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1.
Int J Sports Med ; 45(5): 369-376, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38346688

RESUMO

This study aimed to investigate the impact of bar velocity during the eccentric phase on subsequent concentric performance in the young and elderly. Twelve elderly women (65.2+4.2 years) and 16 young women (23.1+2.1 years) were randomly assigned to four experimental conditions that combined high-velocity eccentric actions (HVECC; maximum velocity) and moderate-velocity eccentric actions (MVECC; 2.0 s), using 30% and 60% of their 1-repetition maximum (1RM) on the Smith machine bench press. Measurements of mean propulsive velocity (MPV), peak velocity (PV), and mean power (MP) were recorded. Two-way ANOVA with repeated measures was applied for each variable, when needed, the Bonferroni post hoc was used. Statistical significance was set at p<0.05, and effect size (ES) was established by Cohen's d z. The results demonstrated that elderly women showed improved performance in MPV (+10.0%; ES=- 0.58; p=0.009) and MP (+11.7%; ES=- 0.14; p=0.045) when utilizing HVECC at 30% 1RM only. Moreover, young women exhibited superior performance for both 30% and 60% 1RM when using HVECC for all variables analyzed (p<0.05). The HVECC appears to have an impact on the subsequent performance of the concentric phase, particularly when lighter loads (30% 1RM) are utilized, regardless of the age group.


Assuntos
Força Muscular , Levantamento de Peso , Humanos , Feminino , Idoso , Levantamento de Peso/fisiologia , Adulto Jovem , Força Muscular/fisiologia , Fatores Etários , Treinamento Resistido/métodos , Pessoa de Meia-Idade , Adulto , Músculo Esquelético/fisiologia , Desempenho Atlético/fisiologia
2.
Int J Sports Med ; 42(4): 371-376, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32252103

RESUMO

The study compared the effects of resistance training programs composed by multi-joint (MJ), single-joint (SJ) and the combination of multi- and single-joint (MJ+SJ) exercises on muscle strength and hypertrophy in trained women. Thirty participants were divided into groups that performed only MJ exercises, SJ exercises and MJ+SJ exercises for six months. Participants were tested for 1-repetition maximum (RM) and muscle thickness (MT) before and after the intervention. All groups showed significant gains on 1RM tests from pre- to post-training (P<0.01). However, MJ and MJ+SJ groups obtained greater gains in 1RM for the MJ exercises in comparison with the SJ group. Increases in 1RM for the SJ exercises were similar among groups, with the exception of leg curl, where the SJ group obtained greater gains than MJ and MJ+SJ. All groups obtained significant increases in MT from pre- to post-training for all muscle groups. However, MJ and MJ+SJ groups presented greater increases in gluteus maximus, quadriceps femoris and pectoralis major in comparison with the SJ group. Therefore, our results suggest that, in general, performing MJ exercises seems to be necessary to obtain optimal results from a resistance training program; however SJ might be necessary to provide optimal strength gains in knee flexion.


Assuntos
Força Muscular/fisiologia , Músculo Esquelético/anatomia & histologia , Treinamento Resistido/métodos , Adulto , Feminino , Humanos , Articulações/fisiologia , Tamanho do Órgão , Músculos Peitorais/anatomia & histologia , Músculo Quadríceps/anatomia & histologia , Fatores de Tempo
3.
J Transl Med ; 18(1): 88, 2020 02 17.
Artigo em Inglês | MEDLINE | ID: mdl-32066460

