1,721,085 research outputs found
Muscle damage, repeated bout effect and training induced changes by different eccentric training modalities
Full text linkAbstract1
È provato che la contrazione eccentrica induca danno muscolare e successivo adattamento, il repeated bout effect. Essa può essere eseguita in modalità isotonica o isocinetica. Scopo dello studio è misurare e confrontare il danno muscolare e il successivo adattamento nelle 2 modalità.
30 maschi sono stati assegnati alla modalià isocinetica (IK) o isotonica (IT). Le misure sono state eseguite prima, immediatamente dopo e fino a 4 giorni dopo 60 contrazioni eccentriche sovra massimali. Concentrazione di CK, perdita di forza e dolore sono stati utilizzati come markers di danno. Lo stesso protocollo è stato ripetuto dopo 4 settimane.
Rispetto al basale, sia IK che IT hanno aumentato i markers di danno dopo il primo allenamento, mostrando significativi miglioramenti dopo il secondo allenamento. Dopo il primo allenamento, rispetto a IK, IT mostrava valori più alti di CK (+30±13%), maggiore perdita di forza(+40±14%) e dolore(+34±8%), p<0,05 per tutti i parametri. Dopo il second allentamento, rispetto a IK, IT mostrava simile CK (+12±4%, n.s.), maggior perdita di forza(+24±4%, p<0,05) e simile dolore (+10%±5%, n.s.).
Dopo il primo allenamento sia IK che IT hanno mostrato sintomi di danno, che in entrambi sono diminuiti dopo il secondo. IT ha causato un danno maggiore, portando comunque ad una maggiore protezione. Questo può essere dovuto a fattori neurali o meccanici.
Abstract2
L’allenamento eccentric (ECC) risulta avere migliori risultati rispetto al concentrico su forza, massa muscolare ed effetto crociato. In letteratura si trova maggiormente allenamento isocinetico (IK), mentre di solito in campo o palestra si usa un movimento di tipo isotonico (IT). Scopo dello studio è confrontare gli effetti di IK e IT dopo allenamento eccentrico su forza e massa muscolare.
49 maschi sani sono stati divisi in IK, IT e gruppo di controllo(CG). Entrambi i gruppi di allenamento hanno eseguito 50 ripetizioni eccentriche unilaterali di estensione del ginocchio al 120% isocinetico o isotonico, per un totale di 14 sedute in 6 settimane. Forza, massa e architettura muscolare sono state misurate prima e dopo l’allenamento.
Rispetto CG, IK ha mostrato ha aumentato 1RM (12%, CI95% 6 to 19%), picco concentrico (15%, 8 to 22%), eccentrico (35%, 25 to 45%) ed isometrico (25%, 18 to 34%) (P<0.001). Rispetto a CG, IT ha aumentato 1RM (14%, 9 to 20%),picco concentrico (17%, 11 to 24%), eccentrico (25%, 16 to 34%) ed isometrico (22%, 15 to 29%) (P<0.001). Nessuna differenza tra IK e IT in 1RM (2%, -3 to 7%), picco concentrico (-2%, -4 to 8%) ed isometrico (-3%, -8 to 3%). Solo il picco eccentrico era maggiore in IK rispetto a IT (8%, 1 to 14%). Nessuna differenza nella massa muscolare.(0.419<P<0.769). L’arto non allenato ha migliorato la forza in entrambi i gruppi.
L’allenamento eccentrico ha migliorato la forza, senza cambiamenti di massa muscolare, portando a pensare che gli adattamenti siano stati di tipo neurali. IK e IT hanno mostrato effetti simili, mostrando che l’allenamento eccentrico porta effetti rapidi sulla forza.
Abstract3
L’allenamento eccentrico provoca danno muscolare, che però viene ridotto dopo una seconda sessione, on, i.e.: repeated bout effect. Lo scopo dello studio è valutare il danno muscolare e successive adattamento prodotto da allenamento eccentrico con tecnologia inerziale.
