Effects of Aquatic Exercise on Muscle Strength in Young and Elderly Adults: A Systematic Review and Meta-Analysis of Randomized Trials.

ABSTRACT: Prado, AKG, Reichert, T, Conceição, MO, Delevatti, RS, Kanitz, AC, and Kruel, LFM. Effects of aquatic exercise on muscle strength in young and elderly adults: a systematic review and meta-analysis of randomized trials. J Strength Cond Res 36(5): 1468-1483, 2022-The effects of training in an aquatic environment on muscular strength are still contradictory in the literature. The aim was to conduct a systematic review and meta-analysis of randomized studies about muscle strength responses after a program of aquatic exercise. A systematic review followed the Cochrane and PRISMA recommendations. The search was performed between December 2015 and January 2016. There were no language restrictions, and PubMed, SCOPUS, Scielo, Cochrane, and PEDro databases were consulted. An analysis of eligibility of the studies was performed by 2 independent authors. The data extraction followed standard criteria, and an evaluation of methodological quality was performed. The statistical analysis was conducted in the Review Manager 5.1 software. The statistical heterogeneity was assessed by means of Cochran's Q test and by the inconsistency test (I2). The search found 2,563 articles, 27 were included, totaling a total n of 1,006 subjects. The analysis of the risk of bias demonstrated a lack of clarity of the randomization process, allocation concealment, blinding assessment, intention to treat analysis, and calculation of the sample in 70% or more of the studies analyzed. Meta-analysis demonstrated a significant increase in handgrip strength, in isometric peak torque (PT) of knee unilateral extension and flexion, and isokinetic PT (60°·s-1) of knee unilateral extension. Sensitivity analyses demonstrated that the positive effects of training in an aquatic environment may be dependent on factors such as age, velocity of movement, and use of device. Land-based and aquatic exercises seem to lead to similar muscle strength gains. Aquatic exercise should be recommended as a strategy to improve muscle strength, but new studies with better methodological quality should be conducted.

A comparison of the internal and external load demands imposed on professional soccer referees in FIFA's current model of physical test in relation to games.

BACKGROUND: Based on the need to investigate the demands imposed on referees in the current model of physical evaluation and during professional games, this study's objective was to compare these demands in the physical test versus the games. METHODS: Thus, it evaluated the heart rate, distance covered, time, and speed of all 14 referees in the physical test and during Brazil's first division state championship games using a Global Positioning System enabled heart rate monitor. RESULTS: The maximum heart rate (HRmax) and maximum speed were higher in the physical test (183.86±12.79 bpm) and (26.80±0.96 km/h), respectively, than in the games (170.25±17.71 bpm) (P=0.008) and (24.27±1.68 km/h) (P=0.001), respectively. In the HRmax zone ≥90 and ≤100%, the time and percentage distance were greater in the physical test (47.87±16.60% and 58.57±22.78%), respectively, than in the games (17.82±18.29% and 18.84±18.92%, respectively; P<0.001). However, in the speed zone <13 km/h, the time and the percentage distance were longer in the game (93.73±1.26% and 86.13±2.31%), respectively, than in the physical test (68.73±12.31% and 39.65±9.74%, respectively; P<0.001). CONCLUSIONS: Thus, it is concluded that the professional referees perform at greater intensities during the physical test than in the games. In contrast, the demands for intensities corresponding to aerobic metabolism are greater in games or equal to those in physical testing, depending on the intensity reference.

Water-Based Aerobic and Resistance Training as a Treatment to Improve the Lipid Profile of Women With Dyslipidemia: A Randomized Controlled Trial.

