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1.
Einstein (Sao Paulo) ; 19: eAO5940, 2021.
Artigo em Inglês, Português | MEDLINE | ID: mdl-33886934

RESUMO

OBJECTIVE: To evaluate the effects of resistance training on metabolic and cardiovascular responses during maximal cardiopulmonary exercise testing in patients with Parkinson's disease. METHODS: Twenty-four patients with Parkinson's disease (modified Hoehn and Yahr stages 2 to 3) were randomly assigned to one of two groups: Control or Resistance Training. Patients in the Resistance Training Group completed an exercise program consisting of five resistance exercises (two to four sets of six to 12 repetitions maximum per set) twice a week. Patients in the Control Group maintained their usual lifestyle. Oxygen uptake, systolic blood pressure and heart rate were assessed at rest and during cycle ergometer-based maximal cardiopulmonary exercise testing at baseline and at 12 weeks. Assessments during exercise were conducted at absolute submaximal intensity (slope of the linear regression line between physiological variables and absolute workloads), at relative submaximal intensity (anaerobic threshold and respiratory compensation point) and at maximal intensity (maximal exercise). Muscle strength was also evaluated. RESULTS: Both groups had similar increase in peak oxygen uptake after 12 weeks of training. Heart rate and systolic blood pressure measured at absolute and relative submaximal intensities and at maximal exercise intensity did not change in any of the groups. Muscle strength increased in the Resistance Training but not in the Control Group after 12 weeks. CONCLUSION: Resistance training increases muscle strength but does not change metabolic and cardiovascular responses during maximal cardiopulmonary exercise testing in patients with Parkinson's disease without cardiovascular comorbidities.


Assuntos
Doença de Parkinson , Treinamento de Resistência , Limiar Anaeróbio , Teste de Esforço , Frequência Cardíaca , Humanos , Doença de Parkinson/terapia
2.
J Strength Cond Res ; 35(5): 1194-1200, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33900254

RESUMO

ABSTRACT: Teixeira, EL, Ugrinowitsch, C, de Salles Painelli, V, Silva-Batista, C, Aihara, AY, Cardoso, FN, Roschel, H, and Tricoli, V. Blood flow restriction does not promote additional effects on muscle adaptations when combined with high-load resistance training regardless of blood flow restriction protocol. J Strength Cond Res 35(5): 1194-1200, 2021-The aim of this study was to investigate, during high-load resistance training (HL-RT), the effect of blood flow restriction (BFR) applied during rest intervals (BFR-I) and muscle contractions (BFR-C) compared with HL-RT alone (no BFR), on maximum voluntary isometric contraction (MVIC), maximum dynamic strength (one repetition maximum [1RM]), quadriceps cross-sectional area (QCSA), blood lactate concentration ([La]), and root mean square of the surface electromyography (RMS-EMG) responses. Forty-nine healthy and untrained men (25 ± 6.2 years, 178.1 ± 5.3 cm and 78.8 ± 11.6 kg) trained twice per week, for 8 weeks. One leg of each subject performed HL-RT without BFR (HL-RT), whereas the contralateral leg was randomly allocated to 1 of 2 unilateral knee extension protocols: BFR-I or BFR-C (for all protocols, 3 × 8 repetitions, 70% 1RM). Maximum voluntary isometric contraction, 1RM, QCSA, and acute changes in [La] and RMS-EMG were assessed before and after training. The measurement of [La] and RMS-EMG was performed during the control sessions with the same relative load obtained after the 1RM test, before and after training. Similar increases in MVIC, 1RM, and QCSA were demonstrated among all conditions, with no significant difference between them. [La] increased for all protocols in pre-training and post-training, but it was higher for BFR-I compared with the remaining protocols. Increases in RMS-EMG occurred for all protocols in pre-training and post-training, with no significant difference between them. In conclusion, despite of a greater metabolic stress, BFR inclusion to HL-RT during rest intervals or muscle contraction did not promote any additive effect on muscle strength and hypertrophy.


