scholarly journals Impact of Rest-Redistribution on Fatigue During Maximal Eccentric Knee Extensions

2020 ◽  
Vol 74 (1) ◽  
pp. 205-214
Author(s):  
Justin J. Merrigan ◽  
Margaret T. Jones ◽  
Jan Padecky ◽  
Jan Malecek ◽  
Dan Omcirk ◽  
...  

Abstract Redistributing long inter-set rest intervals into shorter but more frequent rest intervals generally maintains concentric performance, possibly due to improved energy store maintenance. However, eccentric actions require less energy than concentric actions, meaning that shorter but more frequent sets may not affect eccentric actions to the same degree as concentric actions. Considering the increased popularity of eccentric exercise, the current study evaluated the effects of redistributing long inter-set rest periods into shorter but more frequent rest periods during eccentric only knee extensions. Eleven resistance-trained men performed 40 isokinetic unilateral knee extensions at 60°·s−1 with 285 s of total rest using traditional sets (TS; 4 sets of 10 with 95 s inter-set rest) and rest-redistribution (RR; 20 sets of 2 with 15 s inter-set rest). Before and during exercise, muscle oxygenation was measured via near-infrared spectroscopy, and rating of perceived exertion (RPE) was recorded after every 10th repetition. There were no differences between protocols for peak torque (RR, 241.58±47.20 N; TS, 231.64±48.87 N; p=0.396) or total work (RR, 215.26±41.47 J; TS, 209.71±36.02 J; p=0.601), but moderate to large effect sizes existed in later repetitions (6,8,10) with greater peak torque during RR (d=0.66-1.19). For the entire session, RR had moderate effects on RPE (RR, 5.73±1.42; TS, 6.09±1.30; p=0.307; d=0.53) and large effects on oxygen saturation (RR, 5857.4±310.0; TS, 6495.8±273.8; p=0.002, d=2.13). Therefore, RR may maintain peak torque or total work during eccentric exercise, improve oxygen utilization at the muscle, and reduce the perceived effort.

2020 ◽  
Vol 45 (4) ◽  
pp. 421-430 ◽  
Author(s):  
James J. Tufano ◽  
Dan Omcirk ◽  
Jan Malecek ◽  
Anna Pisz ◽  
Matej Halaj ◽  
...  

This study investigated redistributing long inter-set rest intervals into shorter but more frequent intervals at 2 different concentric velocities. Resistance-trained men performed 4 randomised isokinetic unilateral knee extension protocols, 2 at 60°·s−1 and 2 at 360°·s−1. At each speed, subjects performed 40 repetitions with 285 s of rest using traditional sets (TS; 4 sets of 10 with 95 s of inter-set rest) and rest-redistribution (RR; 20 sets of 2 with 15 s inter-set rest). Before and at 2, 5, and 10 min after exercise, tensiomyography (TMG) and oxygenation (near-infrared spectroscopy; NIRS) were measured. NIRS was also measured during exercise, and rating of perceived exertion (RPE) was recorded after every 10 repetitions. At both speeds, RR displayed greater peak torque, total work, and power output during latter repetitions, but there were no differences between TS or RR when averaging all 40 repetitions. The RPE was less during RR at both speeds (p < 0.05). RR increased select muscle oxygen saturation and blood flow at both speeds. There were no effects of protocol on TMG, but effect sizes favoured a quicker recovery after RR. RR was likely beneficial in maintaining performance compared with the latter parts of TS sets and limiting perceived and peripheral fatigue. Novelty Although effective at slow velocities, rest-redistribution was likely more effective during high-velocity movements in this study. Rest-redistribution maintained the ability to produce force throughout an entire range of motion. Rest-redistribution reduced RPE during both high-velocity and high-force movements.


