Resistance Training With Partial Blood Flow Restriction in a 99-Year-Old Individual: A Case Report

In aging populations for which the use of high loads is contraindicated, low load resistance training associated with blood flow restriction (RT-BFR) is an alternative strategy to induce muscle mass gains. This study investigates the effects of RT-BFR on muscle mass, muscle function, and quality of life of a 99-year-old patient with knee osteoarthritis and advanced muscle mass deterioration. Training protocol consisted of 24 sessions of a unilateral free-weight knee extension exercise associated with partial blood flow restriction through a manometer cuff set at 50% of complete vascular occlusion pressure. We evaluated: cross-sectional area (CSA) and thickness (MT) of the vastus lateralis muscle by ultrasound; function through the Timed Up and Go (TUG) test; and quality of life (QoL) by the WHOQOL-bref, WHOQOL-OLD and WOMAC questionnaires. All tests were performed prior to the training period (Pre) and after the 12th (Mid) and 24th (Post) sessions. Changes were considered significant if higher than 2 times the measurement's coefficient of variation (CV). After 24 sessions, there was an increase of 12% in CSA and 8% in MT. Questionnaires scores and TUG values worsened from Pre to Mid and returned in Post. We consider RT-BFR a viable and effective strategy to promote muscle mass gains in nonagenarians and delay the decline in functionality and QoL associated with aging

Concurrent training effects on heart rate variability, blood pressure and fitness of middle-aged men and women

The concurrent training led to beneficial effects on aerobic fitness and muscle strength. However, its effects on blood pressure (BP) and autonomic control marks are little studied. This study aimed to evaluate the concurrent training effects on BP, autonomic control, aerobic fi tness and muscle strength of middle-aged men and women. Thirty-two volunteers (51.4 ± 4.2 years, systolic BP 115 ± 12 mmHg and diastolic BP 78 ± 8 mmHg) were divided into 4 groups of 8 volunteers: male concurrent training (MCT), female concurrent training (FCT), male sedentary control (MSC) and female sedentary control (FSC) groups. A minimum absence of menstruation for 12-months was required. Concurrent training, six resistance exercise for whole body followed by 30 min of jogging and/or running at 55%–85% of VO2peak, was performed three times a week. The main assessments were rest BP and cardiovascular autonomic markers evaluated through heart rate variability (iRR, LF, HF, LF/HF, RMSSD, pNN50, SD1 and SD2), aerobic fitness measured by cardiorespiratory test (VO2peak) and muscle strength by one repetition maximum (1-RM - arm curl, bench press and leg press). The concurrent training did not change any cardiovascular variables. Regarding fitness the MCT and FCT groups demonstrated signifi cant improvement in VO2peak (13.12% e 8.51%, respectively). Muscle strengthimproved significantly in the MCT group in all three exercises (arm curl: 26.53%; bench press: 25.04%; leg press: 65.37%), while FCT in just two exercises (arm curl: 12.79%; bench press: 17.25%). Although concurrent training appears to be a good alternative for inducing improvements in various physical fitnessvariables in male, its can induce concurrence in leg strength of female. Concurrent training is not an effective strategy to improve BP and autonomic nervous system

The Association Between Muscle Deoxygenation and Muscle Hypertrophy to Blood Flow Restricted Training Performed at High and Low Loads