RESUMO

BACKGROUND: The present study compared the effects of training and detraining periods of high-intensity interval training (HIIT), moderate-intensity interval training (MIIT) and moderate-intensity continuous training (MICT) on functional performance, body composition, resting blood pressure and heart rate in elderly women nursing home residents. METHODS: Forty-six volunteers (age, 80.8 ± 5.2 y; body mass, 69.8 ± 5.2 kg, height, 164.2 ± 4.12 cm) were divided into groups that performed treadmill exercise twice-weekly HIIT (4 bouts of 4-min intervals at 85-95% of the maximal heart rate [HRmax], interspersed by 4 min at 65% HRmax), MIIT (4 bouts of 4 min intervals at 55-75% HRmax, interspersed by 4 min at 45-50% HRmax) and MICT (30-min at 55-75% HRmax). Tests were performed before and after 8 weeks of training and 2 and 4 weeks of detraining. ANCOVA was used to analyze dependent variable changes. RESULTS: After 8 weeks HIIT promoted greater reductions in body mass (HIIT = - 1.6 ± 0.1 kg; MICT = - 0.9 ± 0.1 kg; MIIT = - 0.9 ± 0.1 kg; p = 0.001), fat mass (HIIT = - 2.2 ± 0.1%; MICT = - 0.7 ± 0.1%; MIIT = - 1.2 ± 0.1%; p < 0.001) and resting heart rate (HIIT = - 7.3 ± 0.3%; MICT = - 3.6 ± 0.3%; MIIT = - 5.1 ± 0.3%; p < 0.001) and greater improvement in the chair stand test (HIIT = 3.4 ± 0.1 reps; MICT = 2.5 ± 0.1 reps; MIIT = 3.1 ± 0.1 reps; p < 0.001) when compared to MIIT and MICT. These improvements were sustained after 2 and 4 weeks of detraining only in the HIIT group. CONCLUSION: HIIT promoted greater benefits for body composition and functional performance than MICT and MIIT and also showed less pronounced effects of detraining. This suggests that the intensity of physical exercise is an important factor to consider when prescribing exercise to the elderly.


Assuntos
Treinamento Intervalado de Alta Intensidade , Idoso , Idoso de 80 Anos ou mais , Pressão Sanguínea , Exercício Físico , Teste de Esforço , Feminino , Frequência Cardíaca , Humanos
4.
Int J Sports Med ; 41(5): 306-310, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31975359

RESUMO

The study compared the effects of back squat (BS) and hip thrust (HT) exercises on muscle strength and hypertrophy in well-trained women. Twenty-two participants were divided in two groups: BS group (n=12, 26.4±1.32 years, 171.8±3.79 cm, and 69.5±4.9 kg) performed the BS exercise and HT group (n=10, 27.5±1.42 years, 170.8±4.4 cm, 67.5±4.7 kg) performed the HT exercise. Training was performed for 12 weeks. Before and after the training period, participants were assessed for quadriceps femoris and gluteus maximus muscle thickness (MT) and 1 repetition maximum (1RM) test on the BS and HT. Both groups significantly increased hip extensors MT and HT 1RM; however, the improvements in BS group were higher than in HT group on quadriceps femoris (12.2% for BS and 2% for HT, P<0.001) and gluteus maximus MT (9.4% for BS and 3.7% for HT, P=0.001) and BS 1 RM (35.9% for BS and 4.3% for HT, P<0.001). BS was more efficient than HT, since it resulted in greater muscle hypertrophy of the quadriceps femoris and gluteus maximus, increases in BS 1RM and similar increases in HT.


Assuntos
Força Muscular/fisiologia , Músculo Esquelético/anatomia & histologia , Músculo Esquelético/fisiologia , Treinamento Resistido/métodos , Levantamento de Peso/fisiologia , Adulto , Feminino , Humanos , Músculo Quadríceps/anatomia & histologia , Músculo Quadríceps/fisiologia
5.
J Strength Cond Res ; 34(8): 2214-2219, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29781936

RESUMO

Barbalho, M, Gentil, P, Raiol, R, Fisher, J, Steele, J, and Coswig, V. Influence of adding single-joint exercise to a multijoint resistance training program in untrained young women. J Strength Cond Res 34(8): 2214-2219, 2020-The aim of the present study was to investigate the effects of adding single-joint (SJ) exercises to a multijoint (MJ) resistance training (RT) program on muscle strength and anthropometric measures of young women. Twenty untrained women were divided into a group that performed only MJ exercises or a group that performed both SJ and MJ exercises (MJ + SJ). Before and after 8 weeks of training, the participants were tested for 10 repetition maximum (10RM). Flexed arm circumference and triceps and biceps skinfold thickness were also measured. Both groups significantly decreased biceps (-3.60% for MJ and -3.55% for MJ + SJ) and triceps skinfold (-3.05% for MJ and -2.98% for MJ + SJ), with no significant difference between them. Flexed arm circumference significantly increased in both groups; however, increases in MJ + SJ (4.39%) were significantly greater than MJ (3.50%). Increases in 10RM load in elbow extension (28.2% for MJ and 28.0% for MJ + SJ), elbow flexion (29.8% for MJ and 28.7% for MJ + SJ), and knee extension (26.92% for MJ and 23.86% for MJ + SJ) were all significant and not different between groups. The results showed that adding SJ exercises to an MJ RT program resulted in no additional benefits in muscle performance, whilst differences in flexed arm circumference were small, but significant, in untrained women.


