Strength training improves heart function, collagen and strength in rats with heart failure.

BACKGROUND/OBJECTIVES: Myocardial infarction (MI) frequently leads to cardiac remodeling and failure with impaired life quality, playing an important role in cardiovascular deaths. Although physical exercise is a well-recognized effective non-pharmacological therapy for cardiovascular diseases, the effects of strength training (ST) on the structural and functional aspects of cardiac remodeling need to be further documented. In this study, we aimed to investigate the role of a linear block ST protocol in the rat model of MI. METHODS AND RESULTS: After 6 weeks of MI induction or sham surgery, male adult rats performed ST for the following 12 weeks. The ladder-based ST program was organized in three mesocycles of 4 weeks, with one load increment for each block according to the maximal carrying load test. After 12 weeks, the infarcted-trained rats exhibited an increase in performance, associated with reduced cardiac hypertrophy and pulmonary congestion compared with the untrained group. Despite not changing MI size, the ST program partially prevented cardiac dilatation and ventricular dysfunction assessed by echocardiography and hemodynamics, and interstitial fibrosis evaluated by histology. In addition, isolated cardiac muscles from infarcted-trained rats had improved contractility parameters in a steady state, and in response to calcium or stimuli pauses. CONCLUSIONS: The ST in infarcted rats increased the capacity to carry mass, associated with attenuation of cardiac remodeling and pulmonary congestion with improving cardiac function that could be attributed, at least in part, to the improvement of myocardial contractility.

Effect of Supervised and Unsupervised Exercise Training in Outdoor Gym on the Lifestyle of Elderly People.

The aim of this study was to investigate the effectiveness of supervised and unsupervised physical training programs using outdoor gym equipment on the lifestyles of elderly people. METHODS: physically independent elderly people were randomly distributed into three groups: supervised training (n: 20; ST), unsupervised training (n: 20; UT) and control (n: 20; C). The ST and UT groups completed a 12-week program, with exercises performed three times a week. The ST group underwent weekly 30 min sessions consisting of a 5 min warm-up (walking at 60% of HRmax), followed by 20 sets of 30, "monitored by a metronome with 30" of passive recovery between sets and a five-minute cool-down. The following equipment was used: elliptical, rowing, surfing and leg press. The UT group was instructed to freely attend the gym and train spontaneously using the same equipment used by ST. Lifestyle changes were evaluated using a questionnaire containing specific domains. RESULTS: no significant differences were identified in the domains for family, physical activity, nutrition, smoking, sleep, behavior, introspection, work and overall score; however, the values corresponding to the alcohol domain for the ST and UT groups were lower (p < 0.05) than the C group, remaining even lower after the 12 weeks of intervention. Time effect (p < 0.05) was found only in the ST group for the physical domains, sleep, behavior and overall score. CONCLUSION: elderly people submitted to supervised and unsupervised physical exercise programs using outdoor gym equipment present positive changes in lifestyle parameters compared to physical inactive elderly people.

Skeletal Muscle Discomfort and Lifestyle of Brazilian Military Police Officers of Administrative and Tactical Force.

Our aim was to evaluate musculoskeletal discomfort and the lifestyle of military police officers of administrative and tactical force departments. Military police officers were distributed into two groups: administrative (Adm, n = 15) and tactical force (TF, n = 16) departments. Their lifestyle was assessed using the Fantastic Lifestyle questionnaire. Moreover, physical activity quantification was assessed using the International Physical Activity questionnaire, and musculoskeletal discomfort was quantified using the Corlett diagram. The mean total time of physical activity was 546 ± 276 min per week. No differences (p = 0.0832) were found between the Adm (454 ± 217 min) and TF (623 ± 301 min) groups. Concerning lifestyle, in general the sample presented very good (42%) and good (42%) style classification. For this parameter, no significant differences were found, but only a tendency was discovered (x2: 7.437; p = 0.0592); indeed, the TF presented a better classification (63%) of very good, compared to the Adm (53%) of good. No differences (p > 0.05) were found in musculoskeletal perception of discomfort between the right and left sides (p > 0.05) for all police officers and between the Adm and FT groups (p > 0.05). Military police officers showed high and moderate risk for waist circumference and waist-to-hip ratio, respectively; however, lifestyle and total time of physical activity were considered adequate without differences between military administrative and tactical force sectors.