Background: Regular exercise is recommended for the treatment of dyslipidemia. The aquatic environment presents some beneficial characteristics for patients suffering from dyslipidemia. However, it is unknown which modality promotes better results. This study aims to compare the effects of water-based aerobic training (WA) and water-based resistance training (WR) on lipid profile of dyslipidemic elderly women. Methods: Sixty-nine dyslipidemic elderly women participated in this 3-arm randomized controlled clinical trial with groups in parallel. The interventions were WA, WR, and control group, with 2 weekly sessions for 10 weeks. Total cholesterol (TC), triglycerides, low-density lipoprotein, high-density lipoprotein (HDL) levels, and TC/HDL ratio, were determined before and after interventions. Results: Intention-to-treat analysis showed that WA and WR participants obtained similar decreases in TC (-10.0% and -9.6%, respectively), triglycerides (-13.4% and -15.7%, respectively), low-density lipoprotein (-16.1% and -16.9%, respectively), TC/HDL (-16.9% and -23.4%, respectively) and increases in HDL (7.6% and 16.9%, respectively). The control group maintained their TC and low-density lipoprotein levels unchanged, whereas triglycerides and TC/HDL were increased (3.6% and 11.3%, respectively), and HDL decreases 4.8%. Conclusions: WA and WR improve similarly the lipid profile of dyslipidemic elderly women, representing interesting nonpharmacological tools in the treatment of dyslipidemia.

Muscle Damage and Muscle Activity Induced by Strength Training Super-Sets in Physically Active Men.

Brentano, MA, Umpierre, D, Santos, LP, Lopes, AL, Radaelli, R, Pinto, RS, and Kruel, LFM. Muscle damage and muscle activity induced by strength training super-sets in physically active men. J Strength Cond Res 31(7): 1847-1858, 2017-In strength training, muscle activity is often analyzed by surface electromyography (EMG) and muscle damage through indirect markers, such as plasma concentrations of creatine kinase (CK) after exercise. However, there is little information about the influence of the strength exercises order on these parameters. The purpose of this study is to analyze the effect of strength exercises order (super-sets) in muscle activity and indirect markers of muscle damage. Twenty men were randomly assigned to one of the strength training sessions (TS). Each TS (5 sets × 8-10 repetition maximum) consisted of 2 exercises for the knee extensor muscles and 2 exercises for the horizontal shoulder flexors performed in a different order: exercises for the same muscle group grouped (grouped exercises [GE]: n = 10; 26.6 ± 3.4 years; 17.4 ± 3.4 body fat) or separated (separated exercises [SE]: n = 10; 24.9 ± 2.6 years; 15.4 ± 5.9 body fat). Muscle activity was analyzed by surface EMG (vastus lateralis [VL], vastus medialis [VM], rectus femoris [RF], pectoralis major [PM], and anterior deltoid [AD]), and the main indirect marker of muscle damage was the CK, evaluated immediately before and after the first 5 days of each TS. There was a higher EMG activity of GE in the RF (GE: 88.4% × SE: 73.6%) and AD (GE: 176.4% × SE: 100.0%), in addition to greater concentration of CK (GE: 632.4% × SE: 330.5%) after exercise. Our findings suggest that, in physically active men, implementing super-sets with GE promotes greater muscle effort and muscle damage, wherein 5 days are not enough to recover the trained muscle groups.

Active Female Maximal and Anaerobic Threshold Cardiorespiratory Responses to Six Different Water Aerobics Exercises.

PURPOSE: Maximal tests conducted on land are not suitable for the prescription of aquatic exercises, which makes it difficult to optimize the intensity of water aerobics classes. The aim of the present study was to evaluate the maximal and anaerobic threshold cardiorespiratory responses to 6 water aerobics exercises. Volunteers performed 3 of the exercises in the sagittal plane and 3 in the frontal plane. METHOD: Twelve active female volunteers (aged 24 ± 2 years) performed 6 maximal progressive test sessions. Throughout the exercise tests, we measured heart rate (HR) and oxygen consumption (VO2). We randomized all sessions with a minimum interval of 48 hr between each session. For statistical analysis, we used repeated-measures 1-way analysis of variance. RESULTS: Regarding the maximal responses, for the peak VO2, abductor hop and jumping jacks (JJ) showed significantly lower values than frontal kick and cross-country skiing (CCS; p < .001; partial η(2) = .509), while for the peak HR, JJ showed statistically significantly lower responses compared with stationary running and CCS (p < .001; partial η(2) = .401). At anaerobic threshold intensity expressed as the percentage of the maximum values, no statistically significant differences were found among exercises. CONCLUSION: Cardiorespiratory responses are directly associated with the muscle mass involved in the exercise. Thus, it is worth emphasizing the importance of performing a maximal test that is specific to the analyzed exercise so the prescription of the intensity can be safer and valid.