12 uomini hanno eseguito 100 ripetizioni di squat inerziale.Prima, immediatamente dopo e fino a 4 giorni dopo l’allenamento sono stati misurati la concentrazione ematica di CK, forza del quadricipite, dolore muscolare e performance di salto. Lo stesso protocollo è stato ripetuto dopo 3 settimane.
Rispetto al basale,dopo la prima sessione, CK e dolore sono aumentati rispettivamente fino a 3 e 4 giorni, mentre la forza ed il salto sono peggiorati solo immediatamente dopo l’allenamento. Tuttavia, dopo il secondo allenamento tutti i sintomi di danno erano significativamente inferiori.
Si può concludere che l’allenamento inerziale riflette le caratteristiche dell’allenamento eccentrico, provocando danno muscolare e protezione dopo 3 settimane. Fattori neurali possono aver influenzato la forza e la performance di salto, facendo in modo che non fossero eccessivamente intaccati dal danno.
Abstract4
L’allenamento con squat eseguito con modalità inerziale è abbinato ad aumenti di forza e massa muscolare. Lo scopo dello studio è verificare se esistono transfer nella performance sportiva, confrontandolo con un classico allenamento da campo.
45 maschi sani attivi sono stati divisi in chi si allenava con squat inerziale (IS), squat jump con sovraccarico (WSJ) o controllo (CG). Prima e dopo 16 sessioni in 8 settimane, ognuna delle quail consistava in 60 ripetizioni massimali, sono stati misurati la forza degli estensori e flessori del ginocchio, la massa muscolare degli arti inferiori, l’architettura del quadricipite, altezza di salto, tempo su 30 metri, 20m navetta e du un test di cambio di direzione.
Rispetto a CG, la forza degli estensori del ginocchio è aumentata in misura simile in IS e WSJ, mentre solo il primo ha aumentato la forza dei flessori. La massa muscolare e la lunghezza del fascicolo sono aumentati più in IS che in WSJ, così come l’altezza di salto. Miglioramenti simili si sono avuti nei 20m navetta e 30m , mentre il test di cambio direzione è migliorato solo in WSJ.
Questi dati suggeriscono che l’allenamento inerziale può essere usato con successo per aumenti di performance, confermando la letteratura sugli aumenti di forza e massa muscolare. Inoltre, esso si può alternare con un allenamento tradizionale.
Abstract5
L’allenamento con sovraccarichi è classicamente eseguito usando sia la contrazione concentrica(CONC) che eccentrica(ECC) , ossia (i.e.: CONC+ECC). Tuttavia, ECC consente di avere miglioramenti maggiori di forza e struttura muscolare. Inoltre, eseguita unilateralmente, si hanno miglioramenti di forza sull’arto non allenato.Infine, dopo un periodo di de allenamento, in letteratura si hanno prove di mantenimento dei valori di forza ottenuti dopo un allenamento. Scopo dello studio è confrontare diverse metodiche di allenamento misurando cambiamenti di forza, massa ed architettura muscolare dopo un period di allenamento e di deallenamento. In aggiunta, si vuole definire le stesse misure sull’arto non allenato.
60 donne sono state divise in CONC, ECC, CONC+ECC or control group (CONTR). L’allenamento è stato equivolumetrico, consistito in 7 settimane allenamento unilaterale del muscolo quadricipite, seguite da 4 settimane di deallenamento. Prima dell’inizio, dopo la fine e dopo 4 settimane dalla fine dell’allenamento sono state misurate la forza del quadricipite, la sua massa muscolare e la sua architettura. Le misure sono state eseguite su entrambe le gambe.
