Low-Load Resistance Training Performed to Muscle Failure or Near Muscle Failure Does Not Promote Additional Gains on Muscle Strength, Hypertrophy, and Functional Performance of Older Adults.

ABSTRACT: Bergamasco, JGA, Gomes da Silva, D, Bittencourt, DF, Martins de Oliveira, R, Júnior, JCB, Caruso, FC, Godoi, D, Borghi-Silva, A, and Libardi, CA. Low-load resistance training performed to muscle failure or near muscle failure does not promote additional gains on muscle strength, hypertrophy, and functional performance of older adults. J Strength Cond Res 36(5): 1209-1215, 2022-The aim of the present study was to compare the effects of low-load resistance training (RT) protocols performed to failure (FAI), to voluntary interruption (VOL), and with a fixed low repetitions (FIX) on muscle strength, hypertrophy, and functional performance in older adults. Forty-one subjects (60-77 years) were randomized into one of the RT protocols (FAI, VOL, or FIX) and completed 12 weeks of RT at 40% of 1 repetition maximum (1RM), twice a week. The assessments included 1RM test, muscle cross-sectional area (CSA), rate of torque development (RTD), and functional performance (chair stand [CS], habitual gait speed [HGS], maximal gait speed [MGS], and timed up-and-go [TUG]). All protocols significantly increased 1RM values from Pre (FAI: 318.3 ± 116.3 kg; VOL: 342.9 ± 93.7 kg; FIX: 328.0 ± 107.2 kg) to Post (FAI: 393.0 ± 143.1 kg, 23.5%; VOL: 423.0 ± 114.5 kg, 23.3%; FIX: 397.8 ± 94.6 kg, 21.3%; p < 0.0001 for all groups). Regarding CS, all protocols showed significant improvements from Pre (FAI: 11.5 ± 2.4 seconds; VOL: 12.1 ± 2.5 seconds; FIX: 11.3 ± 1.1 seconds) to Post (FAI: 10.5 ± 1.1 seconds, -8.5%, p = 0.001; VOL: 10.3 ± 1.5 seconds, -15.1%, p = 0.001; FIX: 11.0 ± 1.1, -3.2%, p = 0.001). Habitual gait speed values increased significantly from Pre (FAI: 1.3 ± 0.2 m·s-1; VOL: 1.3 ± 0.1 m·s-1; FIX: 1.3 ± 0.1 m·s-1) to Post (FAI: 1.4 ± 0.2 m·s-1, 2.5%, p = 0.03; VOL: 1.4 ± 0.2 m·s-1, 5.2%, p = 0.036; FIX: 1.4 ± 0.1 m·s-1, 5.7%, p = 0.03). No significant differences between protocols were found (p > 0.05). In addition, there were no significant changes in CSA, RTD, MGS, and TUG for any protocols (p > 0.05). In conclusion, low-load RT performed without muscle failure promotes significant improvements in muscle strength and some parameters of functional performance in older adults.

The effect of passive mobilization associated with blood flow restriction and combined with electrical stimulation on cardiorespiratory safety, neuromuscular adaptations, physical function, and quality of life in comatose patients in an ICU: a randomized controlled clinical trial.

BACKGROUND: Intensive care unit-acquired atrophy and weakness are associated with high mortality, a reduction in physical function, and quality of life. Passive mobilization (PM) and neuromuscular electrical stimulation were applied in comatose patients; however, evidence is inconclusive regarding atrophy and weakness prevention. Blood flow restriction (BFR) associated with PM (BFRp) or with electrical stimulation (BFRpE) was able to reduce atrophy and increase muscle mass in spinal cord-injured patients, respectively. Bulky venous return occurs after releasing BFR, which can cause unknown repercussions on the cardiovascular system. Hence, the aim of this study was to investigate the effect of BFRp and BFRpE on cardiovascular safety and applicability, neuromuscular adaptations, physical function, and quality of life in comatose patients in intensive care units (ICUs). METHODS: Thirty-nine patients will be assessed at baseline (T0-18 h of coma) and randomly assigned to the PM (control group), BFRp, or BFRpE groups. The training protocol will be applied in both legs alternately, twice a day with a 4-h interval until coma awake, death, or ICU discharge. Cardiovascular safety and applicability will be evaluated at the first training session (T1). At T0 and 12 h after the last session (T2), muscle thickness and quality will be assessed. Global muscle strength and physical function will be assessed 12 h after T2 and ICU and hospital discharge for those who wake up from coma. Six and 12 months after hospital discharge, physical function and quality of life will be re-assessed. DISCUSSION: In view of applicability, the data will be used to inform the design and sample size of a prospective trial to clarify the effect of BFRpE on preventing muscle atrophy and weakness and to exert the greatest beneficial effects on physical function and quality of life compared to BFRp in comatose patients in the ICU. TRIAL REGISTRATION: Universal Trial Number (UTN) Registry UTN U1111-1241-4344. Retrospectively registered on 2 October 2019. Brazilian Clinical Trials Registry (ReBec) RBR-2qpyxf . Retrospectively registered on 21 January 2020, http://ensaiosclinicos.gov.br/rg/RBR-2qpyxf/.