Exercise-Induced Muscle Damage after a High-Intensity Interval Exercise Session: Systematic Review.

High-intensity interval training (HIIT) is considered an effective method to improve fitness and health indicators, but its high-intensity exercises and the mechanical and metabolic stress generated during the session can lead to the occurrence of exercise-induced muscle damage. Therefore, this study aimed to describe, by means of a systematic review, the effects of a single HIIT session on exercise-induced muscle damage. A total of 43 studies were found in the Medline/PubMed Science Direct/Embase/Scielo/CINAHL/LILACS databases; however, after applying the exclusion criteria, only 15 articles were considered eligible for this review. The total sample was 315 participants. Among them, 77.2% were men, 13.3% were women and 9.5 uninformed. Their age ranged from 20.1 ± 2 to 47.8 ± 7.5 years. HIIT protocols included running with ergometers (n = 6), CrossFit-specific exercises (n = 2), running without ergometers (n = 3), swimming (n = 1), the Wingate test on stationary bicycles (n = 2), and cycling (n = 1). The most applied intensity controls were %vVO2max, "all out", MV, MAV, Vmax, and HRreserve%. The most used markers to evaluate muscle damage were creatine kinase, myoglobin, and lactate dehydrogenase. The time for muscle damage assessment ranged from immediately post exercise to seven days. HIIT protocols were able to promote changes in markers of exercise-induced muscle damage, evidenced by increases in CK, Mb, LDH, AST, ALT, pain, and muscle circumference observed mainly immediately and 24 h after the HIIT session.

Effect of Sodium Bicarbonate Supplementation on Muscle Performance and Muscle Damage: A Double Blind, Randomized Crossover Study.

Sodium bicarbonate (NaHCO3) has been used as an ergogenic substance during high-intensity exercises. Therefore, the aim of the present study was to investigate the effects of NaHCO3 supplementation on external and internal load parameters during isokinetic exercise in trained subjects. Ten subjects were tested on two occasions: after ingesting 0.3 g.kg-1 of body mass of NaHCO3 or placebo. Maximum voluntary isometric contraction was performed before and after a dynamic protocol consisting of 10 series of 10 movements of flexion/extension of the knee extensors at 120° s-1 at an interval of 60 s between series. Outcomes considered were: peak torque (isokinetic dynamometry), blood lactate and creatine concentration (CK), analysis of perceptions of effort (OMNI scale), pain (visual analog scale) and recovery (scale raging 6 to 20). Performance was assessed using peak torque values. Muscle damage was assessed prior and 24 h post exercise. The subjective perceptions of effort, pain and recovery were assessed at different times and the internal load of the session was assessed 30 min post-effort. Although significant reductions in peak torque were noted both in isometric (NaHCO3:-29.11 ± 22.95%, Placebo: -23.51 ± 15.23%; p = 0.38) and isokinetic strength (NaHCO3:-23.0 ± 13.9%, Placebo:-19.6 ± 9.1%; p = 0.09), there was no effect of supplementation on performance (p > 0.05). The blood CK concentrations (NaHCO3: pre:225.3 ± 135.9 U/L, post: 418.4 ± 318.4 U/L; Placebo: pre:238 ± 94.03 U/L, post:486 ± 336.6 U/L) increased after protocol (p = 0.005), however, without differences between conditions. In conclusion, the NaHCO3 did not attribute benefits in performance or in parameters related to the internal load of exercise.

Psychophysiological Responses of Exercise Distribution During High Intensity Interval Training Using Whole Body Exercise.

The time-efficient nature of HIIT using bodyweight exercises can facilitate the application of exercise programs at home by encouraging more people to perform regular physical exercise. However, there are no studies investigating the influence of the distribution/order of exercises during HIIT training sessions using this method. The aim of the present study was to evaluate the effects of different exercise orders on training load indicators during HIIT sessions using body weight. Twenty male participants performed three 20-min sessions of HIIT using whole body exercise, consisting of 20 sets with 30 s of activity performed at maximal intensity, followed by 30 s of passive recovery. Three designs of exercise protocols were randomly performed according to the following exercise distribution: A: jumping jack, burpee, mountain climb and squat jump); B: jumping jack, mountain climb, burpee, and squat jump) and C: burpee, squat jump, jumping jack and mountain climb. No differences were found between protocols for relative heart rate, perceived exertion, and lactate concentrations. Significant differences (p < 0.001) were found for the number of movements (A:712 ± 59, B:524 ± 49, C:452 ± 65). No differences were observed for the area under curve when examining perceived exertion between protocols. However, the values for perceived recovery significantly differed (p < 0.001) between protocols (A:64 ± 19; B:52 ± 11; C:17 ± 13). Interestingly, protocol B and C induced a displeasure perception compared to protocol A. Our findings suggest that exercise distribution/order using HIIT whole body exercise promotes alterations in psychophysiological responses in HIIT using whole body exercises.