Dopo il periodo di allenamento, tutti i gruppi hanno aumentato la forza del quadricipite, mentre solo ECC ha aumentato il picco eccentrico. La massa muscolare non è cambiata in nessun gruppo, mentre varie modifiche ci sono state nella lunghezza del fascicolo, nel suo spessore e nell’angolo di pennazione. Della gamba allenata. L’arto non allenato(UT) ha mostrato miglioramenti di forza specifici con la contrazione eseguita, senza aumenti di massa muscolare, ma con piccolo modifiche di architettura. Dopo 4 settimane, la forza ha continuato ad aumentare sia nell’arto allenato che in UT, la massa magra è aumentata solo in ECC nell’arto allenato, mentre l’architettura muscolare ha subito ulteriori modifiche, soprattutto nell’arto allenato.
Si può concludere che quando il volume di allenamento è simile, gli aumenti di forza sono simili, pur rispettando la specificità del tipo di contrazione eseguita. Nell’arto allenato le modifiche architettoniche hanno contribuito ad aumentare la forza, mentre nell’arto non allenato si può parlare di effetti neurali. Il periodo di inattività, volutamente breve, va inteso come continuazione del processo di supercompensazione.Eccentric contraction has been proved to be different from concentric contraction. Lengthening contraction can be performed using isotonic , isokinetic or inertial devices. Aim of the thesis is to describe different eccentric contraction modalities studying main phenomenon related to them. Five studies will be presented to analyze muscle damage, repeated bout effect, training and detraining induced changes.
Abstract1
Lengthening contraction is well known to induce muscle injury and it confers protection to a subsequent eccentric session, i.e. repeated bout effect. Dynamic negative action can be performed resisting to an external load (e.g.: isotonic) or using isokinetic device. Aim of the study is to measure muscle damage and repeated bout effect induced by both lengthening exercise modalities.
Thirty males were randomly assigned to isokinetic(IK) or isotonic(IT) group and they tested at baseline, immediately after and up to 4 days after 60 supra maximal eccentric contractions. CK activity, strength loss and muscle soreness were taken as indirect markers of muscle damage. Same protocol was repeated after 4 weeks.
Compared to baseline, IK and IT resulted in augmented injury symptoms after first bout. Compared to first bout, second bout resulted in significantly lower muscle damage both in IK and IT. After first bout, compared to IK, IT showed increased CK activity (+30±13%), higher strength loss(+40±14%) and greater soreness (+34±8%), p<0,05 for all parameters. After second bout, compared to IK, IT showed similar CK activity (+12±4%, n.s.), higher strength loss (+24±4%, p<0,05) and similar soreness (+10%±5%, n.s.).
Both IK and IT induced muscle damage after first bout. Second bout resulted in less damage for both IK and IT. IT induced significantly greater damage compared to IK, but it confers more protection after second bout. It is concluded that neural and mechanical factor influenced difference between IK and IT eccentric induce damage.
Abstract2
Eccentric (ECC) training has been shown to induce greater effect than concentric training on strength, muscle mass and contra lateral adaptations. The majority of the studies have used isokinetic (IK) devices for investigating the acute and chronic effects of ECC training. However, isotonic (IT) apparatuses are more commonly available in sport setting. Aim of the study was to compare ISOK to ISOT ECC training by assessing the effects on muscle strength and mass.
Forty-nine healthy sport science students have been randomly divided in 3 groups: IK, IT, and control group (CG). Both training groups performed 50 ECC repetitions of knee extension at 120% of their maximal strength measured in concentric modality (1RM for IT and peak concentric torque for IK), for a total of 14 times in 7 weeks. Isometric maximal voluntary contraction (MVC), concentric and eccentric strength, 1RM, muscle mass and architectural alterations have been measured pre and post training.
Compare to CG, the IK group showed higher 1RM (12%, CI95% 6 to 19%), concentric (15%, 8 to 22%), eccentric (35%, 25 to 45%) and isometric (25%, 18 to 34%) maximal strength (P<0.001). Compare to CG, IT showed higher 1RM (14%, 9 to 20%), concentric (17%, 11 to 24%), eccentric (25%, 16 to 34%) and isometric (22%, 15 to 29%) maximal strength (P<0.001). No differences between ISOK and ISOT were found in 1RM (2%, -3 to 7%), concentric (-2%, -4 to 8%) and isometric (-3%, -8 to 3%) maximal strength. Only eccentric strength was higher in the IK compare to the IT group (8%, 1 to 14%). No differences between groups were found in muscle mass (0.419<P<0.769). Untrained limb improve strength in both training groups.