Assuntos
Treinamento de Resistência , Humanos , Contração Isométrica , Masculino , Força Muscular , Músculo Esquelético , Músculo Quadríceps , Fluxo Sanguíneo Regional
3.
Med Sci Sports Exerc ; 2021 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-33731656

RESUMO

INTRODUCTION: Exercise-induced microRNAs (miRNAs) expression has been implicated in the regulation of skeletal muscle plasticity. However, the specificity and acute time course in miRNA expression following divergent exercise modes are unknown. In a randomized cross-over design, we compared the acute expression profile of eight skeletal muscle miRNAs previously reported to be involved in skeletal muscle development, growth and maintenance following a bout of either resistance exercise (RE), high intensity interval exercise (HIIE) and concurrent resistance and high intensity interval exercises (CE). METHODS: Nine untrained young men (23.9±2.8y, 70.1±14.9kg, 177.2±3.0cm, 41.4±5.2ml·kg-1·min-1) underwent a counter-balanced cross-over design in which they performed bouts of RE (2x10 repetitions maximum 45°Leg Press and Leg Extension exercises), HIEE (12x1 min sprints at VO2peak with 1min rest intervals between sprints) and CE (RE followed by HIIE), separated by one week. Vastus lateralis biopsies were harvested immediately before (Pre), and immediately (0h), 4h and 8h after each exercise bout. RESULTS: There were similar increases (main effect of time; P<0.05) in miR-1-3p,-133a-3p,-133b, -181a-3p, and -486 expression at 8h from Pre with all exercise modes. Besides a main effect of time, miR-23a-3p and -206 presented a main effect of condition with lower expression after HIIE compared to RE and CE. CONCLUSIONS: Select miRNAs (miR-1-3p, -133a-3p,-133b,-23a-3p,-181a-3p,-206,-486) do not exhibit an expression specificity in the acute recovery period following a single bout of either RE, HIIE or CE in skeletal muscle. Our data also indicate that RE has a higher effect on the expression of miR-23a-3p and -206 than HIIE. As upregulation of these miRNAs appears to be confined to the 8h period post-exercise, this may subsequently impact the expression patterns of target mRNAs forming the basis of exercise-induced adaptive responses.

4.
Gait Posture ; 85: 157-163, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33578308

RESUMO

BACKGROUND: Individuals with Parkinson's disease (PD) who report freezing of gait (FOG) have poorer sleep quality than those without FOG. Cognitive, anxiety, and mobility disability are components of the FOG phenotype, however, no study has investigated if poor sleep quality is associated with all three components that underlie FOG in PD. RESEARCH QUESTION: Are there associations among sleep quality and all three components of the FOG phenotype? METHODS: Forty and 39 individuals with and without FOG (PD + FOG and PD-FOG), respectively, and 31 age-matched healthy controls (HC) participated in this study. Self-reported FOG (new-FOG questionnaire-NFOGQ), sleep quality (Pittsburgh Sleep Quality Index-PSQI), cognitive function (Montreal Cognitive Assessment-MoCA), anxiety (subscale from Hospital Anxiety and Depression Scale-HADS-A), and mobility (timed-up-and-go test-TUG) were assessed. RESULTS AND SIGNIFICANCE: PSQI scores were correlated with the scores of NFOGQ, MoCA, HADS-A, and TUG time in PD + FOG (P ≤ 0.0038). The multiple regression analysis identified the PSQI scores as the only predictor of the variance of the NFOGQ scores (R2 = 0.46, P < .0001). The variance in the PSQI scores were explained (69 %) by MoCA scores, NFOGQ scores, TUG time, and HADS-A scores (P ≤ 0.05). Although PD + FOG had a higher disease severity compared to PD-FOG (P < 0.001), disease severity did not enter in the regression model to explain PSQI scores and NFOGQ scores. We also observed associations of PSQI scores with the MoCA scores and TUG time for HC (P ≤ 0.0038), whereas there was no association between PSQI scores and any variable in PD-FOG (P > 0.05). Finally, PD + FOG presented worse scores of PSQI, MoCA, HADS-A, and TUG time than PD-FOG and HC (P < 0.05). Thus, poor sleep quality is associated with FOG and all three components that underlie FOG, regardless of the disease severity. Therefore, treatments useful to decrease FOG should be targeted to ameliorate sleep quality, cognition, anxiety, and mobility.

5.
PLoS One ; 16(1): e0246014, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33481947

RESUMO

[This corrects the article DOI: 10.1371/journal.pone.0236592.].

