Repetition Maximum Test Research Articles

THE EFFECTS OF THREE WEEKS OF TIME-RESTRICTED EATING WITH RESISTANCE TRAINING ON MUSCULAR STRENGTH IN COLLEGE AGED ADULTS

Time-restricted eating (TRE) has shown to have a multitude of benefits individual’s overall health such as reducing the risk for cardiovascular disease and promoting weight loss. However, there is limited data on effects of TRE on muscular strength. PURPOSE: The current study examined the effects of TRE with resistance training (RT) on muscular strength in college-aged adults. METHODS: Eleven healthy college-aged adults between the ages of 18-21 years, volunteered to complete a 3-week RT. The subjects were randomly assigned into either control group (CG) or experimental group (EG). The CG performed the RT workout 3 days a week with normal diet for three weeks. The EG performed the RT workout 3 days a week with TRE diet that allowed subjects to consume food between 11 am and 8 pm for three weeks. Body weight measurement and one repetition maximum test for bench press and back squat were administered at baseline and post-intervention. All data were analyzed by a 2 (group) x 2 (time) ANOVA with repeated measure (p < 0.05). The Bonferroni pairwise comparisons were conducted as post hoc to locate the significant mean differences. RESULTS: Either CG or EG did not significantly change muscular strength and body weight. CONCLUSIONS: Three weeks of TRE with resistant training did not enhance muscular strength. This research can be used for a guide for those interested in their muscular fitness goals. The long-term effects of the TRE diet on muscular strength should be further explored in future studies.

Ischemic Preconditioning with High and Low Pressure Enhances Maximum Strength and Modulates Heart Rate Variability.

Background: The application of ischemic preconditioning (IPC) to resistance exercise has attracted some attention, owing to increases in muscle performance. However, there is still no consensus on the optimal occlusion pressure for this procedure. This study compared the acute effects of IPC with high and low pressure of occlusion on upper and lower limb maximal strength and heart rate variability in recreationally trained individuals. Methods: Sixteen recreationally trained men (25.3 ± 1.7 years; 78.4 ± 6.2 kg; 176.9 ± 5.4 cm; 25.1 ± 1.5 m2 kg−1) were thoroughly familiarized with one repetition maximum (1 RM) testing in the following exercises: bench press (BP), front latissimus pull-down (FLPD), and shoulder press (SP) for upper limbs, and leg press 45º (LP45), hack machine (HM), and Smith Squat (SS) for lower limbs. The 1 RM exercises were then randomly performed on three separate days: after a high pressure (220 mmHg, IPChigh) and a low pressure (20 mmHg, IPClow) IPC protocol and after no intervention (control, CON). Heart rate variability was also measured at rest, during and after the entire IPC protocol, and after the exercises. Results: Maximal strength was significantly (p < 0.05) higher in both IPChigh and IPClow compared with CON in all upper- and lower-limb exercises. There was no difference between the two experimental conditions. No significant differences were found in the comparison across the different experimental conditions for LFnu, HFnu, LF/HF ratio, and RMSSDms. Conclusions: IPC performed with both high and low pressures influenced heart rate variability, which may partly explain the maximal strength enhancement.

Effect of physical exercise on muscle strength in adults following bariatric surgery: A systematic review and meta-analysis of different muscle strength assessment tests.