Eccentric training improved muscle peak torque and 1RM in physically active people. Data showed that neural adaptation is the main factor increasing muscle strength, while muscle mass apparently was not strictly related to it. IK and IT showed similar training effects. This study displayed that ECC training induced early strength adaptations.
Abstract3
Muscle damage is proved to occur after eccentric training. Moreover, it confers protection to a subsequent session, i.e.: repeated bout effect. Aim of the study is evaluate if lengthening contraction enhanced by inertial flywheel squat will cause symptoms of muscle injury and following protection.
Twelve healthy amateurs males performed 100 maximal squat repetitions using inertial device. At baseline, after training and up to 4 days after CK blood concentration, Knee extensors strength, muscle soreness and jump performance were measured as markers of muscle damage. Same protocol was repeated after 3 weeks.
Compare to baseline, CK and muscle soreness increase respectively up to 3 and 4 days, while strength loss and jump height were affected only post training. The second bout revealed significant markers decrement.
Inertial flywheel squat induce classical symptoms of muscle injury, even if strength loss and performance could be positively influenced by neural patterns. Eccentric overload does protect muscle at least up to 3 weeks.
Abstract4
Inertial flywheel squat has been proved to increment strength and muscle mass. Aim of the study is to measure transfer in performance, comparing it with a traditional field training.
Forty five healthy males underwent to inertial squat (IS) or weighted squat jump (WSJ) or control group. (CG) Before and after 16 sessions of 60 repetition knee extensors and flexors torque, lower limbs lean mass, quadriceps architecture, jump height, 30m dash, 20m shuttle and changing direction ability were tested.
Compare to CG, Knee extensors torque increased similarly in IS and WSJ, while only former improved knee flexors strength. Muscle muscle mass and fascicle length augmented more in IS than WSJ, as well as jump. Similar improvements occurred in 20m shuttle and 30m dash, while changing direction ability improved only in WSJ.
These data showed that both IS and WSJ are adequate stimuli to improve strength, and they should be used in sport with a great power development
Abstract5
Resistance training is classically performed dynamically using both concentric(CONC) and eccentric(ECC) phases (i.e.: CONC+ECC). However, muscle strength and structure gain has been proved superior when E was enhanced. In addition, when performed unilaterally, force has been shown to improve also in untrained limb. Finally after detraining period, adaptations are often retained. Therefore aim of the study is to compare different exercise methods measuring strength, mass and architecture after training and a short detraining. In addition we want to evaluate contra lateral effect and its time course.
Sixty women have been randomly divided in CONC, ECC, CONC+ECC or control group (CONTR). Training groups performed 7 weeks of equivolumetric unilateral knee extension, followed by 4 weeks of detraining. Maximal voluntary concentric, eccentric and isometric contraction, 1RM, muscle mass and muscle architecture were measured at baseline, after training and after detraining period. Measurements were performed on both legs.
After training, all groups improved concentric, isometric and 1RM compared to baseline, while eccentric torque was greater only in ECC. Muscle mass showed no increment, while fascicle length, fascicle thickness and pennation angle changed dissimilarly in each group. Untrained leg (UT) showed task related strength improvement, without affecting muscle mass, but with changes in muscle architecture. After 4 weeks, strength continued to increase in both in trained and UT, muscle mass was higher only in ECC, while muscle architecture showed further adaptations
COMPARISON OF THE EFFECTS OF ISOKINETIC VS ISOTONIC ECCENTRIC TRAINING ON MUSCLE STRENGTH AND MASS.