2019 ◽  
Vol 14 (7) ◽  
pp. 980-986
Author(s):  
Peter Ibbott ◽  
Nick Ball ◽  
Marijke Welvaert ◽  
Kevin G. Thompson

Purpose: To assess pacing strategies using prescribed and self-selected interset rest periods and their influence on performance in strength-trained athletes. Methods: A total of 16 strength-trained male athletes completed 3 randomized heavy strength-training sessions (5 sets and 5 repetitions) with different interset rest periods. The interset rest periods were 3 min (3MIN), 5 min (5MIN), and self-selected (SS). Mechanical (power, velocity, work, and displacement), surface electromyography (sEMG), and subjective (rating of perceived exertion) and readiness-to-lift data were recorded for each set. Results: SS-condition interset rest periods increased from sets 1 to 4 (from 207.52 to 277.71 s; P = .01). No differences in mechanical performance were shown between the different interset rest-period conditions. Power output (210 W; 8.03%) and velocity (0.03 m·s−1; 6.73%) decreased as sets progressed for all conditions (P < .001) from set 1 to set 5. No differences in sEMG activity between conditions were shown; however, vastus medialis sEMG decreased as the sets progressed for each condition (1.75%; P = .005). All conditions showed increases in rating of perceived exertion as sets progressed (set 1 = 6.1, set 5 = 7.9; P < .001). Participants reported greater readiness to lift in the 5MIN condition (7.81) than in the 3MIN (7.09) and SS (7.20) conditions (P < .001). Conclusions: Self-selecting interset rest periods does not significantly change performance compared with 3MIN and 5MIN conditions. Given the opportunity, athletes will vary their interset rest periods to complete multiple sets of heavy strength training. Self-selection of interset rest periods may be a feasible alternative to prescribed interset rest periods.


2012 ◽  
Vol 37 (6) ◽  
pp. 1110-1117 ◽  
Author(s):  
Jorge M. Zuniga ◽  
Terry J. Housh ◽  
Clayton L. Camic ◽  
Haley C Bergstrom ◽  
Daniel A. Traylor ◽  
...  

The purpose of this study was to examine mean differences and the patterns of responses for oxygen uptake ([Formula: see text]O2), heart rate (HR), and rating of perceived exertion (RPE) for ramp (15 W·min–1) versus step (30 W increments every 2 min) incremental cycle ergometer tests. Fourteen subjects (age and body mass of 23.2 ± 3.1 (mean ± SD ) years and 71.1 ± 10.1 kg, respectively) visited the laboratory on separate occasions. Two-way repeated measures ANOVAs with appropriate follow-up procedures, as well as paired t tests, were used to analyze the data. In addition, polynomial regression analyses were used to determine the patterns of responses for each dependent variable for the ramp and step tests. The ramp protocol resulted in lower mean [Formula: see text]O2 and HR values at the common power outputs than the step protocol with no differences in RPE. The increased amount of work performed during the step (total work = 75.83 kJ) versus ramp (total work = 65.60 kJ) tests at the common power outputs may have contributed to the greater [Formula: see text]O2 and HR values. The polynomial regression analyses showed that most subjects had the same patterns of responses for the ramp and step incremental tests for HR (86%) and RPE (93%) but different patterns for [Formula: see text]O2 (71%). The findings from the present study suggested that the protocol selection for an incremental cycle ergometer test can affect the mean values for [Formula: see text]O2 and HR, as well as the [Formula: see text]O2 – power output relationship.


2015 ◽  
Vol 13 (2) ◽  
pp. 104-110 ◽  
Author(s):  
Marianna de Freitas Maia ◽  
Gabriel Andrade Paz ◽  
Humberto Miranda ◽  
Vicente Lima ◽  
Claudio Melibeu Bentes ◽  
...  

2010 ◽  
Vol 20 (2) ◽  
pp. 104-114 ◽  
Author(s):  
Matthew S. Ganio ◽  
Jennifer F. Klau ◽  
Elaine C. Lee ◽  
Susan W. Yeargin ◽  
Brendon P. McDermott ◽  
...  