Assuntos
Força Muscular/fisiologia , Músculo Esquelético/fisiologia , Treinamento Resistido/métodos , Pesos e Medidas Corporais , Articulação do Cotovelo/fisiologia , Feminino , Humanos , Articulação do Joelho/fisiologia , Extremidade Inferior/fisiologia , Masculino , Extremidade Superior/fisiologia , Adulto Jovem
6.
Clin Rehabil ; 33(2): 233-240, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30246555

RESUMO

OBJECTIVE:: To evaluate the addition of blood flow restriction to passive mobilization in patients in the intensive care unit. DESIGN:: The study was a within-patient randomized trial. SETTING:: Two intensive care units in Belém, from September to October 2017. SUBJECTS:: In total, 34 coma patients admitted to the intensive care unit sector, and 20 patients fulfilled the study requirements. INTERVENTIONS:: All participants received the passive mobilization protocol for lower limbs, and blood flow restriction was added only for one side in a concurrent fashion. Intervention lasted the entire patient's hospitalization time. MAIN OUTCOME MEASUREMENT:: Thigh muscle thickness and circumference. RESULTS:: In total, 34 subjects were enrolled in the study: 11 were excluded for exclusion criteria, 3 for death, and 20 completed the intervention (17 men and 3 women; mean age: 66 ± 4.3 years). Despite both groups presented atrophy, the atrophy rate was lower in blood flow restriction limb in relation to the control limb (-2.1 vs. -2.8 mm, respectively, in muscle thickness; P = 0.001). In addition, the blood flow restriction limb also had a smaller reduction in the thigh circumference than the control limb (-2.5 vs. -3.6 cm, respectively; P = 0.001). CONCLUSION:: The use of blood flow restriction did not present adverse effects and seems to be a valid strategy to reduce the magnitude of the rate of muscle wasting that occurs in intensive care unit patients.


Assuntos
Extremidade Inferior/irrigação sanguínea , Terapia Passiva Contínua de Movimento/métodos , Sarcopenia/prevenção & controle , Idoso , Cuidados Críticos , Feminino , Hospitalização , Humanos , Unidades de Terapia Intensiva , Extremidade Inferior/fisiopatologia , Masculino , Pessoa de Meia-Idade
7.
Br J Sports Med ; 53(10): 655-664, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30765340

RESUMO

OBJECTIVES: To compare the effects of interval training and moderate-intensity continuous training (MOD) on body adiposity in humans, and to perform subgroup analyses that consider the type and duration of interval training in different groups. DESIGN: Systematic review and meta-analysis. DATA SOURCES: English-language, Spanish-language and Portuguese-language searches of the electronic databases PubMed and Scopus were conducted from inception to 11 December 2017. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Studies that met the following criteria were included: (1) original articles, (2) human trials, (3) minimum exercise training duration of 4 weeks, and (4) directly or indirectly compared interval training with MOD as the primary or secondary aim. RESULTS: Of the 786 studies found, 41 and 36 were included in the qualitative analysis and meta-analysis, respectively. Within-group analyses showed significant reductions in total body fat percentage (%) (interval training: -1.50 [95% CI -2.14 to -0.86, p<0.00001] and MOD: -1.44 [95% CI -2.00 to -0.89, p<0.00001]) and in total absolute fat mass (kg) (interval training: -1.58 [95% CI -2.74 to -0.43, p=0.007] and MOD: -1.13 [95% CI -2.18 to -0.08, p=0.04]), with no significant differences between interval training and MOD for total body fat percentage reduction (-0.23 [95% CI -1.43 to 0.97], p=0.705). However, there was a significant difference between the groups in total absolute fat mass (kg) reduction (-2.28 [95% CI -4.00 to -0.56], p=0.0094). Subgroup analyses comparing sprint interval training (SIT) with MOD protocols favour SIT for loss of total absolute fat mass (kg) (-3.22 [95% CI -5.71 to -0.73], p=0.01). Supervised training, walking/running/jogging, age (<30 years), study quality and intervention duration (<12 weeks) favourably influence the decreases in total absolute fat mass (kg) observed from interval training programmes; however, no significant effect was found on total body fat percentage (%). No effect of sex or body mass index was observed on total absolute fat mass (kg) or total body fat percentage (%). CONCLUSION: Interval training and MOD both reduce body fat percentage (%). Interval training provided 28.5% greater reductions in total absolute fat mass (kg) than MOD. TRIAL REGISTRATION NUMBER: CRD42018089427.