No full textIntroduction
Eccentric (ECC) training has been shown to induce higher improvements than concentric training on muscle strength and mass (Roig, 2009). The majority of the studies have used isokinetic (ISOK) dynamometers for investigating the acute and chronic effects of ECC training. However, isotonic (ISOT) devices are more commonly available in real sport setting. Aim of the study was to compare ISOK to ISOT ECC training by assessing the effects on muscle strength and mass.
Methods
Forty-nine healthy sport science students were randomly divided in 3 groups: isokinetic eccentric training (ISOK, n=14), isotonic eccentric training (ISOT, n=17) and control group (CON, n=18). Both training groups performed 50 ECC repetitions of knee extension at 120% of their maximal strength measured in concentric modality (1RM for ISOT and peak concentric torque for ISOK), for a total of 14 times in 6 weeks. Isometric maximal voluntary contraction (MVC), concentric and eccentric strength at 60 °/s, 1RM, and muscle mass (using DEXA) were measured pre and post training. All dependent variables were analyzed after log transformation using ANCOVA, entering the baseline values as covariate and factor “group” as independent variable.
Results
Compare to CON, the ISOK group showed higher 1RM (12%, CI95% 6 to 19%), concentric (15%, 8 to 22%), eccentric (35%, 25 to 45%) and isometric (25%, 18 to 34%) maximal strength (P<0.001). Compare to CON, ISOT showed higher 1RM (14%, 9 to 20%), concentric (17%, 11 to 24%), eccentric (25%, 16 to 34%) and isometric (22%, 15 to 29%) maximal strength (P<0.001). No differences between ISOK and ISOT were found in 1RM (2%, -3 to 7%), concentric (-2%, -4 to 8%) and isometric (-3%, -8 to 3%) maximal strength. Only eccentric strength was higher in the ISOK compare to the ISOT group (8%, 1 to 14%). No differences between groups were found in muscle mass (0.419<P<0.769).
Discussion
This study showed that ECC training using both ISOK and ISOT improved maximal strength in physically active people. The lack of muscle mass changes suggests that the increase in muscle strength waw mainly due to neural adaptations (Hortobagyi, 1996). ISOK showed higher improvement in ECC strength measured on the isokinetic dynamometer but this may be due to similarity between testing and training conditions. Nevertheless, considering ISOT devices are more easily available this training modality seems to be a good alternative to ECC training using isokinetic dynamometers.
References
Roig et al., 2009, Br J Sports Med 43(8): 556-68.
Hortobágyi et al., J Appl Physiol. 1996 Oct;81(4):1677-82
Analysis of correlation between core stability and performance
No full textIt’s known that core ability is involved in power exercises, allowing strength transfer from trunk to distal limbs (Sharrock, 2011). Aim of the study was to identify whether core stability can influence sports performance. Fifty healthy students (30 males and 20 females; age: 20.6 ± 1.4 years; height 174.8 ± 8.6 cm; weight 68.1 ± 13.4 kg) performed twice the following tests. The independent variables were maximal isometric endurance positions using McGill test (MG): Back Extension (BE), Trunk Flexion (TF), Right Bridge (RB), Left Bridge (LB) (Nesser 2008). The dependent variables were Standing Long Jump (SLJ), Star Excursion Balance Test (SEBT), Medicine Ball Throw with crossed legs, in standing and in dynamics (MBT1, MBT2, MBT3) and Accuracy of a tennis ball Throwing, executed with previous described modalities (AT1, AT2, AT3). Statistical software (SPSS 16.0; Chicago, ILL) was used to perform statistical analyses. In order to test measurements reliability, Intra Class Coefficient (Cronbach α) was used with all data. Relationships between dependent and indipendent variables, as well as inter dependent variables were determined using multiple bivariate correlations, represented by Pearson correlation coefficient. Statistical significance was set at p≤0.05. Significant correlations were found between RB and SLJ (r=0.440), MTB1 (r=0.508), MBT2 (r=0.495), MBT3 (r=0.473) and AT3, considering simultaneously both sprint time and the score of the launch (r=-0.288); between LB and SLJ (r=0.533), the three modalities to execute the MBT (r=0.504, r=0.481, r=0.489) and AT3 (r=-0.281); finally, between MG and SLJ (r=0.290), and MBT1 (r=0.325). In the light of the data we obtained, it is possible to suggest that training of trunk stability muscles can bring benefits improving long jump, throwing and toss accuracy in dynamic conditions, typical team sports tasks .