Effects of music on psychophysiological responses during high intensity interval training using body weight exercises.

The use of music in exercise sessions is considered an interesting strategy as it facilitates, through motivation, an improvement in physical performance, as well as a reduction in the subjective perception of effort and an improvement in mood. Such factors are important for the maintenance of physical exercise programs, however, considering high intensity interval training, the effects of music remain inconclusive. Thus, the objective of this study was to evaluate the influence of music during high intensity interval training sessions using body weight (HIIT-B) on the physiological parameters and mood state of adults. METHODS: 11 CrossFit male practitioners were randomly submitted to three sessions of HIIT-B under the following experimental conditions: preference music (PM), non-preference music (nPM) and without music (WM). The HIIT-B protocol consisted of 20 sets of 30 s of stimulus using maximal intensities followed by 30 s of passive recovery. The following exercises were used: jumping jacks, burpee, mountain climber and squat jumping. The following parameters were analyzed: heart rate (HR), lactate (La), total amount of movements (TAM), affective response (AR), rating of perceived exertion (RPE), recovery (RPR) and mood states. RESULTS: although an increase (p< 0.05) of HR, RPE and La, reduction of RPR was found after performing the HIIT session, no differences were found between the three conditions to these parameters. The nPM condition promoted lower (p< 0.001) TAM compared to the WM and PM conditions, which also differed from each other. However, for AR, a music effect was found among the protocols (p< 0.0001), indicating that the PM session promoted an increase in pleasure, unlike WM and nPM session which provided pleasure reduction and displeasure respectively. The WM session did not promote any changes. There were no main effects on time for depression and anger, which were different for vigor, fatigue, mental confusion, tension and mood disturbance. Additionally, differences were found after session to tension (p = 0.0229), vigor (p = 0.0424) and fatigue (p = 0.0400) for PM condition, vigor (p = 0.0424), fatigue (p = 0.0400) mental confusion (p = 0.0302) and mood disturbance (p = 0.0129) for nPM and vigor (p = 0.0363) and fatigue (p = 0.0468) to WM conditions. CONCLUSION: Listening to preferred music during an 'all out' HIIT-B session increases exercise performance and elicits more positive affective responses in recreationally active adult males, despite similar HR, blood lactate, RPE and fatigue compared to nonpreferred music or no-music.

Effect of a short-term whole-body high-intensity interval training on fitness, morphological, and functional parameters in untrained individuals.

BACKGROUND: High-intensity interval training protocols using the body weight (WB-HIIT) as resistance could be an interesting and inexpensive alternative due to the absence of equipment required (low cost) and the possibility to be performed in a wide range of locations. Therefore, the purpose of the present study was to analyze the effects of a short-term WB-HIIT protocol on muscle thickness (MT), muscular endurance (ME), one maximum repetition test (1RM), and maximum oxygen uptake (VO2max) of untrained individuals. METHODS: Fifty healthy men (28.2±6.7 years, 77.5±26.2 kg, 171±10 cm, 23.2±8.2% Fat) were randomized into WB-HIIT (N.=25) or control (CON, N.=25) group. The WB-HIIT performed 9 exercises (40-second stimulus in all out intensity/ 20-second of passive recovery) divided into 3 blocks with 2 sets each for 6 weeks (three times a week). RESULTS: Only WB-HIIT resulted in a significant increase in MT, ME, 1RM, and VO2max (all P<0.05) outcomes and were significantly greater compared to CON (all P<0.05). CONCLUSIONS: Our results demonstrate that a WB-HIIT program can be a time-efficient strategy to promote changes on fitness, morphological and functional parameters in previously untrained sedentary individuals.

