Storage Duration Affects the Quantification of Oxidative Stress Markers in the Gastrocnemius, Heart, and Brain of Mice Submitted to a Maximum Exercise.

This study investigated the effect of sample storage duration on the quantification of oxidative stress markers in the gastrocnemius, heart, and brain of mice submitted to a maximum swimming exercise. Thiobarbituric acid reactive substances (TBARSs), protein carbonyl derivatives, total antioxidant capacity (TAC), and the activity of superoxide dismutase (SOD) and catalase (CAT) were quantified in fresh tissues and in samples stored at -80°C for 1, 3, or 6 months, from exercised (n = 13) and nonexercised mice (n = 13). Except for protein carbonyl derivatives in the heart, the exercise resulted in the modification of all markers in all fresh-evaluated samples (p < 0.001). The storage duration did not modify the effect of exercise on protein carbonyl derivatives and TAC. TBARS was stable for 3 months in the gastrocnemius and for 1 month in frozen heart and brain. Accordingly, the exercise effect on TBARS levels observed in fresh samples was absent in the gastrocnemius frozen for 6 months (p = 0.98) and in the heart and brain frozen for 3 months (p = 0.07 and 0.28, respectively) or more (p = 0.21 for heart and p > 0.99 for brain). In addition, CAT and SOD activities were reduced by storage duration in all tissues evaluated (p < 0.05). Our findings show that sample storage duration alters the quantification of oxidative stress markers in mice submitted to maximum exercise, and its effect is tissue and marker dependent. Some recommendations to achieve more accurate and reproducible data in the exercise physiology and oxidative stress markers field are presented.

Efficacy of Whole-Body Vibration Training on Brain-Derived Neurotrophic Factor, Clinical and Functional Outcomes, and Quality of Life in Women with Fibromyalgia Syndrome: A Randomized Controlled Trial.

This study aimed to investigate the efficacy of whole-body vibration training (WBVT) on blood brain-derived neurotrophic factor (BDNF) levels and determine the clinical and functional outcomes in patients with fibromyalgia syndrome (FMS). Thirty-two women with FMS were randomized into an intervention group (IG), receiving 6 weeks of WBVT, or a control group (CG) with no intervention. The outcomes at the baseline and follow-up in both groups included blood BDNF levels, sit-to-stand test (STS), 6-minute walk test (6MWT), Fibromyalgia Impact Questionnaire (FIQ), Pittsburgh Sleep Quality Index (PSQI), Beck Depression Inventory (BDI), and visual analogue scale (VAS). WBVT resulted in a group-by-time interaction effect. Thus, after the intervention time, the IG had increased blood BDNF levels (p=0.045), a higher number of repetitions on the STS test (p=0.011), and increased walking distance on the 6MWT (p=0.010), compared to CG. Moreover, there was a reduction in the scores of the FIQ (p=0.001), the PSQI (p=0.001), the BDI (p=0.017), and pain assessed using VAS (p=0.008) in IG. The results demonstrate that WBVT promotes an increase in blood BDNF levels, with concomitant improvement in lower limb muscle strength, aerobic capacity, clinical symptoms, and quality of life in women with FMS. This trial is registered with Brazilian Clinical Trials Registry (REBEC; RBR-38nbbx) (https://ensaiosclinicos.gov.br/rg/RBR-38nbbx).

High-intensity interval training followed by postexercise cold-water immersion does not alter angiogenic circulating cells, but increases circulating endothelial cells.