Individuals following bariatric surgery are considered at high risk for the development of sarcopenic obesity (excess fat mass, low muscle mass and low physical function), and exercise may play an important role in its prevention and treatment. We systematically reviewed 5 scientific databases (Embase, Medline, Scopus, SPORTDiscus, and Web of Science) and 2 grey literature databases (ProQuest and Google Scholar) for clinical trials that evaluated the effect of exercise on muscle strength in adults following bariatric surgery and conducted a separate meta-analysis for studies that used different muscle strength tests. Random-effect models, restricted maximum likelihood method and Hedges’ g were used. The review protocol was registered at the International Prospective Register of Systematic Reviews (PROSPERO) database (CRD42020152142). Fifteen studies were included (638 patients), none had a low risk of bias, and all were included in at least 1 of the 5 meta-analyses (repetition maximum [lower and upper limbs], sit-to-stand, dynamometer, and handgrip tests). Exercise interventions improved both upper (effect size, 0.71; 95% CI, 0.41–1.01; I2 = 0%) and lower (effect size, 1.37; 95% CI, 0.84–1.91; I2 = 46.14) limb muscle strength, as measured by repetition maximum tests. Results were similar for the sit-to-stand (effect size, 0.60; 95% CI, 0.20–1.01; I2 = 68.89%) and dynamometer (effect size, 0.46; 95% CI, 0.06–0.87; I2 = 31.03%), but not for the handgrip test (effect size, 0.11; 95% CI, -0.42–0.63; I2 = 73.27%). However, the certainty level of the meta-analyses was very low. Exercise with a resistance training component performed post bariatric surgery may improve muscle strength, which is related to sarcopenic obesity, functional capacity, and mortality risk, therefore should be included in the follow-up.

Effects of high intensity physical training in patients with Chronic Obstructive Pulmonary disease in a Pulmonary Rehabilitation Program / Efeitos do treino físico de alta intensidade em doentes com doença pulmonar obstrutiva crónica num Programa de Reabilitação Pulmonar

Objective: To evaluate the effect of high intensity physical training on a supervised Pulmonary Rehabilitation Program (PRP) in patients with Chronic Obstructive Pulmonary Disease (COPD). Methods: Interventional study with 30 patients with COPD, randomly divided into 2 groups: Control Group (CG) submitted to physical training of a traditional PRP and Experimental Group (EG) with bodybuilders with duration of 30 sessions in days alternates. All submitted to pre and post-intervention evaluation with the following variables: (I) pulse oximetry (SpO2); (II) 6 'walk test (6MWT); (III) Saint George's Quality of Life Questionnaire (SGRQ); (IV) DPOC assessment test (CAT); (V) cardiopulmonary exercise test; and (VI) 1 maximal repetition test (MRI). Results: Pre and post-intervention values were compared and the GE group presented a significant difference in the following parameters: increase 30.53 meters in the distance covered (p 0.021) improvement in all scores: CAT score for 12 points (p 0.001), Score Saint George from 27 to 19 points (p 0.005), and in the improvement of the maximum physical capacity with increase 14 to 18 of (VO2 (%) (p 0.007) and 0,87 to 1,12 VO2 (L/min) (p 0.01) Conclusions: There was a significant improvement in exercise capacity and quality of life of the GE group, suggesting that high intensity physical training is the most efficient alternative in the treatment of patients with moderate COPD will be severe.

Reproducibility of strength performance and strength-endurance profiles: A test-retest study.

The present study was designed to evaluate the test-retest consistency of repetition maximum tests at standardized relative loads and determine the robustness of strength-endurance profiles across test-retest trials. Twenty-four resistance-trained males and females (age, 27.4 ± 4.0 y; body mass, 77.2 ± 12.6 kg; relative bench press one-repetition maximum [1-RM], 1.19 ± 0.23 kg•kg-1) were assessed for their 1-RM in the free-weight bench press. After 48 to 72 hours, they were tested for the maximum number of achievable repetitions at 90%, 80% and 70% of their 1-RM. A retest was completed for all assessments one week later. Gathered data were used to model the relationship between relative load and repetitions to failure with respect to individual trends using Bayesian multilevel modeling and applying four recently proposed model types. The maximum number of repetitions showed slightly better reliability at lower relative loads (ICC at 70% 1-RM = 0.86, 90% highest density interval: [0.71, 0.93]) compared to higher relative loads (ICC at 90% 1-RM = 0.65 [0.39, 0.83]), whereas the absolute agreement was slightly better at higher loads (SEM at 90% 1-RM = 0.7 repetitions [0.5, 0.9]; SEM at 70% 1-RM = 1.1 repetitions [0.8, 1.4]). The linear regression model and the 2-parameters exponential regression model revealed the most robust parameter estimates across test-retest trials. Results testify to good reproducibility of repetition maximum tests at standardized relative loads obtained over short periods of time. A complementary free-to-use web application was developed to help practitioners calculate strength-endurance profiles and build individual repetition maximum tables based on robust statistical models.