Physical exercise attenuates stress-induced hypertension in rats but not the impairments on the myocardial mechanics.

BACKGROUND: Acute and chronic stresses have become a health problem in the contemporary society, and prolonged exposure to stressful events are related to the pathogenesis of cardiovascular diseases. Physical exercise is a well-recognized effective nonpharmacological therapy for cardiovascular diseases and stress-induced injuries. Thus, this study evaluated the effect of exercise on the cardiac remodelling of chronically stressed rats. METHODS AND RESULTS: Wistar adult rats were used (n = 10 each group) and chronic stress protocol consisted of restricting movement in individual rodent restrainers (60 min, 5 days/week, 12 weeks); and exercise consisted of swimming sessions in a pool (60 min, 5 days/week, 12 weeks). During protocol, blood pressure was measured in conscious rats, and at the end cardiac morphology/function was assessed. Animals exposed to stress exhibited continuous rise in blood pressure from the sixth week, but exercise attenuated it. Similarly, restrained rats increased serum corticosterone compared with nonstressed rats, but exercise also prevented it. No changes were found in cardiac mass, but chronic stress not only impaired the steady state contractions of the cardiac muscle, but also reduced inotropic responses to stretching, increasing calcium and beta-adrenergic receptor stimulation. Despite this, exercise was unable to prevent these functional impairments induced by stress, and instead, the association of stress and physical exercise worsened myocardial compliance. CONCLUSION: Despite the known benefits to the cardiovascular system, our results indicate that aerobic swimming exercise for 12 weeks reduced blood pressure but did not impede the chronic stress-induced myocardial damages in rats.

The dose-response phenomenon associated with strength training is independent of the volume of sets and repetitions per session / O fenômeno de dose-resposta associado ao treinamento de força é independente do volume de séries e repetições por sessão / El fenómeno de dosis-respuesta asociado al entrenamiento de fuerza es independiente del volumen de series y repeticiones por sesión

ABSTRACT Introduction There are few studies on the effectiveness of training models with high volume sets per session in particular muscle groups. Objective The aim of the study was to investigate the effects of different resistance training (RT) repetitions with equalized volumes on muscle adaptations. Methods This study used an experimental design in which forty-seven volunteers underwent 8 weeks of RT after having been distributed randomly into three groups: ten sets of three maximum repetitions (10x3), three sets of ten maximum repetitions (3x10) and five sets of six maximum repetitions (5x6) for each muscular group per training session. Maximum strength (1RM test) and muscle thickness (MT) were evaluated as outcomes. Results A significant main effect (p=0.001) of time on maximum strength was observed for the three groups, but no significance was observed (p>0.05) in time x group interactions. A significant main effect (p=0.001) of time was observed on MT for biceps, triceps and vastus lateralis, without significant differences for time x group interactions. Significant correlations were found between maximum strength and muscle thickness after general statistical analyses for all protocols. Conclusion Improvements in maximum strength and muscle thickness are similar when repetition volumes are equalized through the number of series and repetitions. Level of evidence I; Therapeutic studies, investigation of treatment results.

RESUMO Introdução Existem poucos estudos sobre a eficácia de modelos de treinamento com conjuntos de alto volume por sessão em grupos musculares específicos. Objetivos O objetivo do estudo foi investigar os efeitos de diferentes repetições do treinamento de resistência (TR) com volumes equalizados nas adaptações musculares. Métodos Este estudo tem desenho experimental com 47 voluntários que realizaram oito semanas de TR depois de serem distribuídos randomicamente em três grupos: dez séries de três repetições máximas (10x3), três séries de dez repetições máximas (3x10) e cinco séries de seis repetições máximas (5x6) para cada grupo muscular por sessão de treinamento. A força máxima (teste de 1RM) e a espessura muscular (EM) foram avaliadas como desfecho. Resultados Verificou-se efeito significativo (p = 0,001) sobre o tempo na força máxima nos três grupos, contudo, nenhuma significância (p > 0,05) foi observada nas interações entre tempo e grupo. Constatou-se efeito significativo (p = 0,001) do tempo sobre a EM para bíceps, tríceps e vasto lateral, sem diferenças significativas nas interações entre tempo e grupo. Correlações significativas foram encontradas entre força máxima e espessura muscular depois das análises estatísticas gerais para todos os protocolos. Conclusões A melhora da força máxima e da espessura muscular é semelhante quando o volume de repetições é equalizado considerando o número de séries e repetições. Nível de evidência I; Estudos terapêuticos, investigação dos resultados do tratamento.

