Can Creatine Supplementation Interfere with Muscle Strength and Fatigue in Brazilian National Level Paralympic Powerlifting?

Nutrients ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2492
Author(s):  
Carlos Rodrigo Soares Freitas Sampaio ◽  
Felipe J. Aidar ◽  
Alexandre R. P. Ferreira ◽  
Jymmys Lopes dos Santos ◽  
Anderson Carlos Marçal ◽  
...  
Keyword(s):  
Muscle Strength ◽  
Isometric Force ◽  
National Level ◽  
Creatine Supplementation ◽  
Peak Torque ◽  
Fatigue Index ◽  
Force Peak ◽  
Maximum Isometric Force ◽  
Force Time ◽  
Blind Manner

The aim of the present study was to analyze the effect of creatine (Cr) supplementation on peak torque (PT) and fatigue rate in Paralympic weightlifting athletes. Eight Paralympic powerlifting athletes participated in the study, with 25.40 ± 3.30 years and 70.30 ± 12.15 kg. The measurements of muscle strength, fatigue index (FI), peak torque (PT), force (kgf), force (N), rate of force development (RFD), and time to maximum isometric force (time) were determined by a Musclelab load cell. The study was performed in a single-blind manner, with subjects conducting the experiments first with placebo supplementation and then, following a 7-day washout period, beginning the same protocol with creatine supplementation for 7 days. This sequence was chosen because of the lengthy washout of creatine. Regarding the comparison between conditions, Cr supplementation did not show effects on the variables of muscle force, peak torque, RFD, and time to maximum isometric force (p > 0.05). However, when comparing the results of the moments with the use of Cr and placebo, a difference was observed for the FI after seven days (U3: 1.12; 95% CI: (0.03, 2.27); p = 0.02); therefore, the FI was higher for placebo. Creatine supplementation has a positive effect on the performance of Paralympic powerlifting athletes, reducing fatigue index, and keeping the force levels as well as PT.

Reliability of Maximum Isometric Force-Time Parameters during a Leg Press Test in Pubertal Basketball Players

2002 ◽  
Vol 14 (2) ◽  
pp. 193-201 ◽  
Author(s):  
Panagiotis Ioakimidis ◽  
Vasilios Gerodimos ◽  
Eleftherios Kellis ◽  
Spiros Kellis
Keyword(s):  
Isometric Force ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Basketball Players ◽  
Leg Press ◽  
Maximal Force ◽  
Maximum Isometric Force ◽  
Time Parameters ◽  
Relative Scale ◽  
Force Time

Fifteen young basketball players (aged 14.4 – 0.5 yrs) underwent two identical testing sessions spaced one week apart, to determine the reliability of maximum isometric force and force-time parameters during a maximal bilateral isometric leg press effort. The maximal isometric force (MIF), the ratio of maximal force to time (TMIF) to attain maximal force (ARMIF), starting strength (F50), and on a relative scale the time taken to increase the force from 10% to 30%, 60%, and 90% of maximal force were calculated. High intraclass correlation coefficients (ICC) were found for MIF (0.96), ARMIF (0.85), and F50 (0.90). On the relative scale, the ICCs for the times to produce 30%, 60%, and 90% of maximum force were 0.94, 0.95, 0.95, respectively. The present results indicate that maximum isometric force and the force-time parameters during a bilateral leg press can be measured reliably in pubertal basketball players.

MAXIMUM ISOMETRIC MUSCLE STRENGTH AS A PREDICTOR OF ONE REPETITION MAXIMUM IN THE SQUAT TEST

sportlogia ◽  
2020 ◽  
Vol 16 (1) ◽  
pp. 161-172
Author(s):  
Borko Petrović ◽  
◽  
Aleksandar Kukrić ◽  
Radenko Dobraš ◽  
Nemanja Zlojutro ◽  
...  
Keyword(s):  
Muscle Strength ◽  
Linear Regression ◽  
Knee Joint ◽  
Isometric Force ◽  
Male Students ◽  
Repetition Maximum ◽  
Leg Muscles ◽  
Squat Exercise ◽  
Maximum Isometric Force ◽  
Isometric Muscle