7.
Sports Med ; 51(4): 599-605, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33405189

RESUMO

Previous research has suggested that concurrent training (CT) may attenuate resistance training (RT)-induced gains in muscle strength and mass, i.e.' the interference effect. In 2000, a seminal theoretical model indicated that the interference effect should occur when high-intensity interval training (HIIT) (repeated bouts at 95-100% of the aerobic power) and RT (multiple sets at ~ 10 repetition maximum;10 RM) were performed in the same training routine. However, there was a paucity of data regarding the likelihood of other HIIT-based CT protocols to induce the interference effect at the time. Thus, based on current HIIT-based CT literature and HIIT nomenclature and framework, the present manuscript updates the theoretical model of the interference phenomenon previously proposed. We suggest that very intense HIIT protocols [i.e., resisted sprint training (RST), and sprint interval training (SIT)] can greatly minimize the odds of occurring the interference effect on muscle strength and mass. Thus, very intensive HIIT protocols should be implemented when performing CT to avoid the interference effect. Long and short HIIT-based CT protocols may induce the interference effect on muscle strength when HIIT bout is performed before RT with no rest interval between them.

8.
J Gerontol A Biol Sci Med Sci ; 76(4): 568-575, 2021 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-33428714

RESUMO

Age-related changes in presynaptic inhibition (PSI) have not been observed during gait initiation, which requires anticipatory postural adjustment (APA). As APA is centrally modulated and is impaired in older compared to young adults, here we aimed to study the presynaptic control and co-contraction levels in the ankle muscles during gait initiation in older compared to young adults. Fifteen older (age range 65-80 years) and 15 young adults (age range 19-30 years) performed a gait initiation task on a force platform under 3 conditions: (i) without electrical stimulation; (ii) test Hoffman reflex (H-reflex); and (iii) conditioned H-reflex. H-reflexes were evoked on the soleus muscle when the APA amplitude exceeded 10%-20% of the average baseline mediolateral force. Participants also performed quiet stance as a control task. Results showed that both age groups presented similar PSI levels during quiet stance (p = .941), while in the gait initiation older adults presented higher PSI levels, longer duration, and lower amplitude of APA than young adults (p < .05). Older adults presented higher co-contraction ratio in both tasks than young adults (p < .05). Correlations between the PSI levels and the APA amplitude (r = -0.61, p = .008), and between the PSI levels and the co-contraction ratio during gait initiation (r = -0.64, p = .005) were found for older adults only. APA amplitude explained 49% of the variance of the PSI levels (p = .003). Our findings suggest that older compared to young adults have increased presynaptic control to compensate for the decreased supraspinal modulation on impaired APAs during gait initiation.

9.
Mov Disord ; 2020 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-32955752

RESUMO

BACKGROUND: Deficits in the cerebellar locomotor region (CLR) have been associated with loss of gait automaticity in individuals with freezing of gait in Parkinson's disease (freezers); however, exercise interventions that restore gait automaticity in freezers are lacking. We evaluated the effects of the adapted resistance training with instability ([ARTI] complex exercises) compared with traditional motor rehabilitation (without complex exercises) on gait automaticity and attentional set-shifting. We also verified associations between gait automaticity change and CLR activation change previously published. METHODS: Freezers were randomized either to the experimental group (ARTI, n = 17) or to the active control group (traditional motor rehabilitation, n = 15). Both training groups performed exercises 3 times a week for 12 weeks. Gait automaticity (dual-task and dual-task cost [DTC] on gait speed and stride length), single-task gait speed and stride length, attentional set-shifting (time between Trail Making Test parts B and A), and CLR activation during a functional magnetic resonance imaging protocol of simulated step initiation task were evaluated before and after interventions. RESULTS: Both training groups improved gait parameters in single task (P < 0.05), but ARTI was more effective than traditional motor rehabilitation in improving DTC on gait speed, DTC on stride length, dual-task stride length, and CLR activation (P < 0.05). Changes in CLR activation were associated with changes in DTC on stride length (r = 0.68, P = 0.002) following ARTI. Only ARTI improved attentional set-shifting at posttraining (P < 0.05). CONCLUSIONS: ARTI restores gait automaticity and improves attentional set-shifting in freezers attributed to the usage of exercises with high motor complexity. © 2020 International Parkinson and Movement Disorder Society.