Sharrock C et al, Int J Sport Phys Ther, 2011, 6(2): 63-74
Nesser TW et al., J Strength Cond Res, 2008, 22(6): 1750-5
Muscle damage and repeated bout effect induced by enhanced-eccentric squat exercise
No full textAIM: Muscle damage and repeated bout effect have been studied after pure eccentric-only exercise. The aim of this study was to evaluate muscle damage and repeated bout effect induced by enhanced-eccentric squat exercise using flywheel device.METHODS: Thirteen healthy males volunteered for this study. Creatine-kinase blood activity (CK), quadriceps isometric peak torque and muscle soreness were used as markers of muscle damage. The dependent parameters were measured at baseline, immediately after and each day up to 96 hours after the exercise session. The intervention consisted of 100 repetitions of enhanced-eccentric squat exercise using flywheel device. The same protocol was repeated after 4 weeks.RESULTS: After the first bout, CK and muscle soreness were significantly greater (p0.05), while isometric peak torque and muscle soreness returned to values similar to baseline after respectively 48 and 72 hours. All muscle damage markers were significantly lower after second compared to first bout.CONCLUSION: The enhanced-eccentric exercise induced symptoms of muscle damage up to 96 hours. However, it provided muscle protection after the second bout, performed four weeks later. Although it was not eccentric-only exercise, the enhancement of eccentric phase provided muscle protection
Manipulating Resistance Exercise Variables to Improve Jumps, Sprints, and Changes of Direction in Soccer: What We Know and What We Don’t Know
Full text linkThe present review summarizes the effects of manipulating different resistance exercise variables on jumps, sprints, and changes of direction (CODs) in soccer. Regarding jumps, moderate-to-high loads, full range of movement (ROM), non-failure sets, and a moderate training volume are recommended. Different external resistances like constant-load, flywheel, or elastic bands, as well as various movement velocities and select exercises, are equally effective. As for sprints, moderate-to-high loads, constant load or flywheel but not elastic resistances, movements performed at full ROM, non-failure sets, and moderate-to-high training volume might be more effective, while numerous movement velocities and exercises could be chosen. As for CODs, moderate-to-high loads, flywheel more than constant-load resistance, and a moderate-to-high total number of repetitions are recommended, while several movement velocities and exercises could be selected, though ROM needs investigation. The effectiveness of concentric-only vs. eccentric-only training on jumps, sprints, and CODs has not been investigated, while an external focus and inter-set rest > 2 min are theoretically preferable, albeit not proven. Importantly, high movement velocity is not a prerogative of effectiveness, and limited ROM is not associated with sport-specific patterns such as jumps. Practitioners in soccer may manipulate resistance exercise variables depending on the purpose
Repeated bout effect induced by eccentric isoinertial device.
No full textMuscle damage is proved to occur after eccentric training (Clarkson, 2002). Moreover, it confers protection to a subsequent session, i.e.: repeated bout effect (Nosaka 2001). A new technology (YoYo technology) has been developed in order to enhance negative phase using inertia (Tesch 1994). Aim of the study is evaluate if lengthening contraction enhanced by inertial flywheel squat will cause symptoms of muscle injury and following protection.
Twelve healthy males performed 100 maximal squat repetitions using inertial device. At baseline, after training and up to 4 days after CK blood concentration, Knee extensors strength, muscle soreness and jump performance were measured as markers of muscle damage. Same protocol was repeated after 3 weeks. Statistical analysis was performed using repeated measures ANOVA, using factor Session and Day.