Effects of Aging on Cardiac Autonomic Response during Resistance Exercise at Critical Load

Background: Critical load (CL) indicates the transition from moderate dynamic exercise to intense exercise and can be useful as a parameter of exercise intolerance during resistance exercise. In this sense, this study aimed to assess and contrast the cardiac autonomic response by heart rate variability during resistance exercise at CL in elderly and young individuals. Methods: Twenty apparently healthy active men, were allocated into young group (n=10) and elderly group (n=10), who underwent: 1) one repetition maximum (1RM) test on the Leg Press at 45º; 2) constant load exercise tests (70%, 80% and 90% of 1RM and intermediate load) in order to calculate the CL; and 3) CL assessment with record of heart rate (HR) and R-R intervals (R-Ri) to heart rate variability assessment. Results: During CL, the elderly presented lower value of mean HR in relation to young group (p<0.05), and mean R-Ri, RMSSD and SD1 were higher in elderly compared to young (p<0.05). In addition, delta (exercise minus rest) mean HR, STDRR, RMSSD, RRtri, TINN, SD1, SD2 and correlation dimension were lower in elderly compared to young (p<0.05). Conclusion: Elderly presented lower response to vagal withdrawal and less complexity compared to the young people during resistance exercise at CL.

Effect of Exercise Training Programs on Physical Fitness Domains in Military Personnel: A Systematic Review and Meta-Analysis

Physical training is important to prepare soldiers for the intense occupational demands in the military. However, current physical training may not address all fitness domains crucial for optimizing physical readiness and reducing musculoskeletal injury. The effects of nontraditional military physical training on fitness domains have been inconsistently reported, which limits the design of the ideal training program for performance optimization and injury prevention in the military. The aim of this systematic review was to identify the effects of exercise training on various fitness domains (i.e., aerobic fitness, flexibility, muscular endurance, muscular power, muscular strength, and occupationally specific physical performance) that contribute to occupational performance and musculoskeletal injury risk in military personnel. An extensive literature search was conducted in January 2021 and was subsequently updated in July 2021 and December 2021. Included studies consisted of comparative groups of healthy military personnel performing traditional and nontraditional military physical training with at least one assessment representative of a fitness domain. Study appraisal was conducted using the PEDro scale. Meta-analysis was conducted via forest plots, standard mean difference (SMD, effect size), and intertrial heterogeneity (I2). From a total of 7,350 records, 15 studies were identified as eligible for inclusion in this review, with a total of 1,613 participants. The average study quality via the PEDro score was good (5.3/10; range 4/10 to 6/10). Nontraditional military physical training resulted in greater posttraining values for muscular endurance (SMD = 0.46; P = .004; I2 = 68%), power (SMD = 1.57; P < .0001; I2 = 90%), strength via repetition maximum testing (SMD = 1.95; P < .00001; I2 = 91%), and occupationally specific physical performance (SMD = 0.54; P = .007; I2 = 66%) compared to the traditional group. There was no significant difference for aerobic fitness (SMD = -0.31; P = .23; I2 = 86%), flexibility (SMD = 0.58; P = .16; I2 = 76%), and muscular strength via maximal voluntary contraction (SMD = 0.18; P = .28; I2 = 66%) between training groups. The current systematic review identified that nontraditional military physical training had a greater posttraining effect on muscular endurance, power, strength measured via repetition maximum, and occupationally specific physical performance compared to traditional military physical training. Overall, these findings suggest that nontraditional military physical training may be beneficial in optimizing occupational performance while potentially reducing musculoskeletal injury risk.