High-intensity interval training (HIIT) induces vascular adaptations that might be attenuated by postexercise cold-water immersion (CWI). Circulating angiogenic cells (CAC) participate in the vascular adaptations and circulating endothelial cells (CEC) indicate endothelial damage. CAC and CEC are involved in vascular adaptation. Therefore, the aim of the study was to investigate postexercise CWI during HIIT on CAC and CEC and on muscle angiogenesis-related molecules. Seventeen male subjects performed 13 HIIT sessions followed by 15 min of passive recovery (n = 9) or CWI at 10 °C (n = 8). HIIT comprised cycling (8-12 bouts, 90%-110% peak power). The first and the thirteenth sessions were similar (8 bouts at 90% of peak power). Venous blood was drawn before exercise (baseline) and after the recovery strategy (postrecovery) in the first (pretraining) and in the thirteenth (post-training) sessions. For CAC and CEC identification lymphocyte surface markers (CD133, CD34, and VEGFR2) were used. Vastus lateralis muscle biopsies were performed pre- and post-training for protein (p-eNOSser1177) and gene (VEGF and HIF-1) expression analysis related to angiogenesis. CAC was not affected by HIIT or postexercise CWI. Postexercise CWI increased acute and baseline CEC number. Angiogenic protein and genes were not differently modulated by post-CWI. HIIT followed by either recovery strategy did not alter CAC number. Postexercise CWI increased a marker of endothelial damage both acutely and chronically, suggesting that this postexercise recovery strategy might cause endothelial damage. Novelty HIIT followed by CWI did not alter CAC. HIIT followed by CWI increased CEC. Postexercise CWI might cause endothelial damage.

Effect of a Moderate-Intensity Aerobic Training on Joint Biomarkers and Functional Adaptations in Rats Subjected to Induced Knee Osteoarthritis.

BACKGROUND: Knee osteoarthritis (kOA) is a common chronic disease that induces changes in redox status and inflammatory biomarkers, cell death, and motor impairment. Aerobic training can be a non-pharmacological alternative to prevent the progression of the disease. OBJECTIVE: To evaluate the effects of an 8 weeks moderate-intensity treadmill aerobic training program on redox status and inflammatory biomarkers and motor performance in kOA-like changes induced by monosodium iodoacetate (MIA) in rats. METHODS: Twenty-seven rats were randomly divided into three groups: SHAM; induced kOA (OA); and induced kOA + aerobic training (OAE). Motor performance was evaluated by the number of falls on rotarod test, the total time of displacement and the number of failures on a 100 cm footbridge. Data for cytokines and histology were investigated locally, whereas plasma was used for redox status biomarkers. RESULTS: The OA group, compared to the SHAM group, increased 1.13 times the total time of displacement, 6.05 times the number of failures, 2.40 times the number of falls. There was also an increase in cytokine and in thiobarbituric acid reactive substances (TBARS) (IL1ß: 5.55-fold, TNF: 2.84-fold, IL10: 1.27-fold, IL6: 1.50-fold, TBARS: 1.14-fold), and a reduction of 6.83% in the total antioxidant capacity (FRAP), and of 35% in the number of chondrocytes. The aerobic training improved the motor performance in all joint function tests matching to SHAM scores. Also, it reduced inflammatory biomarkers and TBARS level at values close to those of the SHAM group, with no change in FRAP level. The number of falls was explained by IL1ß and TNF (58%), and the number of failures and the total time of displacement were also explained by TNF (29 and 21%, respectively). CONCLUSION: All findings indicate the efficacy of moderate-intensity aerobic training to regulate inflammatory biomarkers associated with improved motor performance in induced kOA-like changes, thus preventing the loss of chondrocytes.

Whole Body Vibration Training on Muscle Strength and Brain-Derived Neurotrophic Factor Levels in Elderly Woman With Knee Osteoarthritis: A Randomized Clinical Trial Study.

Background: Osteoarthritis of the knee (kOA) is a chronic, progressive, degenerative health condition that contributes to the imbalance between the synthesis and destruction of articular cartilage. Recently, whole body vibration (WBV) training has been recommended as an effective alternative for strength training in elderly people, and various physiological effects are obtained in response to exercise performed on a vibratory platform, such as an increase in muscle activation and improved muscle performance. However, the effects of WBV particularly on the strength of the quadriceps muscle and neuronal plasticity are unknown. Objective: The aim of this study was to evaluate the effects of adding WBV to squat training on the isometric quadriceps muscle strength (IQMS) and the plasma levels of brain-derived neurotrophic factor (BDNF) in elderly woman with kOA. Methods: Fifteen elderly women ≥65 years of age with kOA were randomized into two interventions: (1) the vibration group (VG), in which participants performed squat exercise training in association with WBV or (2) the exercise group (EG), in which participants performed squat exercise training without vibration, for 12 weeks 3×/week. Results: Compared to the EG group, the VG group demonstrated a significantly greater delta (Δ) in IQMS values (IC95% 0.43-7.06; p ≤ 0.05) and in Δ BDNF plasma levels (IC95% -32.51 to 4.217; p ≤ 0.05) after the intervention period. There was an association between increase of Δ BDNF plasma levels and increase of Δ IQMS (ß = 0.57; R 2 = 0.32; p = 0.03). Conclusion: The addition of WBV to squat exercise training improves lower limb muscle performance in elderly women with kOA. These findings suggest that the improvement in muscle performance is related to neuromuscular adaptations induced by WBV. Clinical Trial Registration: www.ClinicalTrials.gov, identifier NCT03918291.