The metabolic stress induced by blood flow restriction (BFR) during resistance training (RT) might maximize muscle growth. However, it is currently unknown whether metabolic stress are associated with muscle hypertrophy after RT protocols with high- or low load. Therefore, the aim of the study was to compare the effect of high load RT (HL-RT), high load BFR (HL-BFR), and low load BFR (LL-BFR) on deoxyhemoglobin concentration [HHb] (proxy marker of metabolic stress), muscle cross-sectional area (CSA), activation, strength, architecture and edema before (T1), after 5 (T2), and 10 weeks (T3) of training with these protocols. Additionally, we analyzed the occurrence of association between muscle deoxygenation and muscle hypertrophy. Thirty young men were selected and each of participants’ legs was allocated to one of the three experimental protocols in a randomized and balanced way according to quartiles of the baseline CSA and leg extension 1-RM values of the dominant leg. The dynamic maximum strength was measured by 1-RM test and vastus lateralis (VL) muscle cross-sectional area CSA echo intensity (CSAecho) and pennation angle (PA) were performed through ultrasound images. The measurement of muscle activation by surface electromyography (EMG) and [HHb] through near-infrared spectroscopy (NIRS) of VL were performed during the training session with relative load obtained after the 1-RM, before (T1), after 5 (T2), and 10 weeks (T3) training. The training total volume (TTV) was greater for HL-RT and HL-BFR compared to LL-BFR. There was no difference in 1-RM, CSA, CSAecho, CSAecho/CSA, and PA increases between protocols. Regarding the magnitude of the EMG, the HL-RT and HL-BFR groups showed higher values than and LL-BFR. On the other hand, [HHb] was higher for HL-BFR and LL-BFR. In conclusion, our results suggest that the addition of BFR to exercise contributes to neuromuscular adaptations only when RT is performed with low-load. Furthermore, we found a significant association between the changes in [HHb] (i.e., metabolic stress) and increases in muscle CSA from T2 to T3 only for the LL-BFR, when muscle edema was attenuated

Acute changes in serum and skeletal muscle steroids in resistance-trained men

IntroductionResistance exercise can significantly increase serum steroid concentrations after an exercise bout. Steroid hormones are involved in the regulation of several important bodily functions (e.g., muscle growth) through both systemic delivery and local production. Thus, we aimed to determine whether resistance exercise-induced increases in serum steroid hormone concentrations are accompanied by enhanced skeletal muscle steroid concentrations, or whether muscle contractions per se induced by resistance exercise can increase intramuscular steroid concentrations.MethodsA counterbalanced, within-subject, crossover design was applied. Six resistance-trained men (26 ± 5 years; 79 ± 8 kg; 179 ± 10 cm) performed a single-arm lateral raise exercise (10 sets of 8 to 12 RM - 3 min rest between sets) targeting the deltoid muscle followed by either squat exercise (10 sets of 8 to 12 RM - 1 min rest) to induce a hormonal response (high hormone [HH] condition) or rest (low hormone [LH] condition). Blood samples were obtained pre-exercise and 15 min and 30 min post-exercise; muscle specimens were harvested pre-exercise and 45 min post-exercise. Immunoassays were used to measure serum and muscle steroids (total and free testosterone, dehydroepiandrosterone sulfate, dihydrotestosterone, and cortisol; free testosterone measured only in serum and dehydroepiandrosterone only in muscle) at these time points.ResultsIn the serum, only cortisol significantly increased after the HH protocol. There were no significant changes in muscle steroid concentrations after the protocols.DiscussionOur study provides evidence that serum steroid concentration increases (cortisol only) seem not to be aligned with muscle steroid concentrations. The lack of change in muscle steroid after protocols suggests that resistance-trained individuals were desensitized to the exercise stimuli. It is also possible that the single postexercise timepoint investigated in this study might be too early or too late to observe changes. Thus, additional timepoints should be examined to determine if RE can indeed change muscle steroid concentrations either by skeletal muscle uptake of these hormones or the intramuscular steroidogenesis process

Immune responses to an upper body tri‐set resistance training session

The purpose of this study was to evaluate the acute immune responses to an upper body tri-set resistance training (RT) session in RT trained individuals. Eighteen young trained men (22·0 ± 1·8 years) were randomly assigned to an exercise group (EG; n = 9) or control group (CG; n = 9). The EG completed an acute tri-set RT protocol using two combinations of three exercises for the same muscle group with six to eight repetitions at 75% of one repetition maximum (1RM) for each exercise. Blood samples were collected before (Pre), and 15 min (Post) and 24 h (P24h) after the acute RT protocol to determine basal and acute total leucocytes and leucocyte subsets counting, interleukin-6 (IL-6), tumour necrosis factor-α (TNF-α) and cortisol. There were significant increases in total leucocytes, monocytes and neutrophils at Post as compared with Pre (P<0·05). Additionally, total leucocytes and monocytes were reduced even at P24h when compared to Pre (P<0·05). There were no significant changes in plasma concentrations of TNF-α, IL-6 and cortisol throughout the measured moments. As compared to CG, EG demonstrated very large effect sizes for total leucocytes, neutrophils and monocytes 15 min postprotocol and a reduction (trivial and small effect sizes) P24h. These results suggest that the tri-set RT session did not exacerbate the acute inflammatory response and might be a good option for variations in RT methods for trained individuals3416471sem informaçã