10.
Artigo em Inglês | MEDLINE | ID: mdl-32887399

RESUMO

Previous research has demonstrated large amounts of inter-subject variability in downward (unweighting & braking) phase strategies in the countermovement jump (CMJ). The purpose of this study was to characterize downward phase strategies and associated temporal, kinematic and kinetic CMJ variables. One hundred and seventy-eight NBA (National Basketball Association) players (23.6 ± 3.7 years, 200.3 ± 8.0 cm; 99.4 ± 11.7 kg; CMJ height 68.7 ± 7.4 cm) performed three maximal CMJs. Force plate and 3D motion capture data were integrated to obtain kinematic and kinetic outputs. Afterwards, athletes were split into clusters based on downward phase characteristics (k-means cluster analysis). Lower limb joint angular displacement (i.e., delta flexion) explained the highest portion of point variability (89.3%), and three clusters were recommended (Ball Hall Index). Delta flexion was significantly different between clusters and players were characterized as "stiff flexors", "hyper flexors", or "hip flexors". There were no significant differences in jump height between clusters (p > 0.05). Multiple regression analyses indicated that most of the jumping height variance was explained by the same four variables, (i.e., sum concentric relative force, knee extension velocity, knee extension acceleration, and height) regardless of the cluster (p < 0.05). However, each cluster had its own unique set of secondary predictor variables.

11.
Cancers (Basel) ; 12(8)2020 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-32796499

RESUMO

While performing aerobic exercise during chemotherapy has been proven feasible and safe, the efficacy of aerobic training on cardiorespiratory fitness (CRF) in women with breast cancer undergoing chemotherapy has not yet been systematically assessed. Therefore, the objective of this work was to determine (a) the efficacy of aerobic training to improve CRF; (b) the role of aerobic training intensity (moderate or vigorous) on CRF response; (c) the effect of the aerobic training mode (continuous or interval) on changes in CRF in women with breast cancer (BC) receiving chemotherapy. A systematic review and meta-analysis were conducted as per PRISMA guidelines, and randomized controlled trials comparing usual care (UC) and aerobic training in women with BC undergoing chemotherapy were eligible. The results suggest that increases in CRF are favored by (a) aerobic training when compared to usual care; (b) vigorous-intensity aerobic exercise (64-90% of maximal oxygen uptake, VO2max) when compared to moderate-intensity aerobic exercise (46-63% of VO2max); and (c) both continuous and interval aerobic training are effective at increasing the VO2max. Aerobic training improves CRF in women with BC undergoing chemotherapy. Notably, training intensity significantly impacts the VO2max response. Where appropriate, vigorous intensity aerobic training should be considered for women with BC receiving chemotherapy.

12.
PLoS One ; 15(8): e0236592, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32790792

RESUMO

Caffeine improves cycling time trial performance through enhanced motor output and muscle recruitment. However, it is unknown if caffeine further increases power output entropy. To investigate the effects of caffeine effects on cycling time trial performance and motor output entropy (MOEn), nine cyclists (VO2MAX of 55 ± 6.1 mL.kg.-1min-1) performed a 4 km cycling time trial (TT4km) after caffeine and placebo ingestion in a counterbalanced order. Power output data were sampled at a 2 Hz frequency, thereafter entropy was estimated on a sliding-window fashion to generate a power output time series. A number of mixed models compared performance and motor output entropy between caffeine and placebo every 25% of the total TT4km distance. Caffeine ingestion improved power output by 8% (p = 0.003) and increased MOEn by 7% (p = 0.018). Cyclists adopted a U-shaped pacing strategy after caffeine ingestion. MOEn mirrored power output responses as an inverted U-shape MOEn during the time trial. Accordingly, a strong inverse correlation was observed between MOEn and power output responses over the last 25% of the TT4km (p < 0.001), regardless of the ingestion, likely reflecting the end spurt during this period (p = 0.016). Caffeine ingestion improved TT4km performance and motor output responses likely due to a greater power output entropy.