Assuntos
Treinamento Intervalado de Alta Intensidade , Redução de Peso , Adiposidade , Exercício Físico , Humanos
8.
Int J Sport Nutr Exerc Metab ; 29(1): 1-8, 2019 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-29757051

RESUMO

We aimed to describe the nutritional and behavioral strategies for rapid weight loss (RWL), investigate the effects of RWL and weight regain in winners and losers, and verify mood state and technical-tactical/time-motion parameters in mixed martial arts. The sample consisted of mixed martial arts athletes after a single real match and was separated into two groups: winners (n = 8; age: 25.4 ± 6.1 years, height: 173.9 ± 0.2 cm, habitual body mass: 89.9 ± 17.3 kg) and losers (n = 7; age: 24.4 ± 6.8 years, height: 178.4 ± 0.9 cm, habitual body mass: 90.8 ± 19.5 kg). Both groups exhibited RWL and weight regain, verified their macronutrient intake, underwent weight and height assessments, and completed two questionnaires (Profile of Mood States and RWL) at (a) 24 hr before weigh-in, (b) weigh-in, (c) postbout, and (d) during a validated time-motion and technical-tactical analysis during the bout. Variance analysis, repeated measures, and a logistic regression analysis were used. The main results showed significant differences between the time points in terms of total caloric intake as well as carbohydrate, protein, and lipid ingestion. Statistical differences in combat analysis were observed between the winners and losers in terms of high-intensity relative time (58 [10-98] s and 32 [1-60] s, respectively), lower limb sequences (3.5 [1.0-7.5] sequences and 1.0 [0.0-1.0] sequences, respectively), and ground and pound actions (2.5 [0.0-4.5] actions and 0.0 [0.0-0.5] actions, respectively), and logistic regression confirmed the importance of high-intensity relative time and lower limb sequences on mixed martial arts performance. RWL and weight regain strategies were related to technical-tactical and time-motion patterns as well as match outcomes. Weight management should be carefully supervised by specialized professionals to reduce health risks and raise competitive performance.

10.
J Strength Cond Res ; 30(8): 2156-63, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26817739

RESUMO

Coswig, VS, Ramos, SdP, and Del Vecchio, FB. Time-motion and biological responses in simulated mixed martial arts sparring matches. J Strength Cond Res 30(8): 2156-2163, 2016-Simulated matches are a relevant component of training for mixed martial arts (MMA) athletes. This study aimed to characterize time-motion responses and investigate physiological stress and neuromuscular changes related to MMA sparring matches. Thirteen athletes with an average age of 25 ± 5 years, body mass of 81.3 ± 9.5 kg, height of 176.2 ± 5.5 cm, and time of practice in MMA of 39 ± 25 months participated in the study. The fighters executed three 5-minute rounds with 1-minute intervals. Blood and salivary samples were collected and physical tests and psychometric questionnaires administered at 3 time points: before (PRE), immediately after (POST), and 48 hours after the combat (48 h). Statistical analysis applied analysis of variance for repeated measurements. In biochemical analysis, significant changes (p ≤ 0.05) were identified between PRE and POST (glucose: 80.3 ± 12.7 to 156.5 ± 19.1 mg·ml; lactate: 4 ± 1.7 to 15.6 ± 4.8 mmol·dl), POST and 48 hours (glucose: 156.5 ± 19.1 to 87.6 ± 15.5 mg·ml; lactate: 15.6 ± 4.8 to 2.9 ± 3.5 mmol·dl; urea: 44.1 ± 8.9 to 36.3 ± 7.8 mg·ml), and PRE and 48 hours (creatine kinase [CK]: 255.8 ± 137.4 to 395.9 ± 188.7 U/L). In addition, time-motion analyses showed a total high:low intensity of 1:2 and an effort:pause ratio of 1:3. In conclusion, simulated MMA sparring matches feature moderate to high intensity and a low degree of musculoskeletal damage, which can be seen by absence of physical performance and decrease in CK. Results of the study indicate that sparring training could be introduced into competitive microcycles to improve technical and tactical aspects of MMA matches, due to the high motor specificity and low muscle damage.