EFEITO DO TREINO DE FORÇA NA HIPERTROFIA MUSCULAR EM IDOSOS SAUDÁVEIS: UMA REVISÃO SISTEMÁTICA

OBJECTIVE: To systematically summarize the literature considering studies that address strength training and its effects on muscle hypertrophy in healthy older people. METHODS: The search was developed on the PubMed platform considering the PICOS strategy. The search date of the selected studies included the last 5 years (01.01.2017 to 07.21.2021). Studies in any language were considered. As eligibility criteria, the studies were required to contain: healthy older people; interventions with strength exercises; outcomes with hypertrophy measures (MRI, ultrasound, etc). RESULTS: In total, 14 studies were included, totaling 470 older individuals (296 participants in the experimental group and 174 participants in the control group), aged between 60 and 80 years. The strength training interventions took place over between 4 and 30 weeks, with sessions from 1 to 7 times a week. Tests of balance, measurement of muscle temperature, capacity and functional performance, and strength tests were also carried out, with the most common being the 1 repetition maximum test (1RM). For the hypertrophy measurements, dual energy X-ray (DXA), ultrasound, bioelectrical impedance, and computed tomography were used. The analyzed studies showed a significant increase in muscle volume in the intervention groups when compared to control groups (follow-up or comparison). However, studies with comparison groups (another strength training strategy or protocol) also showed increases in muscle volume, with no differences between groups. CONCLUSION: Strength training is effective in promoting improvements in muscle volume in older adults.

Physical Fitness-Not Physical Activity Levels-Influence Quality of Life in Anorexia Nervosa.

Background: Incorporating physical activity (PA) has been a challenge for health care professionals working with anorexia nervosa (AN) patients. This has contributed to partial physical fitness (PFit) recovery that persists after weight restoration. Objective: This cross-sectional study aimed to examine the relationships between PA, sedentary behaviors, PFit, and quality of life (QoL) in a group of adolescents after hospitalization. Methods: QoL, PA, and sedentary behaviors were measured using the Health-Questionnaire Short-Form 36 (SF-36) and accelerometers, while PFit was assessed through cardiorespiratory fitness, body composition (anthropometry), and strength (six repetition maximum) tests in a total of 63 patients. Results: Light-PA (LPA), moderate-PA (MPA), moderate-to-vigorous-PA (MVPA), and relative sedentary time (%ST) did not meet the recommendations (p < 0.001). Only 22% of the patients met MVPA criteria, and ~82% exceeded %ST. SF-36 scores were lower than normative values except the physical component scale. Absolute cardiorespiratory fitness was reduced (p < 0.001) in 84% of the patients, and was positively associated to body weight, body mass index (BMI), circumferences, and muscle areas. Additional positive significant relationships were found between QoL, muscular strength, and body composition, and negative associations between vigorous-to-very vigorous PA and BMI, skinfolds, and percent body fat. Regression analyses revealed lower body strength as an explanatory factor for improved QoL (OR 1.03, 95%CI 1.00–1.07). Conclusions: PFit and QoL scores are poor after hospitalization. LPA, MPA, and MVPA do not meet recommendations. PFit management—with emphasis on improving muscular fitness—may be a valuable strategy for QoL improvement in AN after hospitalization.

Kinetics and Kinematics of the Free-Weight Back Squat and Loaded Jump Squat.

Thompson, SW, Lake, JP, Rogerson, D, Ruddock, A, and Barnes, A. Kinetics and kinematics of the free-weight back squat and loaded jump squat. J Strength Cond Res 37(1): 1-8, 2023-The aim of this study was to compare kinetics and kinematics of 2 lower-body free-weight exercises, calculated from concentric and propulsion subphases, across multiple loads. Sixteen strength-trained men performed back squat 1 repetition maximum (1RM) tests (visit 1), followed by 2 incremental back squat and jump squat protocols (visit 2) (loads = 0% and 30-60%, back squat 1RM). Concentric phase and propulsion phase force-time-displacement characteristics were derived from force plate data and compared using analysis of variance and Hedges' g effect sizes. Intrasession reliability was calculated using intraclass correlation coefficient (ICC) and coefficient of variation (CV). All dependent variables met acceptable reliability (ICC >0.7; CV < 10%). Statistically significant 3-way interactions (load × phase × exercise) and 2-way main effects (phase × exercise) were observed for mean force, velocity (30-60% 1RM), power, work, displacement, and duration (0%, 30-50% 1RM) ( p < 0.05). A significant 2-way interaction (load × exercise) was observed for impulse ( p < 0.001). Jump squat velocity ( g = 0.94-3.80), impulse ( g = 1.98-3.21), power ( g = 0.84-2.93), and work ( g = 1.09-3.56) were significantly larger across concentric and propulsion phases, as well as mean propulsion force ( g = 0.30-1.06) performed over all loads ( p < 0.001). No statistically significant differences were observed for mean concentric force. Statistically longer durations ( g = 0.38-1.54) and larger displacements ( g = 2.03-4.40) were evident for all loads and both subphases ( p < 0.05). Ballistic, lower-body exercise produces greater kinetic and kinematic outputs than nonballistic equivalents, irrespective of phase determination. Practitioners should therefore use ballistic methods when prescribing or testing lower-body exercises to maximize athlete's force-time-displacement characteristics.