RESUMEN Introducción Existen pocos estudios sobre la eficacia de modelos entrenamiento con conjuntos de alto volumen por sesión en grupos musculares específicos. Objetivos El objetivo del estudio fue investigar los efectos de diferentes repeticiones del entrenamiento de resistencia (ER) con volúmenes ecualizados en las adaptaciones musculares. Métodos Este estudio tiene diseño experimental con 47 voluntarios que realizaron ocho semanas de ER después de ser distribuidos aleatoriamente en tres grupos: diez series de tres repeticiones máximas (10x3), tres series de diez repeticiones máximas (3x10) y cinco series de seis repeticiones máximas (5x6) para cada grupo muscular por sesión de entrenamiento. La fuerza máxima (test de 1RM) y el espesor muscular (EM) fueron evaluados como conclusión. Resultados Se verificó efecto significativo (p = 0,001) sobre el tiempo en la fuerza máxima en los tres grupos, sin embargo, ninguna significancia (p> 0,05) fue observada en las interacciones entre tiempo y grupo. Se constató efecto significativo (p = 0,001) del tiempo sobre el EM para bíceps, tríceps y vasto lateral, sin diferencias significativas en las interacciones entre tiempo y grupo. Fueron encontradas correlaciones significativas entre fuerza máxima y espesor muscular después de los análisis estadísticos generales para todos los protocolos. Conclusiones La mejora de la fuerza máxima y del espesor muscular es semejante cuando el volumen de repeticiones es ecualizado considerando el número de series y repeticiones. Nivel de evidencia I; Estudios terapéuticos, investigación de los resultados del tratamiento.

Acute Behavior of Oxygen Consumption, Lactate Concentrations, and Energy Expenditure During Resistance Training: Comparisons Among Three Intensities.

Purpose: This study aimed to compare the oxygen consumption, lactate concentrations, and energy expenditure using three different intensities during the resistance training sessions. Methods: A total of 15 men (22.9 ± 2.61 years) experienced in resistance training underwent 3 sessions composed of 8 exercises (chest press, pec deck, squat, lat pull-down, biceps curl, triceps extension, hamstring curl, and crunch machine), which were applied in the same order. The weight lifted differed among the sessions [high session: 6 sets of 5 repetitions at 90% of 1-repetition maximum (1-RM); intermediary session: 3 sets of 10 repetitions at 75% of 1-RM; and low session: 2 sets of 15 repetitions at 60% of 1-RM]. The oxygen consumption (VO2)-during and after (excess post-exercise oxygen consumption (EPOC)) the session, blood lactate concentration, and energy expenditure (i.e., the sum of aerobic and anaerobic contributions, respectively) were assessed. Results: The VO2 significantly decreased in the function of the weight lifting (F (2.28) = 17.02; p < 0.01; η G 2 = 0.32). However, the aerobic contributions significantly increase in the function of the weight lifting (F (2.28) = 79.18; p < 0.01; η G 2 = 0.75). The anaerobic contributions were not different among the sessions (p > 0.05; η G 2 < 0.01). Thus, the total energy expenditure during the session (kcal) significantly increased in the function of the weight lifting (F (2.28) = 86.68; p < 0.01; η G 2 = 0.75). The energy expenditure expressed in time unit (kcal·min-1) was higher in low session than in high session (F (2.28) = 6.20; p < 0.01; η G 2 = 0.15). Conclusion: The weight lifted during resistance training-induced different physiological responses, which induced higher energy expenditure per unit of time during the low session.