Assuntos
Artes Marciais/fisiologia , Adulto , Desempenho Atlético/fisiologia , Biomarcadores/metabolismo , Creatina Quinase/metabolismo , Glucose/metabolismo , Humanos , Ácido Láctico/metabolismo , Masculino , Estresse Fisiológico/fisiologia , Estudos de Tempo e Movimento
11.
Int J Sport Nutr Exerc Metab ; 25(5): 480-6, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25811230

RESUMO

The purpose of this study was to compare biochemical and hormonal responses between mixed martial arts (MMA) competitors with minimal prefight weight loss and those undergoing rapid weight loss (RWL). Blood samples were taken from 17 MMA athletes (Mean± SD; age: 27.4 ±5.3yr; body mass: 76.2 ± 12.4kg; height: 1.71 ± 0.05m and training experience: 39.4 ± 25 months) before and after each match, according to the official events rules. The no rapid weight loss (NWL, n = 12) group weighed in on the day of the event (~30 min prior fight) and athletes declared not having used RWL strategies, while the RWL group (n = 5) weighed in 24 hr before the event and the athletes claimed to have lost 7.4 ± 1.1kg, approximately 10% of their body mass in the week preceding the event. Results showed significant (p < .05) increases following fights, regardless of group, in lactate, glucose, lactate dehydrogenase (LDH), creatinine, and cortisol for all athletes. With regard to group differences, NWL had significantly (p < .05) greater creatinine levels (Mean± SD; pre to post) (NWL= 101.6 ± 15-142.3 ± 22.9µmol/L and RWL= 68.9 ± 10.6-79.5 ± 15.9µmol/L), while RWL had higher LDH (median [interquartile range]; pre to post) (NWL= 211.5[183-236] to 231[203-258]U/L and RWL= 390[370.5-443.5] to 488[463.5-540.5]U/L) and AST (NWL= 30[22-37] to 32[22-41]U/L and 39[32.5-76.5] to 72[38.5-112.5] U/L) values (NWL versus RWL, p < .05). Post hoc analysis showed that AST significantly increased in only the RWL group, while creatinine increased in only the NWL group. The practice of rapid weight loss showed a negative impact on energy availability and increased both muscle damage markers and catabolic expression in MMA fighters.


Assuntos
Artes Marciais/fisiologia , Fenômenos Fisiológicos da Nutrição Esportiva/fisiologia , Redução de Peso/fisiologia , Adulto , Aspartato Aminotransferases/sangue , Glicemia/análise , Creatinina/sangue , Humanos , Hidrocortisona/sangue , Lactato Desidrogenases/sangue , Ácido Láctico/sangue , Masculino
12.
J Strength Cond Res ; 29(12): 3399-404, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26595133

RESUMO

The deadlift is a fundamental exercise used in the development of whole body strength and a common element in resistance training programs for all levels. However, many practitioners report the fatigue of forearm muscles and possibly a lack of grip strength as obstacles to exercise performance, which may lead to the use of ergogenic aids, such as lifting straps. The objective of this study was to evaluate kinematic variables during the execution of multiple sets of deadlift with (WS) and without (NS) lifting straps. Eleven subjects (25 ± 3.3 years) with an average of 4 ± 2.6 years of resistance training experience were enrolled in the study. After the 1 repetition maximum (1RM) test WS and NS, subjects performed separate trials of 3 sets to failure at 90% of 1RM in a counterbalanced fashion. With straps resulted in lower speed (0 to -25%) (-3 to -10%) and greater force (20-28%) and duration (concentric phase: 0-13%) when compared with NS. Therefore, it is concluded that the use of straps directly influences exercise performance that requires manual grip strength, increasing the amount of work performed by the target muscles.