Different types of mechanical vibration application on EMG response and strength performance

Aim: The present study aimed to compare the strength performance and the neuromuscular activity during one maximum repetition test (1RM), and the maximum voluntary isometric contractions (MVIC) performed with whole-body vibration (WBV), local vibration (LV), and no vibration (NV). Methods: The sample consisted of 15 males, experienced in strength training for at least 6 months, which performed all strength tests in the barbell curl exercise across randomized trials on the following conditions: NV, WBV, and LV. During all tests, the normalized root means square values of the electromyographic signals (EMGRMS) of the biceps brachii and brachioradialis were recorded and compared between the conditions. The one-way ANOVAs with repeated measures were used to compare the results of 1RM and MVIC tests and the normalized EMGRMS between the conditions. When necessary, a post hoc Scott-Knott test was used to identify the differences reported in the ANOVAs. The significance level adopted was α < 0.05. Results: The EMGRMS response of the biceps brachii and brachioradialis muscles during the 1RM and MVIC tests presented significantly higher values at LV compared to WBV, and NV (p < 0.001). The 1RM tests, and the MVIC results were similar between conditions (p = 0.9803; p = 0.061, respectively). Conclusion: These results indicate that the application of MV was not sufficient to increase strength performance.

Nine-Axis Sensor for Athlete Physical Training Load Characteristics.

In order to understand the characteristic data of athletes' training load, a method based on nine-axis sensor was proposed. Twenty-seven male college athletes were tested twice with a time interval of more than 48 hours. In part 1, participants take the 1 Repetition Maximum (1RM) test. The results show that maximum strength is one of the basic factors to develop the output power of athletes. In the process of skeletal muscle contraction, the curve of speed, force, and power is closely related. When the external load is 10%∼70%, the average power increases with the increase in the average force, it increases with the decrease in the average speed, and at 70%1RM, the average power reaches the peak and then decreases at an inflection point. It is proved that the accurate weight ratio of strength training is the basis of winning athletes, the focus of high level physical coach, and the premise of scientific sports training.

Impact of aerobic versus resistive training on functional capacity in acute myeloid leukemia survivors: a comparative study

Background. Cancer-related fatigue is a persistent symptom in acute myeloid leukemia survivors, with associated decreased functional capacity, which further deteriorates their quality of life. The current study aimed to compare between the impact of aerobic training and resistive training on functional capacity in acute myeloid leukemia (AML) survivors. Fifty nine patients with AML from both sexes aged between 35 and 45 years,were selected from hematology department in (BLINDED FOR PEER REVIEW), where the study was conducted. Patients were randomly assigned into two groups; Group (A) underwent aerobic training in the form of cycling within 50-60% of maximum heart rate. Group (B) underwent resistive training conducted in the form of a series of exercises using free weights, and dumbbells. Sessions were carried out three times per week, for a total of eight weeks period. Six minute walk test (6MWT), 10 repetitions maximum test (10 RM). Ventilatory functions test, fatigue severity assessment (FAS) and quality of life (QoL) scales were measured in both groups before and after the study period. Results. Significant improvement in 6MWT, maximum oxygen consumption (VO2 max) and vital capacity in group (A), significant improvement in fatigue and QoL in both groups and significant improvement in 10 RM test in group (B). Conclusion. Both aerobic and resistive training significantly improved functional capacity in acute myeloid leukemia survivors with a more significant improvement due to aerobic training.