Late Neutrophil Priming Following a Single Session of High-intensity Interval Exercise.

This study evaluated the effect of an acute high-intensity interval exercise (HIIE) session on the function of human neutrophils. Twelve sedentary men performed a HIIE session (8 bouts of 60 s at 90% of peak power, intercalated with 75 s of active recovery at 30 W). Neutrophils were collected before, 30 min and 24 h after the exercise session for the evaluation of phagocytic capacity, expression of phagocytic receptors, reactive oxygen species generation, and redox status. 24 h after the HIIE session, an increase was observed in both neutrophil phagocytic capacity and yeast-induced generation of reactive oxygen species, which indicates neutrophil priming in response to an acute HIIE session. Neutrophils also presented an increase in superoxide dismutase activity 24 h after the exercise. Improvement in neutrophil function was accompanied by increased serum levels of IL-8 and increased concentration of plasma lactate dehydrogenase. Our findings show a late activating effect of one HIIE session on neutrophils. We propose that priming of neutrophils by HIIE may play a role in skeletal muscle inflammation after exercise.

Neuroendocrine Inflammatory Responses in Overweight/Obese Infants.

Childhood obesity is related to a cascade of neuroendocrine inflammatory changes. However, there remains a gap in the current literature regarding the possible occurrence of these changes in overweight/obese infants. The objective of this study was to evaluate adipokines, cortisol, brain-derived neurotrophic factor (BDNF) and redox status in overweight/obese infants versus normal-weight peers. A cross-sectional study was conducted with 50 infants (25 in the overweight/obese group and 25 in the normal-weight group) between 6 and 24 months. Plasma levels of leptin, adiponectin, resistin, soluble tumor necrosis factor (TNF) receptors, chemokines, BDNF, serum cortisol and redox status were measured. Unpaired Student's t-test was used to analyze the results and a probability of p<0.05 was acceptable for rejection of the null hypothesis. The Pearson correlation was used to verify the association between the biomarkers analyzed in each group. Plasma levels of leptin (p = 0.0001), adiponectin (p = 0.0007) and BDNF (p = 0.003), and serum cortisol (p = 0.048) were significantly higher in overweight/obese infants than normal-weight infants. In contrast, the concentration of thiobarbituric acid reactive substances (TBARS) (p = 0.004), and catalase (p = 0.045) and superoxide dismutase activity (p = 0.02) were lower in overweight/obese infants than normal-weight peers. All the results together indicate neuroendocrine inflammatory response changes in overweight/obese infants between 6 and 24 months. Although there is already an environment that predisposes for a subsequent pro-inflammatory response, neuroendocrine secretion changes that permit the control of the inflammatory process in this age interval can be observed.

Lymphocyte Redox Imbalance and Reduced Proliferation after a Single Session of High Intensity Interval Exercise.

This study investigated whether an acute session of high-intensity interval training (HIIT) is sufficient to alter lymphocyte function and redox status. Sixteen young healthy men underwent a HIIT session on a cycloergometer, consisting of eight bouts of 1 min at 90-100% of peak power, with 75 seconds of active recovery at 30 W between bouts. Venous blood was collected before, immediately after, and 30 minutes after the HIIT session. In response to Staphylococcus aureus superantigen B (SEB) stimulation, lymphocyte proliferation decreased and the IL-2 concentration increased after the HIIT session. However, the HIIT session had no effect on lymphocyte proliferation or IL-2 response to phytohemagglutinin stimulation. The HIIT session also induced lymphocyte redox imbalance, characterized by an increase in the concentration of thiobarbituric acid reactive substances and a decrease in the activity of the antioxidant enzyme catalase. Lymphocyte viability was not affected by the HIIT session. The frequencies of CD25+ and CD69+ T helper and B lymphocytes in response to superantigen stimulation were lower after exercise, suggesting that superantigen-induced lymphocyte activation was reduced by HIIT. However, HIIT also led to a reduction in the frequency of CD4+ and CD19+ cells, so the frequencies of CD25+ and CD69+ cells within the CD4 and CD19 cell populations were not affected by HIIT. These data indicate that the reduced lymphocyte proliferation observed after HIIT is not due to reduced early lymphocyte activation by superantigen. Our findings show that an acute HIIT session promotes lymphocyte redox imbalance and reduces lymphocyte proliferation in response to superantigenic, but not to mitogenic stimulation. This observation cannot be explained by alteration of the early lymphocyte activation response to superantigen. The manner in which lymphocyte function modulation by an acute HIIT session can affect individual immunity and susceptibility to infection is important and requires further investigation.

