This study examined the kinetic and kinematic differences between accentuated eccentric loading (AEL) and cluster sets in trained male subjects (age = 26.1 ± 4.1 years, height = 183.5 ± 4.3 cm, body mass = 92.5 ± 10.5 kg, and back squat to body mass ratio = 1.8 ± 0.3). Four load condition sessions consisted of traditionally loaded (TL) “straight sets,” TL cluster (TLC) sets, AEL cluster (AEC) sets, and AEL “straight sets” where only the first repetition had eccentric overload (AEL1). An interrepetition rest interval of 30 seconds was prescribed for both TLC and AEC. Concentric intensity for all load conditions was 80% 1 repetition maximum (1RM). Accentuated eccentric loading was applied to repetitions using weight releasers with total eccentric load equivalent to 105% of concentric 1RM. Traditionally loaded cluster had statistically greater concentric outputs than TL. Furthermore, statistically greater eccentric and concentric outputs were observed during AEC compared with TL with the exception of peak power. Statistically greater concentric characteristics were observed in TLC compared with AEL1, but statistically greater eccentric outputs were observed in AEL1. In the 2 cluster set conditions, statistically greater concentric rate of force development (RFDCON) (d = 0.470, p < 0.001) and average velocity (vavg) (d = 0.560, p < 0.001) in TLC compared with AEC were observed. However, statistically greater eccentric work (WECC) (d = 2.096, p < 0.001) and eccentric RFD (RFDECC) (d = 0.424, p < 0.001) were observed in AEC compared with TLC. Overall, eccentric overload demonstrated efficacy as a means of increasing eccentric work and RFD, but not as a means of potentiating concentric output. Finally, interrepetition rest seems to have the largest influence on concentric power output and RFD.

This study examined the kinetic and kinematic differences between accentuated eccentric loading (AEL) and cluster sets in trained male subjects (age = 26.1 ± 4.1 years, height = 183.5 ± 4.3 cm, body mass = 92.5 ± 10.5 kg, and back squat to body mass ratio = 1.8 ± 0.3). Four load condition sessions consisted of traditionally loaded (TL) “straight sets,” TL cluster (TLC) sets, AEL cluster (AEC) sets, and AEL “straight sets” where only the first repetition had eccentric overload (AEL1). An interrepetition rest interval of 30 seconds was prescribed for both TLC and AEC. Concentric intensity for all load conditions was 80% 1 repetition maximum (1RM). Accentuated eccentric loading was applied to repetitions using weight releasers with total eccentric load equivalent to 105% of concentric 1RM. Traditionally loaded cluster had statistically greater concentric outputs than TL. Furthermore, statistically greater eccentric and concentric outputs were observed during AEC compared with TL with the exception of peak power. Statistically greater concentric characteristics were observed in TLC compared with AEL1, but statistically greater eccentric outputs were observed in AEL1. In the 2 cluster set conditions, statistically greater concentric rate of force development (RFDCON) (d = 0.470, p < 0.001) and average velocity (vavg) (d = 0.560, p < 0.001) in TLC compared with AEC were observed. However, statistically greater eccentric work (WECC) (d = 2.096, p < 0.001) and eccentric RFD (RFDECC) (d = 0.424, p < 0.001) were observed in AEC compared with TLC. Overall, eccentric overload demonstrated efficacy as a means of increasing eccentric work and RFD, but not as a means of potentiating concentric output. Finally, interrepetition rest seems to have the largest influence on concentric power output and RFD.

This dissertation was 2 parts of investigations of various acute responses to high-volume combined accentuated eccentric loading and rest redistribution (AEL + RR). Resistance-trained men (n = 12, 25.6 ± 4.4 years, 1.77 ± 0.06 m, 81.7 ± 11.4 kg) completed a back squat (BS) 1 repetition maximum (1RM) and weight releaser familiarization session. Three BS exercise conditions (sets × repetitions × eccentric/concentric loading) comprised AEL + RR 5: 3 × (5 × 2) × 110/60%, AEL + RR 2: 3 × (2 × 5) × 110/60%, and traditional sets (TS): 3 × (1 × 10) × 60/60% 1RM. The AEL + RR 5 resulted in significantly (p < 0.05) greater concentric peak velocity (PV) (1.18 ± 0.17 m∙s–1) and power (PP) (2,304 ± 499 W) compared to AEL + RR 2 (1.11 ± 0.19 m∙s–1 and 2,148 ± 512 W) and TS (1.10 ± 0.14 m∙s–1 and 2,079 ± 388 W). Furthermore, AEL + RR 5 resulted in significantly greater PV and PP across all 10 repetitions compared to TS. Although AEL + RR 5 resulted in significantly greater concentric mean force (MF) (1,706 ± 224 N) compared with AEL + RR 2 (1,697 ± 209 N) and TS (1,685 ± 211 N), no condition by set or repetition interactions were found. The AEL + RR 5 yielded greater total volume load (sets × repetitions × eccentric + concentric loading) (6630.1 ± 1210.4 kg) compared with AEL + RR 2 (5944.3 ± 1085.2 kg) and TS (5487.0 ± 1001.7 kg). The AEL + RR 5 led to significantly (p < 0.05) greater rating of perceived exertion (RPE) after set 2 and 3 and lower blood lactate (BL) after set 3, 5-, 15-, and 25-minute post-exercise than AEL + RR 2 and TS. There was a main effect of condition for BL between AEL + RR 5 (5.11 ± 2.90 mmol∙L–1), AEL + RR 2 (6.23 ± 3.22 mmol∙L–1), and TS (6.15 ± 3.17 mmol∙L–1). In summary, AEL + RR 5 results in unique acute mechanical, physiological, and perceptual responses in high-volume BS exercise.