Nonsteroidal anti-inflammatory drug use and endurance during running in male long-distance runners.

CONTEXT: The effect of ibuprofen on pain tolerance during exercise is controversial, and its effects on endurance performance have been poorly investigated. OBJECTIVE: To investigate the effect of prophylactic administration of the nonsteroidal anti-inflammatory drug ibuprofen on the time until the self-report of fatigue (tlim) in runners with exercise-induced muscle damage. DESIGN: Randomized controlled clinical trial. SETTING: Laboratory. PATIENTS OR OTHER PARTICIPANTS: Twenty healthy male long-distance runners (age = 18.8 ± 0.4 years, maximal oxygen consumption = 55.5 ± 5.9 mL·kg(-1)·min(-1)). INTERVENTION(S): Participants were assigned to 2 groups (ibuprofen group = 10, placebo group = 10) to perform tlim trials (speed corresponded to their previously determined secondventilatory thresholds) 48 hours before and 48 hours after the induction of a lower limb muscle-damage protocol (isokinetic dynamometry). One hour before the second tlim trial, the ibuprofen group received 1.2 g ibuprofen, and the placebo group received lactose orally. MAIN OUTCOME MEASURE(S): Time until self-reported fatigue, heart rate, respiratory quotient, oxygen consumption, and perceived exertion were recorded during each tlim test. RESULTS: Both groups reported increases in muscle pain in the knee extensors and flexors 48 hours after the muscle-damage protocol. We observed a reduction in the endurance performance of both groups (P < .01) but no difference between groups (P = .55). CONCLUSIONS: Ibuprofen did not reduce the effect of muscle damage and pain on performance. Prophylactic use of nonsteroidal anti-inflammatory drugs did not have an ergogenic effect on running performance after exercise-induced muscle damage in male long-distance runners.

Water-Based Concurrent Training Improves Peak Oxygen Uptake, Rate of Force Development, Jump Height, and Neuromuscular Economy in Young Women.

The study investigated the effects of different intrasession exercise sequences on the cardiorespiratory and neuromuscular adaptations induced by water-based concurrent training in young subjects. Twenty-six healthy young women (25.1 ± 2.9 years) were placed into 2 water-based concurrent training groups: resistance before (RA, n = 13) or after (AR, n = 13) aerobic training. Subjects trained resistance and aerobic training during 12 weeks, 2 times per week performing both exercise types in the same training session. Peak oxygen uptake (V[Combining Dot Above]O2peak), rate of force development (RFD) obtained during an isometric peak torque knee extension protocol, jump height, and neuromuscular economy (normalized electromyography at 80% of pretraining knee extension isometric peak torque) in young women were determined. After training, there was a significant increase (p < 0.001) in both RA and AR in the V[Combining Dot Above]O2peak, with no differences between groups (7 vs. 5%). The maximal isometric knee extension RFD showed significant increases (p = 0.003) after training (RA: 19 vs. AR: 30%), and both groups presented similar gains. In addition, the countermovement jump height also increased (p = 0.034) after training (RA: 5% vs. AR: 6%), with no difference between groups. After training, there were significant improvements on vastus lateralis (p < 0.001) (RA: -13% vs. AR: -20%) and rectus femoris (p = 0.025) (RA: -17% vs. AR: -7%) neuromuscular economy, with no difference between groups. In conclusion, 12 weeks of water-based concurrent training improved the peak oxygen uptake, RFD, jump height, and neuromuscular economy in young women independent from the intrasession exercise sequence.

Cardiorespiratory responses of pregnant and nonpregnant women during resistance exercise.