This study aims to determine whether maximum isometric muscle strength, exerted at a certain angle in the knee joint (80 °, 110 °, and 140 °), may be used as a predictor of 1RM in the squat movement task. A group of twenty-four male students (N = 24) took part in the research in 2 separate sessions and 7 days of rest between each. In the first session, the anthropometric measurements and assessment of muscle strength, that is 1RM, were measured by maximum repetition to failure method on the Smith machine. The maximum isometric force (Fmax) of the leg muscles was measured by the Alternating Consecutive Maximum Contraction Test in laboratory conditions on a Smith machine using a dynamometer probe and the Globus Ergo Tesys System 1000 software system. Analyzing the results based on linear regression, the authors conclude that, with an accuracy of 84.5%, we can estimate 1RM in the squat exercise measuring the maximum isometric force exerted at an angle in the knee joint of 140 °. The results obtained by this research can be used in practice when assessing 1 RM based on the measurement of the maximum isometric force for a given movement task.

scholarly journals Effects of Ibuprofen Use on Lymphocyte Count and Oxidative Stress in Elite Paralympic Powerlifting

Biology ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 986
Author(s):  
Felipe J. Aidar ◽  
Guacira S. Fraga ◽  
Márcio Getirana-Mota ◽  
Anderson Carlos Marçal ◽  
Jymmys L. Santos ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Lymphocyte Count ◽  
Bench Press ◽  
National Level ◽  
Thiobarbituric Acid ◽  
Peak Torque ◽  
Development Rate ◽  
Fatigue Index ◽  
And Oxidative Stress ◽  
Torque Development

Background: Paralympic Powerlifting (PP) training tends to promote fatigue and oxidative stress. Objective: To analyze the effects of ibuprofen use on performance and oxidative stress in post-training PP athletes. Methodology: Ten national level PP athletes (age: 27.13 ± 5.57) were analyzed for oxidative stress in post-training. The study was carried out in three weeks, (1) familiarization and (2 and 3) evaluated the recovery with the use of a placebo (PLA) and ibuprofen (IBU), 800 mg. The Peak Torque (PT), Torque Development Rate (TDR), Fatigue Index (FI), reactive substances to thiobarbituric acid (TBARS) and sulfhydryl groups (SH) were evaluated. The training consisted of five sets of five repetitions (80–90%) 1-Repetition Maximum (1-RM) in the bench press. Results: The IBU showed a higher PT (24 and 48 h, p = 0.04, ɳ2 p = 0.39), a lower FI (24 h, p = 0.01, ɳ2p = 0.74) and an increased lymphocyte count (p < 0.001; ɳ2p = 4.36). There was no change in oxidative stress. Conclusions: The use of IBU provided improvements in strength and did not protect against oxidative stress.

scholarly journals Effects of high-velocity resistance training and creatine supplementation in untrained healthy aging males

2019 ◽  
Vol 44 (11) ◽  
pp. 1246-1253 ◽  
Author(s):  
Patrick Bernat ◽  
Darren G. Candow ◽  
Karolina Gryzb ◽  
Sara Butchart ◽  
Brad J. Schoenfeld ◽  
...  
Keyword(s):  
Resistance Training ◽  
Muscle Strength ◽  
High Velocity ◽  
Healthy Aging ◽  
Creatine Supplementation ◽  
Muscle Thickness ◽  
Peak Torque ◽  
Lower Body ◽  
Leg Press ◽  
Body Strength

The purpose was to investigate the effects of high-velocity resistance training (HVRT) and creatine supplementation in untrained healthy aging males. Participants were randomized to supplement with creatine (0.1 g·kg−1·day−1 of creatine + 0.1 g·kg−1·day−1 of maltodextrin) or placebo (0.2 g·kg−1·day−1 of maltodextrin) during 8 weeks of HVRT. Prior to and following HVRT and supplementation, assessments were made for muscle strength, muscle thickness, peak torque, and physical performance. There was a significant increase over time for all measures of muscle strength (p < 0.001), muscle thickness (p < 0.001), and some measures of peak torque (knee flexion; 1.05 and 3.14 rad/s; p < 0.001) and physical performance (balance board time-to-completion; p = 0.017). There was a group × time interaction for leg press strength (p = 0.044) and total lower-body strength (leg press, knee flexion, knee extension combined; p = 0.039). The creatine group experienced greater gains in leg press and total lower-body strength compared with the placebo group, with no other differences. HVRT increases muscle strength, muscle thickness, and some measures of peak torque and physical performance in untrained healthy aging males. The addition of creatine supplementation to HVRT further augments the gains in leg press and total lower-body strength. Novelty High-velocity resistance training increases muscle mass and performance. Creatine supplementation increases lower-body muscle strength. High-velocity resistance training and creatine supplementation are safe interventions for aging adults.