Assuntos
Desempenho Atlético , Cafeína/farmacologia , Estimulantes do Sistema Nervoso Central/farmacologia , Resistência Física/efeitos dos fármacos , Adulto , Ciclismo , Entropia , Humanos , Masculino , Efeito Placebo
13.
Mov Disord ; 35(9): 1607-1617, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32557868

RESUMO

BACKGROUND: Exercises with motor complexity induce neuroplasticity in individuals with Parkinson's disease (PD), but its effects on freezing of gait are unknown. The objective of this study was to verify if adapted resistance training with instability - exercises with motor complexity will be more effective than traditional motor rehabilitation - exercises without motor complexity in improving freezing-of-gait severity, outcomes linked to freezing of gait, and brain function. METHODS: Freezers were randomized either to the adapted resistance training with instability group (n = 17) or to the active control group (traditional motor rehabilitation, n = 15). Both training groups performed exercises 3 times a week for 12 weeks. The primary outcome was the New Freezing of Gait Questionnaire. Secondary outcomes were freezing of gait ratio (turning task), cognitive inhibition (Stroop-III test), motor signs (Unified Parkinson's Disease Rating Scale part-III [UPDRS-III]), quality of life (PD Questionnaire 39), anticipatory postural adjustment (leg-lifting task) and brain activation during a functional magnetic resonance imaging protocol of simulated anticipatory postural adjustment task. Outcomes were evaluated before and after interventions. RESULTS: Only adapted resistance training with instability improved all the outcomes (P < 0.05). Adapted resistance training with instability was more effective than traditional motor rehabilitation (in improving freezing-of-gait ratio, motor signs, quality of life, anticipatory postural adjustment amplitude, and brain activation; P < 0.05). Our results are clinically relevant because improvement in the New Freezing of Gait Questionnaire (-4.4 points) and UPDRS-III (-7.4 points) scores exceeded the minimally detectable change (traditional motor rehabilitation group data) and the moderate clinically important difference suggested for PD, respectively. The changes in mesencephalic locomotor region activation and in anticipatory postural adjustment amplitude explained the changes in New Freezing of Gait Questionnaire scores and in freezing-of-gait ratio following adapted resistance training with instability, respectively. CONCLUSIONS: Adapted resistance training with instability is able to cause significant clinical improvement and brain plasticity in freezers. © 2020 International Parkinson and Movement Disorder Society.

14.
J Strength Cond Res ; 2020 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-32304519

RESUMO

Gomes, RL, Lixandrão, ME, Ugrinowitsch, C, Moreira, A, Tricoli, V, and Roschel, H. Session rating of perceived exertion as an efficient tool for individualized resistance training progression. J Strength Cond Res XX(X): 000-000, 2020-The present study aimed to investigate the effects of an individualized resistance training (RT) progression model based on the session rating of perceived exertion (RPE) on gains in muscle mass and strength when compared with a conventional predetermined progression method (PP). Twenty previously trained young male subjects were randomly allocated to 1 of the 2 groups: RPE (n = 10) or PP (n = 10). Muscle cross-sectional area (CSA) and maximum dynamic strength were assessed at baseline and after 6 weeks. The RPE-based progression model resulted in a lower number of high-intensity sessions compared with the PP-based model. Despite this, both groups showed significant and similar increases in CSA (p < 0.0001; RPE = 6.55 ± 5.27% and PP = 9.65 ± 3.63%) and strength (p < 0.0001; RPE = 9.68 ± 4.57% and PP = 9.28 ± 4.01%) after the intervention period. No significant between-group difference was observed for total training volume (RPE = 45,366.00 ± 10,190.00 kg and PP = 47,779.00 ± 5,685.00 kg; p = 0.52). Our results showed that an RT progression model based on session-to-session physiological response assessments resulted in fewer high-intensity training sessions while allowing for similar gains in muscle strength and mass. Thus, trainees are encouraged to adopt session RPE as a potential tool to control workload progression throughout a training period and allowing the optimization of training stimulus on an individual basis.