Physical training attenuates right ventricular dysfunction in rats exposed to cigarette smoke

Abstract Aim: To evaluate the functional and morphological cardiac variables of rats exposed to chronic cigarette smoke (ECS) and to analyze the influence of exercise training on any cardiac remodeling. Methods: Male Wistar rats were assigned into four groups: control animals (C, n=10); control trained rats (CT, n=10), that underwent swimming physical training; ECS rats (E, n=10), that received the smoke of 40 cigarettes/day; and ECS plus trained rats (TE, n=10), that received the cigarette smoke plus the swimming training protocol, for 15 weeks. At the end of the experiment, the animals underwent hemodynamic measurements of the right ventricle (RV) and morphological examination. Results: There was a decrease in the body weight of E, TE and CT groups (p<0.05). RV pressure (maximum systolic, diastolic initial and end-diastolic) was increased in the E and ET groups (p <0.05), while there was a decrease in RV maximum derivative pressure, RV minimum derivative pressure (+dP/dt and -dP/dt) and systolic duration in the TE group (p <0.05). Heart rate increased in the E group (p<0.05). The lung weight/body weight ratio was higher in the TE group (p=0.008). Fluid retention was increased in the RV, left ventricle (LV) and lung of the E group (p<0.001). Conclusion: ECS caused right ventricular dysfunction, pulmonary hypertension and cardiac remodeling. Physical training attenuated the effects of ECS for heart rate responses and the morphological variables of the RV, LV, and the lung.

Effects of a Kinect-based physical training program on body composition, functional fitness and depression in institutionalized older adults.

Exergames have already been used as therapeutic tools to enhance both physical and cognitive functions in older adults. AIM: To evaluate the effects of a Kinect-based physical activity program on the quality of life, depression, functional fitness and body composition in institutionalized older adults. METHODS: A total of 50 older adults aged >60 years were selected and randomized to a control and video game group. Body composition was determined by means of anthropometric measurements. Quality of life was assessed using the WHOQOL-BREF questionnaire, and depression was classified using the Beck Depression inventory. Functional fitness was assessed using the Arm Curl, Chair Stand, 8-foot up-and-go, sit and reach, and the aerobic endurance test. RESULTS: After 12 weeks of protocol, we observed a significant improvement in all functional fitness parameters. CONCLUSIONS: Our findings suggest that a Kinect-based physical activity program seems to positively impact the three domains related to quality of life and directly associated with age (physical, social and psychological domains), and to promote a more active lifestyle in institutions housing older individuals. Geriatr Gerontol Int 2020; ••: ••-••.

Linear periodization of strength training in blocks attenuates hypertension and diastolic dysfunction with normalization of myocardial collagen content in spontaneously hypertensive rats.

BACKGROUND AND METHOD: This study evaluated the effects of a linear block strength training programme on the parameters of cardiac remodelling in spontaneously hypertensive rats. Thirty-nine rats were equally distributed in four groups: normotensive sedentary, normotensive trained, hypertensive sedentary and hypertensive trained. The strength training protocol was organized in three mesocycles of 4 weeks, with an increase in the training load organized in a linear fashion for each block, considering the weight established in the maximum loaded load test. The following parameters were evaluated: ventricular function assessed by echocardiogram, caudal blood pressure, ventricular haemodynamics and cardiac masses. Two-way analysis of variance was used to determine the differences between the group and time. RESULTS: After 12 weeks of training, the hypertensive trained group presented the following results: increased muscle strength, reduced blood pressure, reduced heart rate, isovolumetric relaxation time and total collagen content, with increased cardiac function, without promoting changes in the mass and nuclear volume of cardiomyocytes. Also, blood pressure reduction seems to be associated with both muscle strength adjustments and total load progress. CONCLUSION: The findings of this study showed that the training programme carried out attenuated systemic arterial pressure and preserved the ventricular function of spontaneously hypertensive rats without cardiac mass change.

Delayed Reperfusion-Coronary Artery Reperfusion Close to Complete Myocardial Necrosis Benefits Remote Myocardium and Is Enhanced by Exercise.