The current investigation was an examination of the repetition-to-repetition magnitudes and changes in kinetic and kinematic characteristics of the back squat using accentuated eccentric loading (AEL) and cluster sets. Trained male subjects (age = 26.1 ± 4.1 years, height = 183.5 ± 4.3 cm, body mass = 92.5 ± 10.5 kg, back squat to body mass ratio = 1.8 ± 0.3) completed four load condition sessions, each consisting of three sets of five repetitions of either traditionally loaded straight sets (TL), traditionally loaded cluster sets (TLC), AEL cluster sets (AEC), and AEL straight sets where only the initial repetition had eccentric overload (AEL1). Eccentric overload was applied using weight releasers, creating a total eccentric load equivalent to 105% of concentric one repetition maximum (1RM). Concentric load was 80% 1RM for all load conditions. Using straight sets (TL and AEL1) tended to decrease peak power (PP) (d = −1.90 to −0.76), concentric rate of force development (RFDCON) (d = −1.59 to −0.27), and average velocity (MV) (d = −3.91 to −1.29), with moderate decreases in MV using cluster sets (d= −0.81 to −0.62). Greater magnitude eccentric rate of force development (RFDECC) was observed using AEC at repetition three (R3) and five (R5) compared to all load conditions (d = 0.21–0.65). Large within-condition changes in RFDECC from repetition one to repetition three (∆REP1–3) were present using AEL1 (d = 1.51), demonstrating that RFDECC remained elevated for at least three repetitions despite overload only present on the initial repetition. Overall, cluster sets appear to permit higher magnitude and improved maintenance of concentric outputs throughout a set. Eccentric overload with the loading protocol used in the current study does not appear to potentiate concentric output regardless of set configuration but may cause greater RFDECCcompared to traditional loading

The current investigation was an examination of the kinetic and kinematic characteristics of the back squat using accentuated eccentric loading (AEL) and cluster set programming strategies. Trained male subjects (age = 26.1 ± 4.1 years, height = 183.5 ± 4.3 cm, body mass = 92.5 ± 10.5 kg, back squat to body mass ratio = 1.8 ± 0.3) volunteered to complete four different load condition sessions involving traditionally loaded straight sets (TL), traditionally loaded cluster sets (TLC), AEL cluster sets (AEC), and AEL straight sets where only the first repetition of each set used eccentric overload (AEL1). The use of AEL increased eccentric work (WECC) and eccentric rate of force development (RFDECC) but did not result in the expected potentiation of subsequent concentric output. Interrepetition rest, however, appears to have the largest influence on concentric peak power (PP), rate of force development (RFDCON), and average velocity (MV). Additionally, the current study was an investigation of the efficacy of novel methods of ultrasonography technique that can be applied to monitoring training response. Compared to lying measures of the vastus lateralis (VL), standing ultrasonography measures of muscle thickness (MT), pennation angle (PA), and cross-sectional area (CSA) were more strongly and abundantly correlated with dynamic and isometric strength performance. Finally, the present study was an exploration of the genetic underpinnings of performance outcomes and muscle phenotypic characteristics. The polymorphisms of two candidate genes (ACTN3, ACE) typical of strength-power athletes were used. ACTN3 RR tended to result in greater type II fiber CSA and alter maximal strength, while ACE DD tended to influence RFD through the presence of more favorable type II-to-type I CSA ratios. Overall, the current investigation provided valuable insight into the characteristics of advanced programming tactics. Furthermore, the ultrasonography measurement and genetic aspects of the current investigation may serve as a framework to inform monitoring practice and generate hypotheses related to the training process.