15.
J Physiol ; 598(8): 1611-1624, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32020612

RESUMO

KEY POINTS: Individuals with freezing of gait (FoG) due to Parkinson's disease (PD) have small and long anticipatory postural adjustments (APAs) associated with delayed step initiation. Individuals with FoG ('freezers') may require functional reorganization of spinal mechanisms to perform APAs due to supraspinal dysfunction. As presynaptic inhibition (PSI) is centrally modulated to allow execution of supraspinal motor commands, it may be deficient in freezers during APAs. We show that freezers presented PSI in quiet stance (control task), but they presented loss of PSI (i.e. higher ratio of the conditioned H-reflex relative to the test H-reflex) during APAs before step initiation (functional task), whereas non-freezers and healthy control individuals presented PSI in both the tasks. The loss of PSI in freezers was associated with both small APA amplitudes and FoG severity. We hypothesize that loss of PSI during APAs for step initiation in freezers may be due to FoG. ABSTRACT: Freezing of gait (FoG) in Parkinson's disease involves deficient anticipatory postural adjustments (APAs), resulting in a cessation of step initiation due to supraspinal dysfunction. Individuals with FoG ('freezers') may require functional reorganization of spinal mechanisms to perform APAs. As presynaptic inhibition (PSI) is centrally modulated to allow execution of supraspinal motor commands, here we hypothesized a loss of PSI in freezers during APA for step initiation, which would be associated with FoG severity. Seventy individuals [27 freezers, 22 non-freezers, and 21 age-matched healthy controls (HC)] performed a 'GO'-commanded step initiation task on a force platform under three conditions: (1) without electrical stimulation, (2) test Hoffman reflex (H-reflex) and (3) conditioned H-reflex. They also performed a control task (quiet stance). In the step initiation task, the H-reflexes were evoked on the soleus muscle when the amplitude of the APA exceeded 10-20% of the mean baseline mediolateral force. PSI was quantified by the ratio of the conditioned H-reflex relative to the test H-reflex in both the tasks. Objective assessment of FoG severity (FoG-ratio) was performed. Freezers presented lower PSI levels during quiet stance than non-freezers and HC (P < 0.05). During step initiation, freezers presented loss of PSI and lower APA amplitudes than non-freezers and HC (P < 0.05). Significant correlations were only found for freezers between loss of PSI and FoG-ratio (r = 0.59, P = 0.0005) and loss of PSI and APA amplitude (r = -0.35, P < 0.036). Our findings suggest that loss of PSI for step initiation in freezers may be due to FoG.

16.
J Strength Cond Res ; 2020 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-32058362

RESUMO

Aube, D, Wadhi, T, Rauch, J, Anand, A, Barakat, C, Pearson, J, Bradshaw, J, Zazzo, S, Ugrinowitsch, C, and De Souza, EO. Progressive resistance training volume: effects on muscle thickness, mass, and strength adaptations in resistance-trained individuals. J Strength Cond Res XX(X): 000-000, 2020-This study investigated the effects of 12-SET, 18-SET, and 24-SET lower-body weekly sets on muscle strength and mass accretion. Thirty-five resistance-trained individuals (one repetition maximum [1RM] squat: body mass ratio [1RM: BM] = 2.09) were randomly divided into 12-SET: n = 13, 18-SET: n = 12, and 24-SET: n = 10. Subjects underwent an 8-week resistance-training (RT) program consisting of 2 weekly sessions. Muscle strength (1RM), repetitions to failure (RTF) at 70% of 1RM, anterior thigh muscle thickness (MT), at the medial MT (MMT) and distal MT (DMT) points, as well as the sum of both sites (ΣMT), along with region of interest for fat-free mass (ROI-FFM) were measured at baseline and post-testing. For the 1RM, there was a main time effect (p ≤ 0.0001). However, there was a strong trend toward significance (p = 0.052) for group-by-time interaction, suggesting that 18-SET increased 1RM back squat to a greater extent compared with 24-SET, (24-SET: 9.5 kg, 5.4%; 18-SET: 25.5 kg, 16.2%; 12-SET: 18.3 kg, 11.3%). For RTF, only a main time-effect (p ≤ 0.0003) was observed (24-set: 5.7 reps, 33.1%; 18-SET: 2.4 reps, 14.5%; 12-SET: 5.0 reps, 34.8%). For the MMT, DMT, ΣMT, and ROI-FFM, there was only main time-effect (p ≤ 0.0001), (MMT: 24-SET: 0.15 cm, 2.7%; 18-SET: 0.32 cm, 5.7%; 12-SET: 0.38 cm, 6.4%-DMT: 24-set: 0.39 cm, 13.1%; 18-SET: 0.28 cm, 8.9%; 12-SET: 0.34 cm, 9.7%-ΣMT: 24-set: 0.54 cm, 6.1%; 18-SET: 0.60 cm, 6.7%; 12-SET: 0.72 cm, 7.7%, and ROI-FFM: 24-set: 0.70 kg, 2.6%; 18-SET: 1.09 kg, 4.2%; 12-SET: 1.20 kg, 4.6%, respectively). Although all of the groups increased maximum strength, our results suggest that the middle dose range may optimize the gains in back squat 1RM. Our findings also support that differences in weekly set number did not impact in MT and ROI-FFM adaptations in subjects who can squat more than twice their body mass.