Impact of Exercise Modalities on Peripheral and Central Components of Cardiorespiratory Capacity in Heart Transplantation Patients: A Systematic Review and Meta-Analysis.

Background and Objectives: To analyze the effects of aerobic, resistance, and combined training on peripheral and central components related to cardiorespiratory capacity after HTx. Materials and Methods: No time restriction was applied for study inclusion. MEDLINE/PubMed; EMBASE, CENTRAL, and PEDro databases were investigated. Studies reporting heart transplanted patients older than 19 years following aerobic, resistance, and combined training according. The outcomes included: V′O2 peak, VE/V’CO2 slope, heart rate (HR peak), systolic and diastolic blood pressure (SBP and DBP peak), maximum repetition test(1RM), sit-to-stand test, and flow-mediated dilation (FMD). The studies were selected by consensus. Four hundred ninety-two studies initially met the selection criteria. Cochrane handbook was used for abstracting data and assessing data quality and validity. Independent extraction by two observers was applied. Results: Isolated aerobic training leads to a greater increase in V′O2 peak than combined training compared to the control group (p < 0.001, I2 = 0%). However, no significant differences were found in the subgroup comparison (p = 0.19, I2 = 42.1%). HR peak increased similarly after aerobic and combined training. High-intensity interval training (HIIT) was better than moderate continuous intensity to increase the V′O2 after long term in HTx. Still, there is scarce evidence of HIIT on muscle strength and FMD. No change on VE/V’CO2 slope, FMD, and SBP, DBP peak. 1RM and the sit-to-stand test increased after resistance training (p < 0.001, I2 = 70%) and CT (p < 0.001, I2 = 0%) when compared to control. Conclusions: Aerobic and combined training effectively improve VO2 peak and muscle strength, respectively. HIIT seems the better choice for cardiorespiratory capacity improvements. More studies are needed to examine the impact of training modalities on VE/V’CO2 slope and FMD.

Residual Impact of Concurrent, Resistance, and High-Intensity Interval Training on Fasting Measures of Glucose Metabolism in Women With Insulin Resistance.

We sought to assess the residual effects (post 72-h training cessation) on fasting plasma glucose (FPG) and fasting insulin (FI) after 12-weeks of high-intensity interval training (HIIT), resistance training (RT), or concurrent training (CT) in women with insulin resistance (IR). We also aimed to determine the training-induced, post-training residual impact of CT. A total of adult 45 women (age 38.5±9.2years) were included in the final analysis and were assigned to a control (CG; n=13, BMI 28.3±3.6kg/m2), HIIT [n=14, BMI 28.6±3.6kg/m2, three sessions/wk., 80–100% of the maximum heart rate (HRmax)], RT [n=8, BMI 29.4±5.5kg/m2, two sessions/wk., 8–10 points of the modified Borg, corresponding to 20 to 50% range of one maximum repetition test (1RM)], or CT group (n=10, BMI 29.1±3.0kg/m2, three sessions/wk., 80–100% of HRmax, and 8–10 Borg, or 20 to 50% range of 1RM, to each HIIT and RT compounds), with the latter including both HIIT and RT regimens. Training interventions lasted 12-weeks. The main outcomes were FPG and FI measured at pre- and 24-h and 72-h post-training (FPG24h, FI24h, and FPG72h, FI72h, respectively). Secondary endpoints were body composition/anthropometry and the adiposity markers waist circumference (WC) and tricípital skinfold (TSF). The residual effects 72-h post-training [delta (∆)] were significantly poorer (all p<0.01) in the CT group (∆FPG72h+6.6mg/dl, η2: 0.76) than in the HIIT (∆FPG72h+1.2mg/dl, η2: 0.07) and RT (∆FPG72h+1.0mg/dl, η2: 0.05) groups. These findings reveal that HIIT reduces FPG and RT reduces FI 24-h post-training; both exercise interventions alone have remarkably better residual effects on FPG and FI (post-72h) than CT in women with insulin resistance.