The present study aimed to analyze the effects of reperfusion of a distant coronary artery on cardiac function, the ultrastructure, and the molecular environment of the remote myocardium immediately after the completion of myocardial regional necrosis: delayed reperfusion (DR). Additionally, the effects of prior exercise on the outcomes of DR were investigated. Female rats with permanent occlusion or delayed reperfusion were randomly assigned to an exercise (swimming, 1 h/day, 5 days/week for 8 weeks) or sedentary protocol. Thus, the study included the following four groups: sedentary permanent occlusion, exercise permanent occlusion, sedentary delayed reperfusion, and exercise delayed reperfusion. The descending coronary artery was occluded for 1 h. Reperfusion was confirmed by contrast echocardiography, and the rats were observed for 4 weeks. Permanent occlusion and DR caused similar myocardial infarction sizes among the four groups. Interestingly, exercise significantly decreased the mortality rate. Delayed reperfusion resulted in significant benefits, including enhanced hemodynamics and papillary muscle contraction, as well as reduced apoptosis and collagen content. Protein calcium kinetics did not change. Meanwhile, developed tension and the Frank-Starling mechanism were enhanced, suggesting that calcium sensitivity was intensified in myofilaments. Remarkable remote myocardial benefits occurred after distant DR, and prior exercise intensified cardiac recovery. Our findings provide valuable information about DR. Our data might explain the better clinical outcomes in recent studies showing that late reperfusion could improve heart failure in patients with myocardial infarction. In conclusion, DR has remote myocardial benefits, including inotropism enhancement, pulmonary congestion reduction, and collagen and apoptosis attenuation, which are enhanced by prior exercise.

Interset Stretching vs. Traditional Strength Training: Effects on Muscle Strength and Size in Untrained Individuals.

Evangelista, AL, De Souza, EO, Moreira, DCB, Alonso, AC, Teixeira, CVLS, Wadhi, T, Rauch, J, Bocalini, DS, Pereira, PEDA, and Greve, JMDA. Interset stretching vs. traditional strength training: effects on muscle strength and size in untrained individuals. J Strength Cond Res 33(7S): S159-S166, 2019-This study compared the effects of 8 weeks of traditional strength training (TST) and interset stretching (ISS) combined with TST on muscular adaptations. Twenty-nine sedentary, healthy adults were randomly assigned to either the TST (n = 17; 28.0 ± 6.4 years) or ISS (n = 12; 26.8 ± 6.1 years) group. Both groups performed 6 strength exercises encompassing the whole body (bench press, elbow extension, seated rows, biceps curl, knee extension, and knee flexion) performing 4 sets of 8-12 repetition maximum (RM) with a 90-second rest between sets. However, the ISS group performed static passive stretching, at maximum amplitude, for 30 seconds between sets. Both groups performed training sessions twice a week on nonconsecutive days. Muscle strength (i.e., 1RM) and hypertrophy (i.e., muscle thickness [MT] by ultrasonography) were measured at pre-test and after 8 weeks of training. Both groups increased 1RM bench press (p ≤ 0.0001): ISS (23.4%, CIdiff: 4.3 kg-11.1 kg) and TST (22.2%, CIdiff: 5.2 kg-10.9 kg) and 1RM knee extension (p ≤ 0.0001): ISS (25.5%, CIdiff: 5.6 kg-15.0 kg) and TST (20.6%, CIdiff: 4.4 kg-12.3 kg). Both groups increased MT of biceps brachii (BIMT), triceps brachii (TRMT), and rectus femoris (RFMT) (p ≤ 0.0001). BIMT: ISS (7.2%, CIdiff: 1.14-3.5 mm) and TST (4.7%, CIdiff: 0.5-2.5 mm), TRMT: ISS (12.3%, CIdiff: 1.1-4.4 mm) and TST (7.1%, CIdiff: 0.3-3.1 mm), and RFMT: ISS (12.4%, CIdiff: 1.1-2.9 mm) and TST (9.1%, CIdiff: 0.7-2.2 mm). For vastus lateralis muscle thickness (VLMT) and sum of the 4 muscle thickness sites (ΣMT), there was a significant group by time interaction (p ≤ 0.02) in which ISS increased VLMT and ΣMT to a greater extent than TST. Vastus lateralis muscle thickness: ISS (17.0%, CIdiff: 1.5-3.1 mm) and TST (7.3%, CIdiff: 0.7-2.1 mm), and ΣMT: ISS (10.5%, CIdiff: 6.5-9.0 mm) and TST (6.7%, CIdiff: 3.9-8.3 mm). Although our findings might suggest a benefit of adding ISS into TST for optimizing muscle hypertrophy, our data are not sufficient enough to conclude that ISS is superior to TST for inducing muscle hypertrophic adaptations. More studies are warranted to elucidate the effects of ISS compared with TST protocols on skeletal muscle. However, our findings support that adding ISS to regular TST regimens does not compromise muscular adaptations during the early phase of training (<8 weeks) in untrained individuals.