The purpose of this study was to compare the effects of a carbohydrate-electrolyte plus caffeine, carnitine, taurine, and B vitamins solution (CE+) and a carbohydrate-electrolyte-only solution (CE) vs. a placebo solution (PLA) on cycling performance and maximal voluntary contraction (MVC). In a randomized, double-blind, crossover, repeated-measures design, 14 male cyclists (M ± SD age 27 ± 6 yr, VO2max 60.4 ± 6.8 ml · kg−1 · min−1) cycled for 120 min submaximally (alternating 61% ± 5% and 75% ± 5% VO2max) and then completed a 15-min performance trial (PT). Participants ingested CE+, CE, or PLA before (6 ml/kg) and every 15 min during exercise (3 ml/kg). MVC was measured as a single-leg isometric extension (70° knee flexion) before (pre) and after (post) exercise. Rating of perceived exertion (RPE) was measured throughout. Total work accumulated (KJ) during PT was greater (p < .05) in CE+ (233 ± 34) than PLA (205 ± 52) but not in CE (225 ± 39) vs. PLA. MVC (N) declined (p < .001) from pre to post in PLA (988 ± 213 to 851 ± 191) and CE (970 ± 172 to 870 ± 163) but not in CE+ (953 ± 171 to 904 ± 208). At Minutes 60, 90, 105, and 120 RPE was lower in CE+ (14 ± 2, 14 ± 2, 12 ± 1, 15 ± 2) than in PLA (14 ± 2, 15 ± 2, 14 ± 2, 16 ± 2; p < .001). CE+ resulted in greater total work than PLA. CE+, but not PLA or CE, attenuated pre-to-post MVC declines. Performance increases during CE+ may have been influenced by lower RPE and greater preservation of leg strength during exercise in part as a result of the hypothesized effects of CE+ on the central nervous system and skeletal muscle.


Author(s):  
Izabela Aparecida dos Santos ◽  
Marina de Paiva Lemos ◽  
Vitória Helena Maciel Coelho ◽  
Alessandro Moura Zagatto ◽  
Moacir Marocolo ◽  
...  

The acute improvement of performance after photobiomodulation therapy (PBMT) has been reported in different types of exercise. However, the effect on high-intensity and intermittent exercises that are relevant for team sports is unknown. Thus, we evaluated the effect of prior acute application of PBMT on high-intensity and intermittent exercise performance, muscle oxygenation, and physiological/perceptual indicators in amateur female futsal players. Thirteen players (24.1 ± 3.7 years) performed a testing battery (countermovement jump (CMJ), Illinois agility and YoYo intermittent recovery test level 1 (YYIR1)) preceded by 15 min of PBMT (1 min 30 s each muscular point; five muscular points in each lower limbs) or 15 min of placebo (SHAM), in a counterbalanced randomized cross-over design (one-week in-between PBMT/SHAM). All test performance did not differ (p > 0.05) between PBMT and SHAM, as well as blood lactate, rating of perceived exertion, heart rate, and muscle oxygenation (via near infrared spectroscopy) responses. The acute application of PBMT prior to a physical testing battery does not influence high-intensity and intermittent exercises performance, neither physiological nor perceptual responses in amateur female futsal players.


Life ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 586
Author(s):  
Ronam Toledo ◽  
Marcelo R. Dias ◽  
Ramon Toledo ◽  
Renato Erotides ◽  
Daniel S. Pinto ◽  
...  

The purpose of the present study was to compare the heart rate (HR), blood lactate and training load between different CrossFit® workouts, with equalized total work volumes in men and women. The study included 23 individuals (13 men and 10 women) experienced in CrossFit® training, who performed two workouts with different training types (as many reps as possible (AMRAP) and ‘for time’) but an equalized volume. Measurements of lactate, HR and rating of perceived exertion (RPE) were performed. The results show that there was no HR interaction between workout time and sex (p = 0.822; η2 = 0.006) and between workout type and sex (p = 0.064, η2 = 0.803). The HR significantly differed during each workout type (p < 0.001, η2 = 0.621), but not between the two workout types (p = 0.552, η2 = 0.017). Lactate showed no difference between the workout types (p = 0.474, η2 = 0.768), although the training load was higher (p = 0.033, η2 = 0.199) in women when they performed AMRAP. Altogether, the HR was not significantly different between training types or sex, while RPE, lactate and training load showed statistically significant differences depending on the group (women or men) or workout type (AMRAP or ‘for time’).