scholarly journals Evaluation of Strength and Muscle Activation Indicators in Sticking Point Region of National-Level Paralympic Powerlifting Athletes

2021 ◽  
Vol 6 (2) ◽  
pp. 43
Author(s):  
Felipe J. Aidar ◽  
Filipe Manuel Clemente ◽  
Dihogo Gama de Matos ◽  
Anderson Carlos Marçal ◽  
Raphael Fabrício de Souza ◽  
...  
Keyword(s):  
Muscle Activation ◽  
Isometric Force ◽  
National Level ◽  
Rate Of Force Development ◽  
Static Test ◽  
Force Development ◽  
Intermediate Phases ◽  
Maximum Isometric Force ◽  
Dynamic Time ◽  
Sticking Point

Background: The sticking region is considered an intervening factor in the performance of the bench press with high loads. Objective: To evaluate the strength indicators in the sticking point region in Powerlifting Paralympic athletes. Methods: Twelve Brazilian Powerlifting Paralympic athletes performed maximum isometric force (MIF), rate of force development (RFD), time at MIF, velocity, dynamic time in sticking, and surface electromyography in several distances from the bar to the chest. Results: For velocity, there was a difference between the pre-sticking and sticking region (1.98 ± 0.32 and 1.30 ± 0.43, p = 0.039) and dynamic time between the pre-sticking and the sticking region (0.40 ± 0.16 and 0.97 ± 0.37, p = 00.021). In static test for the MIF, differences were found between 5.0 cm and 15.0 cm (CI 95% 784; 1088; p = 0.010) and between 10.0 cm and 5.0 cm (CI 95% 527; 768; p < 0.001). Regarding the RFD, differences were found (CI 95% 938; 1240; p = 0.004) between 5.0 cm and 25.0 cm and between 10.0 cm and 25.0 cm (CI 95% 513; 732; p < 0.001). In relation to time, there were differences between 5.0 cm and 15.0 cm (CI 95% 0.330; 0.515; p < 0.001), 5.0 cm, and 25.0 cm (CI 95% 0.928; 1.345; p = 0.001), 10.0 cm and 15.0 cm (p < 0.05) and 15.0 cm and 25.0 cm (p < 0.05). No significant differences were observed between the muscles in electromyography, although the triceps showed the highest muscle activation values. Conclusions: The maximum isometric force, rate of force development, time, velocity, and dynamic time had lower values, especially in the initial and intermediate phases in the sticking region.

scholarly journals Static and Dynamic Strength Indicators in Paralympic Power-Lifters with and without Spinal Cord Injury

2021 ◽  
Vol 18 (11) ◽  
pp. 5907
Author(s):  
Luan José Lopes Teles ◽  
Felipe J. Aidar ◽  
Dihogo Gama de Matos ◽  
Anderson Carlos Marçal ◽  
Paulo Francisco de Almeida-Neto ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Isometric Force ◽  
Maximum Velocity ◽  
Dynamic Strength ◽  
Dynamic Tests ◽  
Fatigue Index ◽  
Cord Injury ◽  
Maximum Isometric Force ◽  
Impulse Variability

Background: In Paralympic powerlifting (PP), athletes with and without spinal cord injury (SCI) compete in the same category. Athletes with SCI may be at a disadvantage in relation to the production of muscle strength and the execution of motor techniques. Objective: To analyze the indicators force, dynamic and static, at different intensities, on performance in athletes with and without SCI. Methods: The sample was composed of two groups of PP athletes: SCI (30.57 ± 4.20 years) and other deficiencies (OD; 25.67 ± 4.52 years). Athletes performed a test of maximum isometric force (MIF), time to MIF (Time), rate of force development (RFD), impulse, variability and fatigue index (FI), dynamic tests Mean Propulsive Velocity (MPV), Maximum Velocity (Vmax) and Power. Results: There were differences in the SCI in relation to OD, 50% 1RM (p < 0.05), in relation to MPV and Vmax. There were no differences in the static force indicators. Regarding EMG, there were differences between the SCI triceps in relation to the previous deltoid (p = 0.012). Conclusion: We concluded that the static and dynamic strength indicators are similar in Paralympic powerlifting athletes with spinal cord injury and other disabilities.