The purpose of this study was to determine cardiorespiratory responses in pregnant and nonpregnant women during the execution of resistance exercises for upper and lower body. Twenty healthy women (10 pregnant: 22-24 weeks, 25.20 ± 4.44 years, 69.80 ± 9.52 kg, 161.60 ± 5.21 cm and 10 nonpregnant: 25.20 ± 3.73 years, 62.36 ± 8.60 kg, 162.40 ± 3.97 cm) performed 5 experimental sessions. Session 1: familiarization with the equipments and the determination of 1 estimated maximum repetition. Sessions 2, 3, 4, and 5: determination of the cardiorespiratory responses during the execution of resistance exercise on the bilateral leg extension and pec-deck fly, with 1 and 3 sets of 15 repetitions, 50% of 1 estimated maximum repetition. Systolic, diastolic, and mean blood pressure (BP) responses were lower (p = 0.029, 0.018, 0.009, respectively) in the pregnant group. When the exercises were performed with a single set, heart rate showed increased values for bilateral leg extension (pregnant: 109.40 ± 10.75 b·min, nonpregnant: 108.51 ± 19.05 b·min) compared with pec-deck (pregnant: 101.59 ± 14.83 b·min, nonpregnant: 100.37 ± 12.36 b·min); however, when the exercises were performed with 3 sets, bilateral leg extension showed increased values for the heart rate (pregnant: 114.70 ± 13.58 b·min, nonpregnant: 121.29 ± 10.86 b·min), systolic (pregnant: 124.50 ± 17.32 mm Hg, nonpregnant: 136.00 ± 17.79 mm Hg), diastolic (pregnant: 68.10 ± 8.23 mm Hg, nonpregnant: 77.89 ± 15.25 mm Hg), and mean BP (pregnant: 86.90 ± 10.38 mm Hg, nonpregnant: 97.73 ± 12.64 mm Hg), ventilation (pregnant: 12.88 ± 4.05 L·min, nonpregnant: 15.02 ± 4.19 L·min), and oxygen consumption (pregnant: 0.41 ± 0.08 L·min, nonpregnant: 0.42 ± 0.09 L·min) compared with pec-deck fly exercise. We concluded that the pressure response was unaffected by pregnancy and showed to be safe during the performance of resistance exercises.

Maximal and ventilatory thresholds cardiorespiratory responses to three water aerobic exercises compared with treadmill on land.

The purpose of this study was to compare the cardiorespiratory responses of young women to exercise at the first ventilatory threshold (VT1), the second ventilatory threshold (VT2), and at maximum effort (MAX) between maximal incremental tests performed using water aerobic exercises and a treadmill on land (TL). Twenty women (24.0 ± 2.5 years; 163.3 ± 6.7 cm; 60.0 ± 6.7 kg) underwent 4 maximal tests in randomized order, with a 48-hour interval between tests. Three tests involved performing water aerobic exercises (stationary running, frontal kick, and cross-country skiing) and 1 TL. Oxygen uptake (VO2), ventilation (VE), and heart rate were measured throughout the tests, and their values at the VT1, VT2, and MAX intensities were determined by 3 independent, experienced physiologists. Repeated measures analysis of variance with Bonferroni post hoc tests were used for comparisons between tests (α = 0.05). Heart rate was significantly higher in the TL condition compared with the water aerobic exercises at the VT1 (p = 0.001), VT2 (p < 0.001), and MAX (p < 0.001) intensities. VO2 and VE had similar values across the 4 protocols at the VT1 intensity, but significantly higher values were observed with TL (VO2: p < 0.001; VE: p < 0.001) at the VT2 intensity. At the MAX intensity, VO2 was significantly higher with TL compared with the 3 water aerobic exercises (p < 0.001), whereas no significant differences in VE between the 4 protocols were found. These results suggest that the prescription of water aerobics classes should be based on specific maximal tests for water aerobic exercises. Training intensities could be overestimated if they were based on maximal tests on dry land.

Using heart rate to prescribe physical exercise during head-out water immersion.