Força muscular e resistência aeróbia: existem diferenças de desempenho físico durante as fases de dois ciclos menstruais?

Introdução: O ciclo menstrual tem sido apontado como um possível fator de interferência no treinamento físico, porém a relação entre suas diferentes fases e o desempenho físico tem sido alvo recente de investigação. Objetivo: Verificar o desempenho físico nas capacidades biomotoras de resistência aeróbia e força muscular durante as fases do ciclo menstrual. Métodos: Durante dois ciclos menstruais, 12 mulheres saudáveis, ativas e usuárias de contraceptivos orais foram submetidas a um protocolo de treinamento e foram avaliadas quanto ao desempenho físico em cada fase de cada ciclo menstrual por meio dos testes: Yo Yo Test 1 e teste de uma repetição máxima (1RM) para os exercícios: cadeira extensora, supino reto, cadeira flexora e remada. Resultados: Houve redução do desempenho no teste de resistência na fase folicular para ambos os ciclos menstruais avaliados. Já o comportamento da força muscular apresentou-se significativamente maior (p &lt; 0,05) no segundo ciclo para os exercícios supino reto e cadeira flexora. Conclusão: O desempenho na capacidade de resistência em mulheres ativas, quando avaliado em dois ciclos menstruais, é menor na fase folicular, e que o desempenho de força muscular não foi influenciado pelas fases do ciclo menstrual.

One Repetition Maximum Test-Retest Reliability and Safety Using Keiser Pneumatic Resistance Training Machines With Older Women.

Infante, MA, Harrell, GM, Strand, KL, Parrino, RL, and Signorile, JF. One repetition maximum test-retest reliability and safety using Keiser pneumatic resistance training machines with older women. J Strength Cond Res 35(12): 3513-3517, 2021-Chest press (CP) and leg press (LP) are the most common exercises used to assess strength in older persons; therefore, the reliability of these tests is critical to clinicians and researchers. Because women comprise the highest proportion of the older population, this study examined the test-retest reliability of Keiser A420 pneumatic machines during CP and LP 1 repetition maximum (1RM) testing in 23 older women on 2 separate occasions, trial 1 (T1) and trial 2 (T2), at least 72 hours apart. Significance was set at <0.05. CP1RM and LP1RM showed excellent test-retest reliability (intraclass correlation coefficient = 0.974, 0.972, respectively, p < 0.001) and low coefficients of variation (CP1RM = 5.28%; LP1RM = 6.32%). Standard error of measurement for CP1RM (0.97 kg) was lower than that of LP1RM (6.36 kg). The minimal detectable change (MDC) for the CP1RM and LP1RM was 2.69 and 17.63 kg, respectively. Bland-Altman plots revealed only 1 point outside of the 95% CI for comparison of T1 and T2 for either exercise, there was little systematic error across average values, both lines of equality fell within the limits of agreement (LOA), and the bias between T1 and T2 for both exercises was below 5% of the average 1RM. By contrast, the LOA for CP1RM and LP1RM are somewhat wide because they both exceeded their computed MDC values. Given the excellent test-retest reliability of the Keiser A420 pneumatic CP and LP machines with older women, clinicians and researchers can confidently and safely use these machines for 1RM testing after proper familiarization.