Assuntos
Treinamento Resistido/instrumentação , Treinamento Resistido/métodos , Adulto , Fenômenos Biomecânicos/fisiologia , Estudos Cross-Over , Humanos , Cinética , Masculino , Força Muscular/fisiologia , Distribuição Aleatória
13.
Sports Med Health Sci ; 6(2): 111-122, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38708326

RESUMO

There is a recent and growing interest in assessing differential responders to resistance training (RT) for diverse outcomes. Thus, the individual ability to respond to an intervention for a specific measurement, called responsiveness, remains to be better understood. Thus, the current study aimed to summarize the available information about the effects of RT on functional performance and muscle strength, power, and size in healthy adults, through the prevalence rate in different responsiveness classifications models. A systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and was registered at the International Prospective Register of Systematic Reviews (PROSPERO, CRD42021265378). PubMed/MEDLINE, Scopus, and Embase databases were systematically searched in October 2023. A total of 13 studies were included, totaling 921 subjects. Only two studies presented a low risk of bias. Regarding the effectiveness of RT, the prevalence rate for non-responders ranged from 0% to 44% for muscle strength, from 0% to 84% for muscle size, and from 0% to 42% for functional performance, while for muscle power, the only study found showed a responsiveness rate of 37%. In conclusion, a wide range of differential responders is described for all variables investigated. However, the evidence summarized in this systematic review suggested some caution while interpreting the findings, since the body of evidence found seems to be incipient, and widely heterogeneous in methodological and statistical aspects.

14.
PeerJ ; 12: e17387, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38770095

RESUMO

Purpose: The aim of this study was to assess the reliability and validity of the My Jump 2® app in measuring jump height, flight time, and peak power among elite women beach volleyball players on sand surfaces. Methods: Eleven elite female beach volleyball players (aged 23.6 ± 6.2 years; weight 66.3 ± 5.8 kg; height 174.4 ± 5.8 cm; with 8.4 ± 4.8 years of professional experience) participated in this study. Each player performed six countermovement jumps in a wooden box filled with sand on a force platform while simultaneously recording a video for subsequent analysis using the My Jump 2® app. Results: We found excellent agreement for flight time, jump height and peak power between observers (ICC = 0.92, 0.91 and 0.97, respectively). No significant differences between force platform and My Jump 2® app were detected in the values obtained for the three variables (P > 0.05). For the force platform and the My Jump 2® app, we found a good agreement measuring jump height and flight time (ICC = 0.85 and 0.85, respectively). However, we only found a moderate agreement for peak power (ICC = 0.64). The difference in jump height showed a limit of agreement between -4.10 and 4.74 cm in Bland-Altman, indicating a high level of agreement between the two measurement tools. Conclusion: Based on our findings, the My Jump 2® app reveals a valid tool for measuring jump height and flight time of CMJ on sand surfaces. However, more caution is needed when measuring peak power.


Assuntos
Aplicativos Móveis , Voleibol , Humanos , Feminino , Voleibol/fisiologia , Reprodutibilidade dos Testes , Adulto Jovem , Adulto , Desempenho Atlético/fisiologia , Teste de Esforço/métodos , Teste de Esforço/instrumentação , Atletas
15.
PeerJ ; 11: e14764, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36743962