The purpose of this study was to compare and correlate the effect of age group, sex, depth of water immersion, and the heart rate (HR) assessed out of the water on the HR behavior in individuals subjected to head-out water immersion. A total of 395 healthy individuals of both sexes, aged between 07 and 75 years, underwent vertical head-out water immersion. Heart rate was assessed out of the water in the supine and orthostatic (OHR) positions and at immersion depths corresponding to the ankle, knee, hip, umbilicus, xiphoid process, acromion, neck, and also the neck with the arms out of the water. The formula (ΔHR = OHR - HR immersion depth) was used to calculate the reduction in HR at each immersion depth. No age-based or sex-based differences in HR were found. The greater the depth of the water, the greater was the decrease in HR (p < 0.05); however, no differences were found between the HR values obtained below the depth corresponding to the umbilicus. Similarly, there was a significant relationship between OHR and ΔHR measured at levels below the depth corresponding to the umbilicus (e.g., xiphoid process level: r = 0.62; p < 0.05). Therefore, this study suggests to appropriately prescribe the intensity of water-based exercise intensity performed during vertical immersion: OHR should be measured before the individual entering the aquatic environment; ΔHR should be measured according to the depth at which exercise is to be performed, and we suggest an adaptation to Karvonen's HRmax prediction formula (predicted HRmax: 220 - age - ΔHR) to prescribe and control the intensity of the exercise performed during vertical immersion.

Neuromuscular responses during aquatic resistance exercise with different devices and depths.

Little research has been reported regarding the effects of using different devices and immersion depths during the performance of resistance exercises in a water environment. The purpose of this study was to compare muscular activation of upper extremity and core muscles during shoulder extensions performed at maximum velocity with different devices and at different depths. Volunteers (N = 24) young fit male university students performed 3 repetitions of shoulder extensions at maximum velocity using 4 different devices and at 2 different depths. The maximum amplitude of the electromyographic root mean square of the latissimus dorsi (LD), rectus abdominis, and erector lumbar spinae was recorded. Electromyographic signals were normalized to the maximum voluntary isometric contraction. No significant (p > 0.05) differences were found in the neuromuscular responses between the different devices used during the performance of shoulder extension at xiphoid process depth. Regarding the comparisons of muscle activity between the 2 depths analyzed in this study, only the LD showed a significantly (p ≤ 0.05) higher activity at the xiphoid process depth compared with that at the clavicle depth. Therefore, if maximum muscle activation of the extremities is required, the xiphoid depth is a better choice than clavicle depth, and the kind of device is not relevant. Regarding core muscles, neither the kind of device nor the immersion depth modifies muscle activation.

Maximal and ventilatory thresholds of oxygen uptake and rating of perceived exertion responses to water aerobic exercises.

This study aimed to compare the V[Combining Dot Above]O2max and first and second ventilatory threshold (1stVT and 2ndVT) V[Combining Dot Above]O2 values and rating of perceived exertion (RPE) responses of treadmill running (TR) with those of 3 water aerobic exercises: stationary running (SR), jumping jack (JJ), and forward kick (FK). Nine women (22.89 ± 1.81 years, 1.66 ± 0.07 m, 58.46 ± 4.19 kg) performed 1 maximal test session for each of the 4 exercise protocols in a randomized order to determine the V[Combining Dot Above]O2max and V[Combining Dot Above]O2 values and RPE responses corresponding with the 1stVT and 2ndVT. V[Combining Dot Above]O2 values were also expressed as a percentage of V[Combining Dot Above]O2max (%V[Combining Dot Above]O2max). A repeated measures analysis of variance and Bonferroni's post hoc test were used, with α = 0.05 denoting statistical significance. The analyses showed that the V[Combining Dot Above]O2 responses were significantly higher for TR than for the other exercises at all effort intensities (V[Combining Dot Above]O2max: p < 0.001; 1stVT and 2ndVT V[Combining Dot Above]O2: p < 0.001), followed by intermediate responses for SR and FK and lower responses for JJ. However, no significant differences between exercises for values of %V[Combining Dot Above]O2max (1stVT: p = 0.099; 2ndVT: p = 0.131) and RPE (1stVT: p = 0.275; 2ndVT: p = 0.477) were found at submaximal intensities, indicating that it is possible to achieve and maintain the same training intensity with these exercises during a typical water fitness lesson. Moreover, the RPE values obtained for the 1stVT and 2ndVT can make the prescription of intensity for these water exercises for young women more simple and practical.