ISCHEMIC PRECONDITIONING IMPROVES AUTONOMIC MODULATION AFTER SESSION OF RESISTANCE EXERCISE

The aim of this study was to investigate the acute effect of ischemic preconditioning (IPC) in a session of resistance exercise (RE) for upper and lower limbs on the heart rate variability (HRV) in normotensive and trained men. sixteen normotensive and trained men visit the laboratory in five sessions in non-consecutive days. The first two sessions subjects performed one repetition maximum (RM) test and retest, and the next three visits they performed the experimental protocols: a) RE (CON), b) IPC+RE (IPC), c) SHAM+RE (SHAM). RE were performed in 3 sets at 80% 1RM until concentric failure. IPC consisted of 4x5-mins of vascular occlusion at 220 mmHg alternating with 5-min of reperfusion. SHAM protocol followed the same IPC method with 20mmHg vascular occlusion. A significant decrease in LF­nu and RMSSDms (p=0.001) was found from baseline for IPC, SHAM, and CON. A significant increase in HFnu and LF/HF (p=0.001) was found from baseline for IPC, SHAM, and CON. A significant decrease in LF­nu and LF/HF was observed from 60-min post for IPC vs. SHAM and IPC vs. CON (p&lt;0.05). A significant increase in HFnu was observed from 60-min post for IPC vs. SHAM and IPC vs. CON (p&lt;0.05). A significant increase in RMSSDms was found from post-60 for IPC vs. SHAM (p &lt; 0.05). RE followed IPC shows significantly improvements in the autonomic cardiac modulation, accelerating the autonomic recovery after the RE session, by increasing the vagal activity and reducing the sympathetic activation when compared to RE and SHAM protocols.

Acute Effects of Intermittent Foot Cooling on 1 RM Leg Press Strength in Resistance-Trained Men: A Pilot Study.

Inter-set peripheral cooling can improve high-intensity resistance exercise performance. However, whether foot cooling (FC) would increase 1 repetition maximum (RM) lower-limb strength is unclear. This study investigated the effect of intermittent FC on 1 RM leg press strength. Ten recreational male lifters performed three attempts of 1 RM leg press with FC or non-cooling (NC) in a repeated-measures crossover design separated by 5 days. FC was applied by foot immersion in 10 °C water for 2.5 min before each attempt. During the 1 RM test, various physiological measures were recorded. The results showed that FC elicited higher 1 RM leg press strength (Δ [95% CI]; Cohen’s d effect size [ES]; 13.6 [7.6–19.5] kg; ES = 1.631) and electromyography values in vastus lateralis (57.7 [8.1–107.4] μV; ES = 0.831) and gastrocnemius (15.1 [−3.1–33.2] μV; ES = 0.593) than in NC. Higher arousal levels (felt arousal scale) were found in FC (0.6 [0.1–1.2]; ES = 0.457) than in NC. In conclusion, the preliminary findings, although limited, suggest intermittent FC has a potential ergogenic role for recreational athletes to enhance maximal lower-limb strength and may partly benefit strength-based competition events.

The Relationship Between High-intensity Functional Training Performance And Laboratory-based Measurements Of Fitness

To date, research has examined the physiological determinants of performance in standardized High-Intensity Functional Training (HIFT) workouts but not without the influence of HIFT familiarity. PURPOSE: To examine the predictive value of aerobic fitness, body composition, and total body strength on performance of two standardized HIFT workouts in HIFT-naïve participants. METHODS: Twenty-two recreationally trained individuals (males = 13, females = 9) underwent assessments of peak oxygen consumption (VO2 peak), ventilatory thresholds, body composition, and one repetition maximum tests for the back squat, deadlift, and overhead press in which the sum equaled the total strength. Participants also performed two standardized HIFT workouts: a scaled version of the 19.1 (as many sets of 19 wall balls followed by 19 calories on rower within 15 minutes) and a modified Fran (sets of 21, 15, and 9 repetitions of thrusters and burpees) to determine scores based on total repetitions completed and time-to-completion, respectively. Simple Pearson’s r correlations were used to determine the relationships between HIFT performance variables (19.1 and modified Fran) and the independent variables. A forward stepwise multiple linear regression analysis was performed and significant variables that survived the regression analysis were used to create a predictive model of HIFT performance. RESULTS: Absolute VO2 peak was a significant predictor of 19.1 performance, explaining 39% of its variance (adjusted R2 = 0.39, p = 0.002). For modified Fran, total strength was a significant predictor and explained 33% of the variance in performance (adjusted R2 = 0.33, p = 0.005). CONCLUSION: These results suggest, without any influence of HIFT familiarity or experience, that performance in these two HIFT workouts could be predicted by distinct laboratory-based measurements of fitness.