RESUMO

In combat sports, strikes or counter-strikes response time (RT) can be related to performance and sporting success. Moreover, training sessions are usually highly fatiguing, which is expected to impair basic skills, such as RT. Thus, this study aimed to investigate the effect of fatigue on punch and kick RTs of karate practitioners. Twelve individuals of both sexes from different levels (three yellow belts, three red belts, two orange belts, two green belts, one brown belt, and one black belt) were selected. Participants were aged 22 ± 3 years old, with a stature of 169.1 ± 6.5 cm, and a body mass of 65.5 ± 10 kg. Six visits were held with each participant. On the first 2 days, the RT of punches and kicks was measured by a validated smartphone app (TReaction). For the subsequent visits, a randomized incremental test for the upper or lower body was adopted as motor fatigue protocol, immediately followed by punches and kicks RT tests, also in random order. For induction of lower and upper body-specific muscle fatigue, the ITStriker app was used, which operates by emitting sound signals transmitted by a smartphone. One-way repeated measures ANOVA was performed, and significance was set at p ≤ 0.05. Regarding the mean punches RT, significant effects between situations for the upper (F(2,22) = 11.5; ω2 = 0.23; p < 0.001) and lower body (F(2,22) = 14.2; ω2 = 0.18; p < 0.001) fatigue protocols were found. The negative effect of the lower body fatigue protocol in punches RT was evident regardless of the order of the tests (punch RT first: Δ = 10.5%; t = 4.4; p < 0.001; d = 1.0; kick RT first: Δ = 11.4%; t = 4.8; p < 0.001; d = 1.1). Regarding mean kicks RT, significant effects were found between situations for the lower (F(2,22) = 16.6; ω2 = 0.27; p < 0.001) but not for the upper (F(2,22) = 2.3; ω2 = 0.02; p = 0.12) body fatigue protocols. Kick RTs were negatively affected by the lower body fatigue protocol regardless of the RT order applied (punch RT first: Δ = 7.5%; t = 3.0; p = 0.01; d = 0.8; kick RT first: Δ = 14.3%; t = 5.7; p < 0.001; d = 1.5). Upper body fatigue does not impair punch or kick RTs. Thus, it is concluded that the specificity of fatigue protocols and striking order should be considered while performing RT demanding techniques in karate practice. Specifically, lower body motor fatigue may impair both kicks and punches RT, which highlights the role of lower limbs in punches performance. Otherwise, upper body motor fatigue seems to induce impairments that are limited to the specific motor actions of this body segment.


Assuntos
Artes Marciais , Adulto , Feminino , Humanos , Masculino , Adulto Jovem , Atletas , Extremidade Inferior/fisiologia , Artes Marciais/fisiologia , Fadiga Muscular , Tempo de Reação
17.
PeerJ ; 10: e13654, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36039367

RESUMO

Background: Taekwondo is an intermittent Olympic combat sport, which shows an aerobic predominance in matches and high participation of alactic metabolism for actions that determine competitive success. However, there is no information on energetic contribution systems in different high-intensity intermittent exercises for metabolic conditioning with specific movements. The study aimed to measure the physiological demands, mainly the energy expenditure, in taekwondo-specific high-intensity intermittent exercises (HIIE). Methods: This study recruited ten male black belt athletes with a mean age of 20.2 ± 4 years, body mass of 62.8 ± 10.5 kg and height of 170.6 ± 7.8 cm, and total practice time of 11.8 ± 5.4 years. Subjects performed an incremental specific test and three different HIIE protocols on nonconsecutive days, and all comprised three 2-min rounds and 1 min of recovery between rounds. Heart rate, oxygen consumption, and blood lactate were measured. Energetic expenditure of aerobic, alactic, and lactic metabolisms was estimated through oxygen consumption, excess post-exercise oxygen consumption, and peak blood lactate after each round. Results: For the mean of the three rounds, the TKDtest100 resulted in higher absolute and relative contribution from the aerobic metabolism (52.4 ± 4%; p = 0.01) and lower than the 35:5 relative alactic contribution (48.7 ± 5.4%; p = 0.03). Conclusion: The mean of the three rounds for 35:5 and 15:10:5 presented similar absolute and relative contributions of aerobic and alactic metabolisms, whereas the TKDtest100 was a predominantly aerobic activity. We emphasize that aerobic metabolism was predominant from the second round in the 15:10:5 and 100%TKDtest protocols and in the last round of the 35:5 protocol.