Syfte och frågeställning Syftet med denna studie är att identifiera effekten av svänghjulsträning på styrkerelaterade variabler som påverkar idrottslig prestation genom en sammanställning av befintlig vetenskaplig litteratur. Studiens frågeställning var: (1) Vilken effekt har svänghjulsträning på muskeltillväxt (hypertrofi)? (2) Vilken effekt har svänghjulsträning på utvecklingen av maximal styrka? (3) Vilken effekt har svänghjulsträning på utvecklingen av Power (effektutveckling)? (4) Vilken effekt har svänghjulsträning på horisontell förflyttning? (5) Vilken effekt har svänghjulsträning på vertikal förflyttning? Metod En metaanalys för 15 experimentella studier som uppfyllt urvalskriterierna genomfördes. De inkluderade studierna kvalitetsgranskades med Pedros skala. För att möjliggöra en sammanställning av samtliga resultat analyserades resultaten i dataprogrammet Review Manager version 5.3 med Random effekt modell och presenteras med Forest plots. Jämförelserna gjordes över en period på 4-24 veckor. Resultat Svänghjulsträning under en period av 4-24 veckor visar på en statistisk signifikant utveckling  av muskulär hypertrofi (effektstorlek 0,68), maximal styrka (1,40), Power (1,0), horisontell (0,54) och vertikal förflyttning (0,60). Slutsats Det finns stöd i litteraturen för att friska individer presterar bättre på så väl dynamiska styrketest som funktionella test efter svänghjulsträning. Evidensen är särskilt stark för att svänghjulsträning utvecklar maximal styrka och Power för tränade yngre individer samt i kortare mer intensiva block. Denna metaanalys har bara sammanställt skillnader i prestation före och efter svänghjulsträning och kan därför inte säga om effekten av svänghjulsträning är större än effekten av upprepade mätningar eller annan träning. / Aim The aim of this study was to identify the effect of the flywheel training on strength-related variables that affect athletic performance by compiling existing scientific literature. Research questions: (1) What effect does flywheel training have on muscle growth (hypertrophy)? (2) What effect does flywheel training have on the development of maximum strength? (3) What effect does flywheel training have on the development of Power (effect development)? (4) What effect does flywheel training have on the development of horizontal movement? (5) What effect does flywheel training have on the development of vertical movement? Method A meta-analysis was conducted from 15 experimental studies that met the selection criteria. The quality of included studies was reviewed by Pedro scale. In order to identify possible bias in the selection process a Funnel plot was carried out. To enable the compilation of all results an analyze with Random effect model was carried out with software Review Manager Version 5.3 and presented with Forest plots. Comparisons were made over a period of 4-24 weeks. Results Flywheel training for a period of 4-24 weeks show a statistically significant increase in effect size for muscular hypertrophy (0,49), maximum strength (1,40), Power (1,00), horizontal-(0,54) and vertical movement (0,60). Conclusions There's support in published studies that healthy individuals perform better on dynamic strength tests as wells as functional test after flywheel training. The evidence is particularly strong that flywheel training develops maximum strength and Power in trained younger individuals and in shorter more intensive blocks. This meta-analysis has just compiled the differences in performance before and after flywheel training and therefore cannot say if the effect of flywheel training is greater than the effect of repeated measurements or other exercise.

I denna översiktsartikel granskades 17 randomiserade kontroll studier som undersökt hur excentrisk träning har påverkat hopphöjd, muskelstyrka och effektutveckling hos tränade och skadefria individer, med mål att svara på följande två frågeställningar; 1) ”Är excentrisk träning ett effektivt sätt att träna för att utveckla hopphöjd, muskelstyrka och effektutveckling för tränade och skadefria individer?” 2) ”Om det är det, hur bör denna träning i så fall se ut?”. Majoriteten av insamlade studier kunde inte urskilja några signifikanta förändringar till följd av excentrisk träning. Endast sex av 17 studier kunde påvisa akuta såväl som kortsiktiga signifikanta förbättringar av hopphöjd, muskelstyrka och effektutveckling. Dock ifrågasätts relevansen av dessa fynd då effektstorleken inte rapporterats i alla studier samt att utformningen av studierna varierat från en studie till en annan. Sammantaget lyckades inte de granskade studierna bevisa att excentrisk träning är en effektiv metod för att utveckla hopphöjd, muskelstyrka och effektutveckling hos tränade och skadefria individer. / In this review 17 randomized control studies were reviewed that had examined the effects of eccentric training regarding jump height, strength and power for trained and non-injured individuals. The purpose of the review was to answer the following two questions at issue; 1) “Is eccentric training an efficient method to enhance jump height, strength or power for trained and non-injured individuals?” 2) “If so, how should that training regime be designed?”. Most of the included studies could not distinguish any significant changes because of eccentric training. Only six out of 17 studies could show acute as well as short term significant improvements in jump height, strength and power. The relevance of these findings is questioned since effect size has not been reported in all the included studies. The variety between the different interventions in each study also makes it difficult to compare the results between one study and another. In conclusion, the reviewed studies failed to show that eccentric training is an effective method to enhance jump height, strength and power for trained and non-injured individuals.