Influence of the knee flexion on muscle activation and transmissibility during whole body vibration.

The influence of the knee flexion on muscle activation and transmissibility during whole body vibration is controversially discussed in the literature. In this study, 34 individuals had electromyography activity (EMG) of the vastus lateralis and the acceleration assessed while squatting with 60° and 90° of knee flexion either with or without whole-body vibration (WBV). The conditions were maintained for 10s with 1min of rest between each condition. The main findings were (1) the larger the angle of knee flexion (90° vs. 60°), the greater the EMG (p<0.001), with no difference on acceleration transmissibility; (2) for both angles of knee flexion, the addition of WBV produced no significant difference in EMG and higher acceleration compared to without WBV (p<0.001). These results suggest that the larger the knee flexion angle (60° vs. 90°), the greater the muscle activation without acceleration modification. However, the addition of WBV increases the transmissibility of acceleration in the lower limbs without modification in EMG of vastus lateralis.

Functional performance and inflammatory cytokines after squat exercises and whole-body vibration in elderly individuals with knee osteoarthritis.

OBJECTIVE: To investigate the effects of squat exercises combined with whole-body vibration on the plasma concentration of inflammatory markers and the functional performance of elderly individuals with knee osteoarthritis (OA). DESIGN: Clinical, prospective, randomized, single-blinded study. SETTING: Exercise physiology laboratory. PARTICIPANTS: Elderly subjects with knee OA (N=32) were divided into 3 groups: (1) squat exercises on a vibratory platform (platform group, n=11); (2) squat exercises without vibration (squat group, n=10); and (3) the control group (n=11). INTERVENTIONS: The structured program of squat exercises in the platform and squat groups was conducted 3 times per week, on alternate days, for 12 weeks. MAIN OUTCOME MEASURES: Plasma soluble tumor necrosis factor-α receptors 1 (sTNFR1) and 2 (sTNFR2) were measured using immunoassays (the enzyme-linked immunosorbent assay method). The Western Ontario and McMaster Universities Osteoarthritis Index questionnaire was used to evaluate self-reported physical function, pain, and stiffness. The 6-minute walk test, the Berg Balance Scale, and gait speed were used to evaluate physical function. RESULTS: In the platform group, there were significant reductions in the plasma concentrations of the inflammatory markers sTNFR1 and sTNFR2 (P<.001 and P<.05, respectively) and self-reported pain (P<.05) compared with the control group, and there was an increase in balance (P<.05) and speed and distance walked (P<.05 and P<.001, respectively). In addition, the platform group walked faster than the squat group (P<.01). CONCLUSIONS: The results suggest that whole-body vibration training improves self-perception of pain, balance, gait quality, and inflammatory markers in elderly subjects with knee OA.

The effects of passive warm-up vs. whole-body vibration on high-intensity performance during sprint cycle exercise.