17.
J Strength Cond Res ; 2020 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-32108724

RESUMO

Scarpelli, MC, Nóbrega, SR, Santanielo, N, Alvarez, IF, Otoboni, GB, Ugrinowitsch, C, and Libardi, CA. Muscle hypertrophy response is affected by previous resistance training volume in trained individuals. J Strength Cond Res XX(X): 000-000, 2020-The purpose of this study was to compare gains in muscle mass of trained individuals after a resistance training (RT) protocol with standardized (i.e., nonindividualized) volume (N-IND), with an RT protocol using individualized volume (IND). In a within-subject approach, 16 subjects had one leg randomly assigned to N-IND (22 sets·wk, based on the number of weekly sets prescribed in studies) and IND (1.2 × sets·wk recorded in training logs) protocols. Muscle cross-sectional area (CSA) was assessed by ultrasound imaging at baseline (Pre) and after 8 weeks (Post) of RT, and the significance level was set at p < 0.05. Changes in the vastus lateralis CSA (difference from Pre to Post) were significantly higher for the IND protocol (p = 0.042; mean difference: 1.08 cm; confidence interval [CI]: 0.04-2.11). The inferential analysis was confirmed by the CI of the effect size (0.75; CI: 0.03-1.47). Also, the IND protocol had a higher proportion of individuals with greater muscle hypertrophy than the typical error of the measurement (chi-square, p = 0.0035; estimated difference = 0.5, CI: 0.212-0.787). In conclusion, individualizing the weekly training volume of research protocols provides greater gains in muscle CSA than prescribing a group standard RT volume.

18.
J Strength Cond Res ; 34(4): 1133-1140, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29016481

RESUMO

Rauch, JT, Ugrinowitsch, C, Barakat, CI, Alvarez, MR, Brummert, DL, Aube, DW, Barsuhn, AS, Hayes, D, Tricoli, V, and De Souza, EO. Auto-regulated exercise selection training regimen produces small increases in lean body mass and maximal strength adaptations in highly trained individuals. J Strength Cond Res 34(4): 1133-1140, 2020-The purpose of this investigation was to compare the effects of auto-regulatory exercise selection (AES) vs. fixed exercise selection (FES) on muscular adaptations in strength-trained individuals. Seventeen men (mean ± SD; age = 24 ± 5.45 years; height = 180.3 ± 7.54 cm, lean body mass [LBM] = 66.44 ± 6.59 kg; squat and bench press 1 repetition maximum (1RM): body mass ratio 1.87, 1.38, respectively) were randomly assigned into either AES or FES. Both groups trained 3 times a week for 9 weeks. Auto-regulatory exercise selection self-selected the exercises for each session, whereas FES was required to perform exercises in a fixed order. Lean body mass was assessed via dual-energy X-ray absorptiometry and maximum strength via 1RM testing, pre-, and post-training intervention. Total volume load was significantly higher for AES than for FES (AES: 573,288 ± 67,505 kg; FES: 464,600 ± 95,595 kg, p = 0.0240). For LBM, there was a significant main time effect (p = 0.009). However, confidence interval analysis (95% CIdiff) suggested that only AES significantly increased LBM (AES: 2.47%, effect size [ES]: 0.35, 95% CIdiff [0.030-3.197 kg]; FES: 1.37%, ES: 0.21, 95% CIdiff [-0.500 to 2.475 kg]). There was a significant main time effect for maximum strength (p ≤ 0.0001). However, 95% CIdiff suggested that only AES significantly improved bench press 1RM (AES: 6.48%, ES: 0.50, 95% CIdiff [0.312-11.42 kg]; FES: 5.14%, ES: 0.43, 95% CIdiff [-0.311 to 11.42 kg]). However for back squat 1RM, similar responses were observed between groups (AES: 9.55%, ES: 0.76, 95% CIdiff [0.04-28.37 kg]; FES: 11.54%, ES: 0.80, 95% CIdiff [1.8-28.5 kg]). Our findings suggest that AES may provide a small advantage in LBM and upper body maximal strength in strength-trained individuals.