Síndrome metabólica em adolescentes obesos: comparação entre três diferentes critérios diagnósticos / Metabolic syndrome in obese adolescents: a comparison of three different diagnostic criteria

OBJETIVO: Verificar a diferença na proporção de adolescentes com síndrome metabólica, diagnosticados por três diferentes critérios, bem como com a utilização da resistência à insulina no lugar da glicemia de jejum. MÉTODOS: Estudo transversal com 121 adolescentes obesos, de 10 a 14 anos de idade, da rede municipal de ensino de Porto Alegre, em 2011. Foram realizadas avaliações antropométricas, de pressão arterial e bioquímicas. A síndrome metabólica foi definida por três critérios diagnósticos diferentes: International Diabetes Federation, Cook e de Ferranti. Todos eles incluem cinco componentes: perímetro abdominal, pressão arterial, lipoproteína de alta densidade (HDL) colesterol, triglicerídeos e glicemia em jejum, sendo necessária a alteração de pelo menos três para o diagnóstico da síndrome. Para a caracterização da resistência à insulina, foi utilizado o índice Homeostasis Model Assessment - Insulin Resistance. A análise de concordância entre os critérios foi realizada pela estatística de Kappa. RESULTADOS: A síndrome metabólica foi observada em 39,7, 51,2 e 74,4% dos adolescentes, de acordo com as definições da International Diabetes Federation, Cook e de Ferranti, respectivamente. Houve concordância do diagnóstico para os três critérios, simultaneamente, em 60,3% da amostra. O componente mais prevalente foi o perímetro abdominal elevado (81,0, 81,0 e 96,7%), e o menos prevalente foi a glicemia em jejum elevada (7,4, 1,7 e 1,7%). A utilização do Homeostasis Model Assessment - Insulin Resistance aumentou significativamente a proporção de diagnósticos positivos para a síndrome. CONCLUSÃO: Os resultados mostraram considerável diferença entre os três critérios diagnósticos. Enquanto não houver consenso em relação aos critérios da síndrome metabólica, serão frequentes as divergências quanto à prevalência da doença em populações pediátricas.

OBJECTIVE: To investigate the difference in the proportion of adolescents with metabolic syndrome diagnosed based on three different criteria, as well as the use of insulin resistance instead of fasting glucose. METHODS: Cross-sectional study with 121 obese adolescents, between 10 and 14 years old, from public schools of the city of Porto Alegre, Brazil, in 2011. Anthropometric, blood pressure, and biochemical variables were assessed. Metabolic syndrome was defined using three different diagnostic criteria: the International Diabetes Federation (IDF), Cook and de Ferranti. All of them include five components: waist circumference, blood pressure, high-density lipoprotein (HDL) cholesterol, triglycerides and fasting glucose, and there should be at least three abnormal results for the diagnosis of the syndrome. The Homeostasis Model Assessment - Insuline Resistance (HOMA-IR) was used for the characterization of insulin resistance. The analysis of agreement among the criteria was performed using Kappa statistics. RESULTS: Metabolic syndrome was diagnosed in 39.7, 51.2, and 74.4% of adolescents, according to the IDF, Cook and de Ferranti criteria, respectively. There was agreement for the three diagnostic criteria in 60.3% of the sample. Waist circumference was the most prevalent component (81.0, 81.0, and 96.7%), whereas high fasting glucose was the least prevalent (7.4, 1.7, and 1.7%). The use of HOMA-IR significantly increased the proportion of positive diagnoses for the syndrome. CONCLUSION: The results showed significant differences between the three diagnostic criteria. While there is no consensus on the diagnostic criteria for metabolic syndrome, differences in the prevalence of the disease in pediatric population will be frequent.