Circulatory and ventilatory power in diabetic patients: Secondary analysis of a randomized controlled trial.

BACKGROUND: Circulatory (CP) and ventilatory power (VP) have been used to improve the prognostic accuracy of cardiopulmonary exercise tests in cardiovascular disease, such as coronary artery disease. However, the effects of combined resistance and aerobic exercise program on VP and CP, especially in type 2 diabetes patients, have not been adequately investigated. Thus, this new parameter can be useful to prescribe exercise programs more assertive for this population. The present study aimed to assess the effect of 3 months of combined resistance and aerobic exercise training (CET) on CP and VP in patients with type 2 diabetes. METHODS: A randomized controlled trial was conducted involving 48 diabetic patients with an average age of 52.4 (±8.01) years old. The subjects were randomized into two groups: sedentary (SG, n = 15) and the CET group (n = 19). Cardiopulmonary exercise testing (symptom-limited incremental) was performed on a cycle ergometer, and the following parameters were measured: relative VO2 , VE /VCO2 slope, linear relationship between oxygen uptake and minute ventilation, and VCO2 . CET was performed with 30-min aerobic and 30-min resistance exercises three times a week for 12 weeks. RESULTS: Significant (p < .05) and clinical (d ≥ .80) differences were observed that favoured CET compared with SG for the following variables: heart rate, workload, VO2 relative peak, circulatory power peak, and VCO2 peak. Although no statistical difference was observed for ventilatory power, there was a clinical difference (p > .05 and d ≥ 0.80) that favoured CET. CONCLUSION: Three months of combined exercise training improved VP and CP indices in patients with type 2 diabetes when compared with a sedentary group.

Hemodynamic and metabolic response during dynamic and resistance exercise in different intensities: a cross-sectional study on implications of intensity on safety and symptoms in patients with coronary disease.

Resistance (RE) and aerobic exercise (AE) can promote hemodynamic, physiologic and clinical modifications in coronary artery disease (CAD) patients. The aim of the study is to assess key physiologic and clinical responses during RE at 30% and 60% of 1-RM on a 45° leg press and to compare responses during AE. We evaluated fifteen male subjects with coronary artery disease (60.8±4.7 years) that performed the following tests: (1) incremental AE test on cycle ergometer; (2) 1-RM test on a leg press at 45°; (3) and RE at 30% and 60% of 1-RM for 24 repetitions. Peak cardiac output (CO), heart rate (HR), oxygen consumption (VO2), carbon dioxide production (VCO2) and the minute ventilation (VE, L/min)/VCO2 ration were measured. We found that both AE and RE at 60% of aerobic and resistance capacity elicited similar hemodynamic and ventilatory responses (p>0.05). However, RE at 30% 1-RM showed more attenuated responses of VO2, VE/VCO2, HR and CO when compared with 60% of aerobic and resistance capacity. Interestingly, the number, percentage and the severity of arrhythmias were higher at 60% 1-RM (P<0.05). Our data suggest that high repetition sets of RE at 60% 1-RM appears to result in hemodynamic, ventilatory, and metabolic changes equivalent to those observed during AE at a comparable intensity.

Potential Effects on Cardiorespiratory and Metabolic Status After a Concurrent Strength and Endurance Training Program in Diabetes Patients - a Randomized Controlled Trial.

BACKGROUND: Concurrent aerobic and resistance training (CART) programs have been widely recommended as an important strategy to improve physiologic and functional performance in patients with chronic diseases. However, the impact of a personalized CART program in patients with type 2 diabetes (T2D) requires investigation. Therefore, the primary aim of the current study is to investigate the impact of CART programs on metabolic profile, glycemic control, and exercise capacity in patients with diabetes. METHODS: We evaluated 41 subjects with T2D (15 females and 19 males, 50.8 ± 7 years); subjects were randomized into two groups; sedentary (SG) and CART (CART-G). CART was performed over 1.10-h sessions (30-min aerobic and 30-min resistance exercises) three times/week for 12 weeks. Body composition, biochemical analyses, peripheral muscular strength, and cardiopulmonary exercise testing were primary measurements. RESULTS: The glycated hemoglobin HbA1c (65.4 ± 17.9 to 55.9 ± 12.7 mmol/mol), cholesterol (198.38.1 ± 50.3 to 186.8 ± 35.1 mg/dl), and homeostasis model assessment insulin resistance (HOMA-IR) (6.4 ± 6.8 to 5.0 ± 1.4) decreased in the CART-G compared to the SG. Although body weight did not significantly change after training, skinfold measurement indicated decreased body fat in the CART-G only. CART significantly enhanced muscle strength compared to the SG (p < 0.05). CART was also associated with significant increase in peak oxygen uptake and maximal workload compared to the SG (p < 0.05). CONCLUSIONS: These data support CART as an important strategy in the treatment of patients with T2D, producing both physiologic and functional improvements. TRIAL REGISTRATION: Ensaiosclinicos.gov.br, RBR492q8z.