Assuntos
Composição Corporal/fisiologia , Força Muscular/fisiologia , Músculo Esquelético/fisiologia , Treinamento de Resistência/métodos , Absorciometria de Fóton , Adaptação Fisiológica , Adulto , Humanos , Masculino , Postura , Adulto Jovem
19.
PM R ; 12(3): 281-287, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31278834

RESUMO

BACKGROUND: Minimal detectable change (MDC) when assessing balance using the Biodex Balance System (BBS) in patients with Parkinson disease (PD) is currently unknown, limiting the interpretability of the scores. OBJECTIVE: To determine the MDC on the Anterior/Posterior Stability Index (APSI), Medial/Lateral Stability Index (MLSI), and Overall Stability Index (OSI) from postural stability and fall risk protocols of the BBS in patients with PD. DESIGN: This was a repeated-measures design (at a 1-week interval). SETTING: Strength training laboratory of a public university. PATIENTS: 46 patients with PD (men and women) at stages 2 and 3 (67.9 ± 7.4 years old) were assessed in the "on" state (fully medicated). METHODS: Patients performed three trials of 20 s for each protocol. MAIN OUTCOME MEASUREMENTS: Absolute and relative MDC (MDC%) calculated for APSI, MLSI, and OSI from the postural stability (stable condition) and fall risk protocols (unstable condition). RESULTS: For the postural stability, the MDC and MDC% were 0.26° and 17% for APSI, 0.41° and 21% for MLSI, and 0.22° and 12% for OSI, respectively. For the fall risk, the MDC and MDC% were 0.51° and 18% for APSI, 0.21° and 15% for MLSI, and 0.41° and 20% for OSI, respectively. These results were considered acceptable, despite indices with high MDC for MLSI (postural stability) and APSI (fall risk). CONCLUSIONS: Patients with PD have more mediolateral and anteroposterior changes in the stable and unstable conditions, respectively. These abnormal balance strategies can occur principally due to postural instability of PD. However, our results demonstrated acceptable MDCs in both conditions in all of the assessed axes. Thus, BBS should be incorporated into the clinical evaluation to help therapists to determine if intervention-induced changes in balance are clinically significant or due to measurement error. LEVEL OF EVIDENCE: II.

20.
Med Sci Sports Exerc ; 52(2): 507-514, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31469710

RESUMO

PURPOSE: Sleep is considered essential for muscle recovery, mainly due to its effect on hormone secretion. Total sleep deprivation or restriction is known to alter not only blood hormones but also cytokines that might be related to skeletal muscle recovery. This study aimed to evaluate whether total sleep deprivation after eccentric exercise-induced muscle damage (EEIMD) modifies the profiles of blood hormones and cytokines. METHODS: In two separate conditions, with a crossover and randomized model, 10 men (age, 24.5 ± 2.9 yr; body mass index, 22.7 ± 2.3 kg·m) performed a unilateral EEIMD protocol that comprised 240 eccentric contractions of the knee extensor muscles using an isokinetic dynamometer. In one condition, a "muscle damage" protocol was followed by 48 h of total sleep deprivation and 12 h of normal sleep (DEPRIVATION). In the other condition, the same muscle damage protocol was conducted, followed by three nights of regular sleep (SLEEP). Isometric muscle voluntary contraction tests and blood samples were collected serially throughout the protocol and analyzed for creatine kinase, free and total testosterone, IGF-1, cortisol, tumor necrosis factor-alpha, interleukin (IL)-1beta, IL-6, receptor antagonist of IL-1 and IL-10. RESULTS: Muscle voluntary contraction and serum creatine kinase increased equally over the study period in both conditions. From the cytokines evaluated, only IL-6 increased in DEPRIVATION. No differences were detected in testosterone levels between conditions, but IGF-1, cortisol, and cortisol/total testosterone ratio were higher in DEPRIVATION. CONCLUSIONS: Total sleep deprivation after EEIMD does not delay muscle strength recovery but modifies inflammatory and hormonal responses.


Assuntos
Exercício Físico/fisiologia , Músculo Esquelético/fisiologia , Privação do Sono/fisiopatologia , Adulto , Creatina Quinase/sangue , Estudos Cross-Over , Humanos , Hidrocortisona/sangue , Joelho/fisiologia , Masculino , Contração Muscular/fisiologia , Força Muscular/fisiologia , Receptores de Interleucina-6/sangue , Testosterona/sangue , Fator de Necrose Tumoral alfa/sangue , Adulto Jovem
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