Metabolic syndrome in obese adolescents: a comparison of three different diagnostic criteria.

OBJECTIVE: To investigate the difference in the proportion of adolescents with metabolic syndrome diagnosed based on three different criteria, as well as the use of insulin resistance instead of fasting glucose. METHODS: Cross-sectional study with 121 obese adolescents, between 10 and 14 years old, from public schools of the city of Porto Alegre, Brazil, in 2011. Anthropometric, blood pressure, and biochemical variables were assessed. Metabolic syndrome was defined using three different diagnostic criteria: the International Diabetes Federation (IDF), Cook and de Ferranti. All of them include five components: waist circumference, blood pressure, high-density lipoprotein (HDL) cholesterol, triglycerides and fasting glucose, and there should be at least three abnormal results for the diagnosis of the syndrome. The Homeostasis Model Assessment - Insuline Resistance (HOMA-IR) was used for the characterization of insulin resistance. The analysis of agreement among the criteria was performed using Kappa statistics. RESULTS: Metabolic syndrome was diagnosed in 39.7, 51.2, and 74.4% of adolescents, according to the IDF, Cook and de Ferranti criteria, respectively. There was agreement for the three diagnostic criteria in 60.3% of the sample. Waist circumference was the most prevalent component (81.0, 81.0, and 96.7%), whereas high fasting glucose was the least prevalent (7.4, 1.7, and 1.7%). The use of HOMA-IR significantly increased the proportion of positive diagnoses for the syndrome. CONCLUSION: The results showed significant differences between the three diagnostic criteria. While there is no consensus on the diagnostic criteria for metabolic syndrome, differences in the prevalence of the disease in pediatric population will be frequent.

Effects of strength, endurance, and concurrent training on aerobic power and dynamic neuromuscular economy in elderly men.

The aim of this study was to investigate the effects of concurrent training on endurance capacity and dynamic neuromuscular economy in elderly men. Twenty-three healthy men (65 ± 4 years) were divided into 3 groups: concurrent (CG, n = 8), strength (SG, n = 8), and aerobic training group (EG, n = 7). Each group trained 3 times a week for 12 weeks, strength training, aerobic training, or both types of training in the same session. The maximum aerobic workload (Wmax) and peak oxygen uptake (VO2peak) of the subjects were evaluated on a cycle ergometer before and after the training period. Moreover, during the maximal test, muscle activation was measured at each intensity by means of electromyographic signals from the vastus lateralis (VL), rectus femoris (RF), biceps femoris long head, and gastrocnemius lateralis to determine the dynamic neuromuscular economy. After training, significant increases in VO2peak and Wmax were only found in the CG and EG (p < 0.05), with no difference between groups. Moreover, there was a significant decrease in myoelectric activity of the RF muscle at 50 (EG), 75 and 100 W (EG and CG) and in the VL for the 3 groups at 100 W (p < 0.05). No change was seen in the electrical signal from the lateral gastrocnemius muscle and biceps femoris. The results suggest specificity in adaptations investigated in elderly subjects, because the most marked changes in the neuromuscular economy occurred in the aerobically trained groups.

The effects of resistance training performed in water on muscle strength in the elderly.

The purpose of the present study was to compare the effects of a program of resistance training in water-based exercises (RWE) with those of a program without resistance control in water-based exercises (WEs). Twenty-seven women (aged 60-74 years) were randomly assigned to the RWE group (n = 10), WE group (n = 10), or nontraining control (CON) group (n = 7). The RWE and WE groups trained classes with aerobic exercises and localized muscular resistance exercises for 50 minutes, twice a week for 12 weeks. For the RWE group, the program included 4 mesocycles of 3 weeks-respectively, 4 sets of 15 repetitions, 4 sets of 12 repetitions, 5 sets of 10 repetitions, and 5 sets of 8 repetitions-of shoulder horizontal flexion exercise at maximum speed, with the use of resistive equipment. For the WE group, the training was not periodized, and the resistance in the localized muscular exercises was not controlled. One repetition maximum (1RM) was measured on a pectoral fly machine at baseline and after the training period. The level of significance adopted was p ≤ 0.05. The results showed that the only significant increase in 1RM (10.89%, p < 0.001) occurred in the RWE group after training. In conclusion, these findings suggest that WEs with emphasis on resistance training in a periodized program can efficiently increase maximum strength in elderly women. Thus, it is suggested that the strategies used in WE programs be modified to offer suitable stimuli for the development of strength.