Assuntos
Treinamento Intervalado de Alta Intensidade , Artes Marciais , Humanos , Masculino , Adolescente , Adulto Jovem , Adulto , Ácido Láctico , Artes Marciais/fisiologia , Metabolismo Energético/fisiologia , Exercício Físico/fisiologia
18.
Int J Exerc Sci ; 15(4): 771-782, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35992500

RESUMO

This study aimed to compare the effects of high-speed resistance training (HSRT) and low-speed resistance training (LSRT) in physical fitness, and functional performance in untrained older women. Twenty-four women (62.2 ± 2.7 years old) were allocated to the HSRT or LSRT groups. The HSRT and LSRT groups underwent a similar training program [3 sets of 8 to 12 repetitions at 90% of 10 maximum repetitions] for 14 weeks, twice a week. The LSRT group performed the exercises with 3 seconds in the concentric and eccentric phases, while the HSRT group performed with the concentric phase as quickly as possible and 3 seconds in the eccentric phase. Participants completed pre-and post-training testing to assess strength, flexibility, muscle endurance, power, walking speed, functional balance, and aerobic endurance. Two-way mixed-model ANOVA with repeated measures was applied for each variable, and the Bonferroni post hoc was used when necessary. Statistical significance was set at p < 0.05. No significant group*time interactions were found for any variable. Time main-effect suggested significant improvements for the 10 RM bench press (F = 46.1; p < 0.001), 10 RM leg press (F = 49.8; p < 0.001), sit-to-stand test (F = 10.4; p = 0.004), sit and reach (F = 10.5; p = 0.004), Timed Up-and-Go (F = 29.8; p < 0.001) and 6-min walking test (F = 41.6; p < 0.001). Thus, the configurations of RT tested here were similarly efficient to improve the functional performance of untrained older women. In addition, both groups showed significant gains in muscle strength, but not in muscle power and gait speed.

19.
Front Physiol ; 12: 637590, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33746777

RESUMO

The novel coronavirus disease (COVID-19) has emerged at the end of 2019 and caused a global pandemic. The disease predominantly affects the respiratory system; however, there is evidence that it is a multisystem disease that also impacts the cardiovascular system. Although the long-term consequences of COVID-19 are not well-known, evidence from similar diseases alerts for the possibility of long-term impaired physical function and reduced quality of life, especially in those requiring critical care. Therefore, rehabilitation strategies are needed to improve outcomes in COVID-19 survivors. Among the possible strategies, resistance training (RT) might be particularly interesting, since it has been shown to increase functional capacity both in acute and chronic respiratory conditions and in cardiac patients. The present article aims to propose evidence-based and practical suggestions for RT prescription for people who have been diagnosed with COVID-19 with a special focus on immune, respiratory, and cardiovascular systems. Based on the current literature, we present RT as a possible safe and feasible activity that can be time-efficient and easy to be implemented in different settings.

20.
Front Psychol ; 12: 656499, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34290647

RESUMO

Background: Mental fatigue is a psychobiological state caused by extended periods of cognitive effort, and evidence suggests that mentally fatigued athletes present impaired physical performance. Different ergogenic aids have been proposed to counteract the deleterious effects of mental fatigue, but whether brain stimulation can counteract mental fatigue is still unknown. This scenario is even more obscure considering the effects of these interventions (mental fatigue induction and brain stimulation) in a very experienced population consisting of master athletes. Method: Ten master swimmers (30 ± 6 years old and 14 ± 8 years of experience) participated in the study. They underwent four experimental conditions before an 800-m freestyle test: mental fatigue with brain stimulation; mental fatigue without brain stimulation; absence of mental fatigue with brain stimulation; and absence of mental fatigue and no brain stimulation. Mental fatigue was induced by a cognitively demanding Stroop Color Test, whereas stimulation was applied on the temporal cortex. After that, the athletes swan 800 m as fast as possible and provided their ratings of perceived exertion (RPE) every 200 m. Results: Mental fatigue was effectively induced, as evidenced by a greater fatigue perception and more errors in the last blocks of the cognitive task. Mental fatigue induction did not influence performance (time to complete the swimming trial) and RPE. Similarly, brain stimulation failed to change these two parameters, regardless of mental fatigue induction. Conclusion: The prolonged physical performance of experienced master athletes is not influenced, under the present conditions, by mental fatigue induction, cerebral stimulation, and their association.

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