No significant Session X Day interaction occurred in all parameters. Single factor Session and Day were significant except in [CK]. Post hoc analysis revealed, compare to baseline and after first trainng, [CK] and soreness increments respectively up to 3 and 4 days, while strength loss and jump height were affected only post training. The second bout revealed significant markers decrements compared to the first one in CK (-50% and -43% after 2 and 3 days), muscle soreness (-2,8; -2,6; -3,4; -2,6 A.U. respectively after 1, 2 ,3 and 4 days) and strength ( 12%; 9%; 15%; 15%; 14% respectively immediately after training, after 1, 2, 3 and 4 days).
Inertial flywheel squat induce classical symptoms of muscle injury, even if strength loss and performance could be positively influenced by neural patterns. CK blood activity is relatively lower compared to single joint exercise because of load is divided among more muscles. However, eccentric overload does protect muscle at least up to 3 weeks. Trainers and conditioners should take in account the recovery time course after eccentric inertial squat.
Clarkson PM et al., Exercise Induced Muscle Damage in Humans. American journal of physical medicine & rehabilitation, 2002, 81(11)S: S52-69
Nosaka K et al., How long does the protective effect on eccentric exercise induced muscle damage last?. Medicine & Science in Sports & Exercise, 2001, 33(9): 1490-95
Tesch P et al., A gravity-independent ergometer to be used for resistance training in space. Aviation, space, and environmental medicine, 1994, 65(8): 752-
Active lifestyle promotion in COPD: preliminary data about recruitment and efficacy of different models of physical activity
No full textPhysical activity (PA) is considered as the most effective non-pharmacological intervention to alleviate symptoms and optimize functional capacity of patients with chronic obstructive pulmonary disease (COPD). However, a considerable proportion of eligible patients declines participation or drop out of PA programmes. The aim of the study is to determine the feasibility of recruiting patients with COPD and to access the efficacy of 3 months of different types of PA training models.269 males patients with COPD were identified from Respiratory Division of ULSS 20. Who match the study inclusion criteria (132) were contacted (92) to participate at our study. 37 partecipants were randomized in Fitness Center based activities (FC =13), in a PA Educational (EDU=12) and in a Control Group (CG=12). Behavioral, physiological and psychosocial outcome variables were reported pre and after 3 months of intervention. Analysis of covariance (ANCOVA) was performed to detect the significance of the change.Significant interactions were found in 6 minute walking test, upper and lower body strength, flexibility of the lower back, non dominant lower limb balance and IPAQ.
Post-hoc analysis revealed significant differences between CF and CG in 6 minute walking test performances (15.20% vs. -2.85%), upper body strength (19.13% vs. -2.35%) and non dominant lower limb balance (114.55% vs. 17.46); significant differences between EDU and CG were found in upper (15.25% vs. -2.35%) and lower (13.25% vs. -1.08%) body strength, flexibility (+5.92 cm vs. -0.55 cm) and IPAQ (68.13% vs. -31.66%). No differences were found between CF and EDU.