The purpose of this study was to compare the effects of passive warm-up (PW), whole-body vibration (WBV), and control (C) on high-intensity performance during sprint cycle exercise. Six recreationally trained men performed a 30-second sprint cycle test after the 3 aforementioned conditions; each test was carried out on a different day after balanced-order experimental tests. The WBV consisted of 5 minutes of squats associated with WBV (45 Hz, 2 mm). The PW consisted of 30 minutes of PW using a thermal blanket on the thighs and legs (35 W). The C consisted of 30 minutes of no warm-up with the subject lying down. Motor neuron excitability from the vastus lateralis muscle, evaluated by electromyography (EMG), was determined before exercise at rest and during sprint cycle exercise. Blood lactate levels (BLs), evaluated by spectroscopy, and muscle temperature (MT) of the thigh, estimated indirectly by measuring skin temperature, were determined at following time points: before exercise at rest (before and after experimental conditions), immediately, and 3 minutes after the 30-second sprint cycle test. Peak power, relative power, relative work, time of peak power, and pedaling cadence were significantly higher in the WBV compared with that for C (p < 0.05). Although MT was significantly greater in PW compared with that in WBV and C before exercise (p < 0.01), no significant differences were observed between the experimental conditions for BL immediately after sprint cycle exercise (p = 0.35) and in EMG during sprint cycle exercise (p = 0.16). Thus, it is plausible to suggest WBV as a method for an acute increase in high-intensity performance during sprint cycle exercise for athletes immediately before competition or training.

Oxygen consumption and heart rate during repeated squatting exercises with or without whole-body vibration in the elderly.

Avelar, NCP, Simão, AP, Tossige-Gomes, R, Neves, CDC, Mezencio, B, Szmuchrowski, L, Coimbra, CC, and Lacerda, ACR. Oxygen consumption and heart rate during repeated squatting exercises with or without whole-body vibration in the elderly. J Strength Cond Res 25(12): 3495-3500, 2011-The aim of this study was to investigate whether vibration plus squatting would increase cardiovascular demand to the optimal exercise limits needed for the prescription of cardiovascular training. Oxygen consumption, measured breath by breath by a portable gas analysis system, and heart rate (HR), measured using an HR monitor, were evaluated in 18 elderly individuals, 15 women and 3 men with a mean age of 72 ± 6 years. These variables were measured simultaneously and at the same time points in each subject during rest and randomly during the performance of squatting exercises (8 series of 40 seconds, with 40 seconds of rest between series of performing squats in 3-second cycles with 10-60° of flexion, a total of 5 repetitions for 40 seconds) with or without vibration at a frequency of 40 Hz and amplitude of 4 mm, separated by at least 1 day. Associating whole-body vibration with squatting exercise resulted in an additional increase of around 20% in oxygen consumption and 7.5% in the HR recorded during exercise. However, during squatting exercise with vibration, the increase achieved in oxygen consumption was limited to around 2 metabolic equivalents, and mean HR represented around 56% of the predicted maximum HR for age. The results of this study show that, despite the fact that vibration increased oxygen consumption and HR during the performance of squatting exercise, the minimum standards of intensity for the prescription of physical exercise with the specific objective of improving cardiorespiratory fitness were not achieved. Therefore, a protocol such as that used in the study does not meet the threshold for cardiovascular training prescription.

The effect of adding whole-body vibration to squat training on the functional performance and self-report of disease status in elderly patients with knee osteoarthritis: a randomized, controlled clinical study.

OBJECTIVES: The study objectives were to evaluate the effects of adding whole-body vibration to squat training on functional performance and self-report of disease in elderly individuals with knee osteoarthritis (OA). DESIGN: This was a prospective, randomized trial in which selected variables were evaluated at three periods: 3 weeks prior to the training, immediately prior, and after the end of the training. SUBJECTS: Twenty-three (23) elderly subjects were evaluated using four functional performance tests: Berg Balance Scale (BBS), Timed Get Up and Go Test (TGUG), Chair Stand Test (CST), and 6-Minute Walk Test (6MWT), and a self-report of the status of disease (WOMAC). INTERVENTIONS: The intervention lasted for 12 weeks, 3 times per week. The participants were randomized into two groups: (1) squat training with whole-body vibration, and (2) squat training without vibration. RESULTS: Although there was no statistical difference in functional performance and self-report of disease status between the groups, performance in all the functional tests and in all the domains of WOMAC improved in the vibration group compared to their initial status. In the exercise group, performance improved only two tests (BBS and 6MWT), and there was a reduction in self-reported pain (WOMAC) compared to their initial status. CONCLUSIONS: Although the addition of whole-body vibration to squat training failed to result in a significant improvement in functional performance and self-reported status of knee osteoarthritis in the elderly, the intragroup results suggest that whole-body vibration may represent a feasible and effective way of improving the functionality and self-perception of disease status in older adults with knee OA.