Muscle fiber hypertrophy and myonuclei addition: a systematic review and meta-analysis

Introduction The myonuclear domain theory postulates that myonuclei are added to muscle fibers when increases in fiber cross-sectional area (i.e., hypertrophy) are ≥26%. However, recent studies have reported increased myonuclear content with lower levels (e.g., 12%) of muscle fiber hypertrophy. Purpose This study aimed to determine whether a muscle fiber hypertrophy "threshold" is required to drive the addition of new myonuclei to existing muscle fibers. Methods Studies of resistance training endurance training with or without nutrient (i.e., protein) supplementation and steroid administration with measures of muscle fiber hypertrophy and myonuclei number as primary or secondary outcomes were considered. Twenty-seven studies incorporating 62 treatment groups and 903 subjects fulfilled the inclusion criteria and were included in the analyses. Results Muscle fiber hypertrophy of ≤10% induces increases in myonuclear content, although asignificantly higher number of myonuclei are observed when muscle hypertrophy is 22%. Additional analyses showed that age, sex, and muscle fiber type do not influence muscle fiber hypertrophy or myonuclei addition. Conclusions Although a more consistent myonuclei addition occurs when muscle fiber hypertrophy is > 22%, our results challenge the concept of a muscle hypertrophy threshold as significant myonuclei addition occurs with lower muscle hypertrophy (i.e., < 10%

Time course of resistance training–induced muscle hypertrophy in the elderly

LixandrAo, ME, Damas, F, Chacon-Mikahil, MPT, Cavaglieri, CR, Ugrinowitsch, C, Bottaro, M, Vechin, FC, ConceicAo, MS, Berton, R, and Libardi, CA. Time course of resistance training-induced muscle hypertrophy in the elderly. J Strength Cond Res 30(1): 159-163, 2016Extended periods of resistance training (RT) induce muscle hypertrophy. Nevertheless, to date, no study has investigated the time window necessary to observe significant changes in muscle cross-sectional area (CSA) in older adults. Therefore, this study investigated the time course of muscle hypertrophy after 10 weeks (20 sessions) of RT in the elderly. Fourteen healthy older subjects were randomly allocated in either the RT (n: 6) or control group (n: 8). The RT was composed of 4 sets x 10 repetitions (70-80% 1 repetition maximum [1RM]) in a leg press machine. The time course of vastus lateralis muscle hypertrophy (CSA) was assessed on a weekly basis by mode-B ultrasonography. Leg press muscle strength was assessed by dynamic 1RM test. Our results demonstrated that the RT group increased leg press 1RM by 42% (p 0.05) after 10 weeks of training. Significant increases in vastus lateralis muscle CSA were observed only after 18 sessions of training (9 weeks; p 0.05; 7.1%). In conclusion, our training protocol promoted muscle mass accrual in older subjects, and this was only observable after 18 sessions of RT (9 weeks)301159163sem informaçã

Early metabolic response after resistance exercise with blood flow restriction in well-trained men: a metabolomics approach

The present study aimed to compare the early metabolic response between high-load resistance exercise (HL-RE) and low-load resistance exercise with blood flow restriction (LL-BFR). Nine young well-trained men participated in a randomized crossover design in which each subject completed LL-BFR, HL-RE or condition control (no exercise) with a one-week interval between them. Blood samples were taken immediately before and five minutes after the exercise sessions. Nuclear magnetic resonance (NMR) spectroscopy identified and quantified 48 metabolites, six of which presented significant changes among the exercise protocols. The HL-RE promoted a higher increase in pyruvate, lactate and alanine compared to the LL-BFR and the control. HL-RE and LL-BFR promoted a higher increase in succinate compared to the control, however, there was no difference between HL-RE and LL-BFR. Also, while there was no difference in acetoacetate between HL-RE and LL-BFR, a greater decrease was observed in both compared to the control. Finally, LL-BFR promoted a greater decrease in choline compared to the control. In conclusion, this study provides by metabolomics a new insight in metabolic response between LL-BFR and HL-RE by demonstrating a distinct response to some metabolites that are not commonly analyzed.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author