Knee Extensor Muscle Strength and Vertical Jumping Performance Characteristics in Pre- and Post-Pubertal Boys

2001 ◽  
Vol 13 (1) ◽  
pp. 60-69 ◽  
Author(s):  
Mati Pääsuke ◽  
Jaan Ereline ◽  
Helena Gapeyeva
Keyword(s):  
Muscle Strength ◽  
Isometric Force ◽  
Knee Extensor ◽  
Peak Torque ◽  
Extensor Muscle ◽  
Performance Characteristics ◽  
Jumping Performance ◽  
Vertical Jumping ◽  
Pubertal Boys ◽  
Knee Extensor Muscle Strength

Knee extensor muscle strength and vertical jumping performance characteristics were compared between 14 pre-pubertal (11-year-old) and post-pubertal (16-year-old) boys. Post-pubertal boys had greater (p < .05) absolute values of maximal isometric force (MF) and rate of force development (RFD), absolute and body mass-related values of isokinetic peak torque of the knee extensor muscles at angular velocities of 60, 180, and 240° · s−1, as well as jumping height in squat, counter-movement, and drop jumps, than pre-pubertal boys. This study indicated an inability to use the positive effect of stretch-shortening cycle to vertical jumping performance in pre- and post-pubertal boys.

Effects of creatine supplementation on isometric force-time curve characteristics

2001 ◽  
Vol 33 (11) ◽  
pp. 1876-1881 ◽  
Author(s):  
MICHAEL G. BEMBEN ◽  
TROY D. TUTTLE ◽  
DEBRA A. BEMBEN ◽  
ALLEN W. KNEHANS
Keyword(s):  
Isometric Force ◽  
Creatine Supplementation ◽  
Time Curve ◽  
Force Time

scholarly journals Evaluation of Training with Elastic Bands on Strength and Fatigue Indicators in Paralympic Powerlifting

Sports ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 142
Author(s):  
Felipe J. Aidar ◽  
Filipe Manuel Clemente ◽  
Luiz Fernandes de Lima ◽  
Dihogo Gama de Matos ◽  
Alexandre Reis Pires Ferreira ◽  
...  
Keyword(s):  
Isometric Force ◽  
Training Session ◽  
Peak Torque ◽  
Background Variable ◽  
Strength And Conditioning ◽  
Elastic Bands ◽  
Before And After ◽  
Post Test ◽  
Maximum Isometric Force ◽  
Evaluation Of Training

Background: Variable resistance training has recently become a component of strength and conditioning programs. Objective: This randomized counterbalanced cross-over study aimed to investigate the use of elastic bands (EB) and the traditional method (TRAD) and force indicators in a training session. Methods: 12 Paralympic athletes (age: 28.60 ± 7.60 years) participated in this three-week study. In the first week, the participants were familiarized with EB and TRAD and were tested for maximal repetition (1-RM). The research occurred in weeks 2 and 3, which included the pre-post training, during which the following measures were extracted: maximum isometric force (MIF), the peak torque (PT), rate of force development (RFD), fatigue index (FI), and time to MIF (Time). The athletes performed two tests, EB and TRAD, separated by a one-week interval. Results: Significant differences were found between the pre- and post-test for 1RM (p = 0.018, η2p = 0.412), MIF (p = 0.011, η2p = 0.415), PT (p = 0.012, η2p = 0.413), and RFD (p = 0.0002, η2p = 0.761). With the use of EB, there was a difference in RFD between TRAD before and EB after (p = 0.016, η2p = 0.761). There were significant differences in the before and after for FI between TRAD and EB (p < 0.001) and for Time (p < 0.001), indicating that training with the use of elastic bands promotes overload, characterized by increased fatigue and decreased strength. Conclusions: Training with EB did not decrease 1RM, PT, MIF or RFD, however, there was an increase in fatigue and time to reach MIF when compared to the method with fixed resistance.

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