Perceived exertion in different strength exercise loads in sedentary, active, and trained adults.

The aim was to analyze the relationship between the perceived exertion (PE) and different loads in strength exercises (SEs), in sedentary, active, and trained adult subjects. Thirty young men (18-34 years) were divided into 3 groups (experimental group [EG]): sedentary EG (SEG), physically active group (PAG), and the strength trained group (STG). Maximum strength was established using the 1 repetition maximum test (1RM). Using series of 12 repetitions, different loads were applied until the 4 ratings of PE (RPEs) (11, 13, 15, and 17) from 15 category Borg Perceived Exertion Scale (RPE 6-20). The pace of the repetitions and the intervals between the sets were controlled, the loads were blind, the order of the RPE randomized, whereas the PE was localized and determined after completion of the series. Strength correlations between the RPE and the %1RM, according to the EGs and SEs (0.826-0.922, p < 0.001), were observed. Similar behavior was seen in the SEs. Higher loads are related to higher RPEs and are differentiated between the EGs. The STG used higher %1RM when compared to the SEG, whereas the PAG, displayed an intermediary behavior in relation to the other groups. The use of PE represents a reliable instrument for the measurement of intensity in strength training.

Effect of resistive exercise on muscle damage in water and on land.

The purpose of this study was to compare the effects of resistance exercise in water and on land on blood levels of creatine kinase (CK), a known indirect marker of muscle damage. Nine men (age: 23 +/- 1.58 years; weight: 79.37 +/- 11.15 kg; height: 176.33 +/- 4.09 cm), who had not practiced resistance training for at least 6 months before this experiment, performed 3 sets of maximum elbow flexion and extension exercises in water and on land, separated by 2-minute periods of rest. A 10-repetition maximum test was used to load control on land with free weights, and in water the exercise was performed at maximum velocity with aquatic resistance equipment. The duration of the exercise in water was the same as that performed on land, to reproduce the same metabolic route. Plasma CK activity was determined using a commercially available kit (Labtest Enzymatic-UV) before exercise, after exercise, and at 24 and 48 hours after exercise. Significant increases in CK were found at 48 hours postexercise on land (preexercise land: 160.75 +/- 96.05 UxL; 48 hours: 326.87 +/- 240.84 UxL), and significant differences were found between land and water (preexercise water: 147.75 +/- 46.48 UxL; 48 hours: 121.75 +/- 30.86 UxL) for this measure. However, no significant differences were found in water. In conclusion, the water environment influenced the absence of significant muscle damage. This type of exercise protocol may be appropriate for situations in which limited muscle tissue damage is desired.

Physiological adaptations to strength and circuit training in postmenopausal women with bone loss.

Strength training (ST; high intensity/low volume/long rest) has been used in several populations, including children, young adults, and older adults. However, there is no information about circuit weight training (CWT; low intensity/high volume/short rest) in apparently healthy postmenopausal women. The purpose of the present study was to analyze the effects of high-intensity ST and circuit training on isometric strength (IS), upper limb dynamic strength (ULS) and lower limb dynamic strength (LLS), muscle activation of quadriceps (EMG quad), maximal oxygen uptake (VO2 max), time to exhaustion (TE), and bone mineral density (BMD). Twenty-eight postmenopausal women were divided into 3 groups: 1) ST group (STG, n = 9, 45-80% 1 repetition maximum (1RM), 2-4 sets, 20-6 reps), 2) circuit training group (CTG, n = 10, 45-60% 1RM, 2-3 sets, 20-10 reps), and 3) a control group (CON, n = 9, no exercise). Significance level was defined as p