Compare to the literature, higher adherence (40% vs. 7%) to the program resulted in our study. Primary outcomes confirm the positive efficacy of physical activity programmes on physiologic parameters health related. EDU improvements was addicted to the high PA motivation provided by operators. Finally self-selected training can be used in order to improve the share of spontaneous PA and consequently health status, confirming ACSM international guidelines about PA support strategies
Eccentric resistance training increases and retains maximal strength, muscle endurance and hypertrophy in trained men
No full textThe aim of the present study was to evaluate the effects of different resistance training protocols on muscle strength, endurance, and hypertrophy after training and detraining. Thirty-four resistance-trained males were randomized in concentric-only (CONC), eccentric-only (ECC), traditional concentric-eccentric (TRAD) bench press resistance training or control group. The training volume was equalized among the intervention groups. Bench press of 1-repetition maximum (1RM)/body mass, maximum number of repetitions (MNR), and chest circumference were evaluated at the baseline, after 6 weeks of training, and after 6 weeks of detraining. All intervention groups reported significant 1RM/body mass increases after training (CONC baseline: 1.04 ± 0.06, post-training: 1.12 ± 0.08, p < 0.05; ECC baseline: 1.08 ± 0.04, post-training: 1.15 ± 0.05, p < 0.05; TRAD baseline: 1.06 ± 0.08, post-training: 1.11 ± 0.10, p < 0.05). After detraining, only ECC retained 1RM/body mass above the baseline (1.17 ± 0.07, p < 0.05), while CONC and TRAD returned to baseline values. Only ECC improved and retained MNR (baseline: 22 ± 3; post-training: 25 ± 3, and post-detraining: 25 ± 4, p < 0.05 compared with baseline) and chest circumference (baseline: 98.3 ± 2.4 cm, post-training: 101.7 ± 2.2 cm and post-detraining: 100.7 ± 2.3 cm. p < 0.05 compared with baseline), while no significant changes occurred in both CONC and TRAD. The incorporation of eccentric training can be recommended for counteracting the negative effects of detraining or forced physical inactivity
Effect of contraction modality on muscle strength and structure after resistance training and detraining
No full textIntroduction: Traditional resistance training involves both concentric and eccentric contraction, even if the latter has been shown to be more effective in total strength and muscle mass increment (Roig, 2009). However, often total training volume has been not considered. In addition, less is known about improvements retention after a detraining period. Therefore, aim of the study is to evaluate if muscle strength and structure changes are contraction dependent. In addition, we want to investigate if contraction modality can influence modifications retention after detraining.
Methods: Sixty healthy female sport science students were randomly allocated in eccentric only (E), concentric only (C), eccentric plus concentric training (E+C) or control group (CG). Training groups exercised isovolume unilateral isotonic leg extension for 8 weeks, while CG did not train. Isokinetic eccentric, concentric and isometric Maximal Voluntary Contraction (MVC), 1RM, vastus lateralis fascicle angle (FA), fascicle thickness (FT) and fascicle length(FL) and fat free mass (FFM) were recorded at baseline, 1 and 4 weeks after the end of training. Changes of dependent variables were detected using two- way repeated measures ANOVA.
Results: Significant two way interaction resulted in concentric (p<0,001), eccentric (p<0,001) and isometric (p<0.001) MVC, 1RM (p<0.001) and FA (p<0.05). FFM showed a strong tendency in two way interaction (p=0.058), while FT and FL did not displayed it. Post hoc analysis showed different strength coupling training-testing behavior both after training and detraining. FFM increased only in E after detraining (p<0.05). PA similarly increased in all training groups; FT incremented only in E (0.01) and C (0.05); Fascicle lengthened after detraining in E (p<0.01) and C (p<0.05).
Discussion: Effectiveness of resistance training depend both on volume and contraction modality. Confirming literature, high intensity resistance training showed muscle strength and improvement retention (Fatouros, 2005). Hence, even if high intensity isovolume resistance training improved total strength, contraction specific training- testing is a torque high lightening factor, with a superiority of eccentric training (Guilhem, 2012). Trainers and conditioners should keep in mind that a timeline adaptations knowledge resulted in a more effective training planning.
Fatouros, I. G., et al. (2005). Strength training and detraining effects on muscular strength, anaerobic power, and mobility of inactive older men are intensity dependent. British journal of sports medicine, 39(10)
Guilhem, G.,et al. (2012). Neuromuscular Adaptations to Isoload versus Isokinetic Eccentric Resistance Training. Medicine and science in sports and exercise.
Roig, M., et al.(2009). The effects of eccentric versus concentric resistance training on muscle strength and mass in healthy adults: a systematic review with meta-analysis. British journal of sports medicine, 43(8), 556–68
- …