1996 ◽  
Vol 8 (4) ◽  
pp. 337-350 ◽  
Author(s):  
Kevin L. Lamb

This study examined the validity and reliability of the Rating of Perceived Exertion (RPE) scale and the Children’s Effort Rating Table (CERT) as methods of regulating exercise intensity during discontinuous cycle ergometry. Sixty-four school children (ages 9–10) were randomly assigned to one of two groups, RPE or CERT, and received two trials 7 days apart. On both occasions, subjects produced 4 × 4-min scale-specific exercise intensities—3, 5, 7, and 9 (CERT) or 8, 12, 15, and 18 (RPE)—interspersed with 2-min rest periods. Analyses yielded significant (p < .01) correlations between perceived effort levels and objective measures: r = .47 to .61 (heart rate) and r = .59 to .75 (power output). Intraclass correlations indicated satisfactory overall repeatability of the produced exercise intensities (R > .70), but some notable inconsistencies were observed. The usefulness of effort perception scales among preadolescent children is presently rather limited, probably due to a number of confounding factors that need to be systematically addressed.


2014 ◽  
Vol 114 (3) ◽  
pp. 854-865 ◽  
Author(s):  
Marcus W. Kilpatrick ◽  
Samuel J. Greeley

The purpose of this study was to assess the effect of sprint interval training on rating of perceived exertion. 20 healthy participants (11 men, 9 women; M age = 23 yr.) completed a maximal cycle ergometer test and two high-intensity interval training cycling sessions. Each session utilized the same work-to-rest ratio (1:1), work intensity (90% max), recovery intensity (10% work intensity), and session duration (16 min.). Trials differed on duration of the interval segment, with a 30-sec. trial and a 60-sec. trial. Sessions required the same amount of total work over the duration of the trial. Rating of perceived exertion assessed before, during, and after exercise were higher for the 60-sec. trial than the 30-sec. trial despite no difference in total work. High intensity interval training trials utilizing the same total external work but differing in interval length produced different ratings of perceived exertion. Perceived exertion is significantly higher for sessions of exercise that utilize longer work intervals. These findings suggest that shorter intervals may produce more favorable exertional responses that could positively affect future behavior.


Author(s):  
Ciaran O’Grady ◽  
Louis Passfield ◽  
James G. Hopker

Purpose: Rating of perceived exertion (RPE) as a training-intensity prescription has been extensively used by athletes and coaches. However, individual variability in the physiological response to exercise prescribed using RPE has not been investigated. Methods: Twenty well-trained competitive cyclists (male = 18, female = 2, maximum oxygen consumption =55.07 [11.06] mL·kg−1·min−1) completed 3 exercise trials each consisting of 9 randomized self-paced exercise bouts of either 1, 4, or 8 minutes at RPEs of 9, 13, and 17. Within-athlete variability (WAV) and between-athletes variability (BAV) in power and physiological responses were calculated using the coefficient of variation. Total variability was calculated as the ratio of WAV to BAV. Results: Increased RPEs were associated with higher power, heart rate, work, volume of expired oxygen (VO2), volume of expired carbon dioxide (VCO2), minute ventilation (VE), deoxyhemoglobin (ΔHHb) (P < .001), and lower tissue saturation index (ΔTSI%) and ΔO2Hb (oxyhaemoglobin; P < .001). At an RPE of 9, shorter durations resulted in lower VO2 (P < .05) and decreased ΔTSI%, and the ΔHHb increased as the duration increased (P < .05). At an RPE of 13, shorter durations resulted in lower VO2, VE, and percentage of maximum oxygen consumption (P < .001), as well as higher power, heart rate, ΔHHb (P < .001), and ΔTSI% (P < .05). At an RPE of 17, power (P < .001) and ΔTSI% (P < .05) increased as duration decreased. As intensity and duration increased, WAV and BAV in power, work, heart rate, VO2, VCO2, and VE decreased, and WAV and BAV in near-infrared spectroscopy increased. Conclusions: Self-paced intensity prescriptions of high effort and long duration result in the greatest consistency on both a within- and between-athletes basis.


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