Mara Patrícia Traina Chacon-Mikahil

Effect of resistance, endurance, and concurrent training on TNF-α, IL-6, and CRP.

PURPOSE The aim of the present study was to evaluate the effects of 16 wk of resistance training (RT), endurance training (ET), and concurrent training (CT) on inflammatory markers, C-reactive protein (CRP), and functional capacity in sedentary middle-age men. METHODS Healthy subjects were randomized into RT (n = 11), ET (n = 12), CT (n = 11), and a control group (n = 13). The subjects performed three weekly sessions lasting about 60 min for 16 wk. Maximal strength was tested in bench press and leg press. The peak oxygen uptake (VO2peak) was measured in an incremental exercise test. Plasma tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and CRP levels were determined by an enzyme-linked immunosorbent assay. RESULTS Maximal strength was increased after 16 wk, with no differences between RT and CT. VO2peak increased in ET and CT comparing before and after training. There were no significant differences in TNF-α, IL-6, and CRP comparing before and after training. CONCLUSIONS Sixteen weeks of RT, ET, or CT in middle-age healthy men has not affected low and moderate IL-6, TNF-α, and CRP levels. CT performed in the same weekly frequency and session duration of ET and RT was effective in increasing both maximal strength and VO2peak, in addition to improvements in lipid profile.

Comparisons Between Low-intensity Resistance Training With Blood Flow Restriction and High-intensity Resistance Training on Quadriceps Muscle Mass and Strength in Elderly

Abstract Vechin, FC, Libardi, CA, Conceição, MS, Damas, FR, Lixandrão, ME, Berton, RPB, Tricoli, VAA, Roschel, HA, Cavaglieri, CR, Chacon-Mikahil, MPT, and Ugrinowitsch, C. Comparisons between low-intensity resistance training with blood flow restriction and high-intensity resistance training on quadriceps muscle mass and strength in elderly. J Strength Cond Res 29(4): 1071–1076, 2015—High-intensity resistance training (HRT) has been recommended to offset age-related loss in muscle strength and mass. However, part of the elderly population is often unable to exercise at high intensities. Alternatively, low-intensity resistance training with blood flow restriction (LRT-BFR) has emerged. The purpose of this study was to compare the effects of LRT-BFR and HRT on quadriceps muscle strength and mass in elderly. Twenty-three elderly individuals, 14 men and 9 women (age, 64.04 ± 3.81 years; weight, 72.55 ± 16.52 kg; height, 163 ± 11 cm), undertook 12 weeks of training. Subjects were ranked according to their pretraining quadriceps cross-sectional area (CSA) values and then randomly allocated into one of the following groups: (a) control group, (b) HRT: 4 × 10 repetitions, 70–80% one repetition maximum (1RM), and (c) LRT-BFR: 4 sets (1 × 30 and 3 × 15 repetitions), 20–30% 1RM. The occlusion pressure was set at 50% of maximum tibial arterial pressure and sustained during the whole training session. Leg press 1RM and quadriceps CSA were evaluated at before and after training. A mixed-model analysis was performed, and the significance level was set at p ⩽ 0.05. Both training regimes were effective in increasing pre- to post-training leg press 1RM (HRT: ∼54%, p < 0.001; LRT-BFR: ∼17%, p = 0.067) and quadriceps CSA (HRT: 7.9%, p < 0.001; LRT-BFR: 6.6%, p < 0.001); however, HRT seems to induce greater strength gains. In summary, LRT-BFR constitutes an important surrogate approach to HRT as an effective training method to induce gains in muscle strength and mass in elderly.

Sixteen weeks of resistance training can decrease the risk of metabolic syndrome in healthy postmenopausal women.

Background The postmenopausal phase has been considered an aggravating factor for developing metabolic syndrome. Notwithstanding, no studies have as yet investigated the effects of resistance training on metabolic syndrome in postmenopausal women. Thus, the purpose of this study was to verify whether resistance training could reduce the risk of metabolic syndrome in postmenopausal women. Methods Twenty postmenopausal women were randomly assigned to a resistance training protocol (n = 10, 53.40 ± 3.95 years, 64.58 ± 9.22 kg) or a control group (n = 10, 53.0 ± 5.7 years, 64.03 ± 5.03 kg). In the resistance training protocol, ten exercises were performed, with 3 × 8−10 maximal repetitions three times per week, and the load was increased every week. Two-way analysis of variance was used to evaluate specific metabolic syndrome Z-score, high density lipoprotein cholesterol, fasting blood glucose, triglycerides, waist circumference, blood pressure, strength, and body composition. The level of statistical significance was set at P < 0.05. Results The main results demonstrated a significant decrease of metabolic syndrome Z-score when the postmenopausal women performed resistance training (P = 0.0162). Moreover, we observed decreases in fasting blood glucose for the resistance training group (P = 0.001), and also significant improvements in lean body mass (P = 0.042, 2.46%), reduction of body fat percentage (P = 0.001, −6.75%) and noticeable increases in muscle strength after resistance training to leg press (P = 0.004, 41.29%) and bench press (P = 0.0001, 27.23%). Conclusion It was concluded that resistance training performed three times a week may reduce the metabolic syndrome Z-score with concomitant decreases in fasting blood glucose, improvements in body composition, and muscle strength in postmenopausal women.

Effect of Concurrent Training with Blood Flow Restriction in the Elderly

The aim of this present study was to investigate on the effects of concurrent training with blood flow restriction (BFR-CT) and concurrent training (CT) on the aerobic fitness, muscle mass and muscle strength in a cohort of older individuals. 25 healthy older adults (64.7±4.1 years; 69.33±10.8 kg; 1.6±0.1 m) were randomly assigned to experimental groups: CT (n=8, endurance training (ET), 2 days/week for 30-40 min, 50-80% VO(2peak) and RT, 2 days/week, leg press with 4 sets of 10 reps at 70-80% of 1-RM with 60 s rest), BFR-CT (n=10, ET, similar to CT, but resistance training with blood flow restriction: 2 days/week, leg press with 1 set of 30 and 3 sets of 15 reps at 20-30% 1-RM with 60 s rest) or control group (n=7). Quadriceps cross-sectional area (CSAq), 1-RM and VO(2peak) were assessed pre- and post-examination (12 wk). The CT and BFR-CT showed similar increases in CSAq post-test (7.3%, P<0.001; 7.6%, P<0.0001, respectively), 1-RM (38.1%, P<0.001; 35.4%, P=0.001, respectively) and VO(2peak) (9.5%, P=0.04; 10.3%, P=0.02, respectively). The BFR-CT promotes similar neuromuscular and cardiorespiratory adaptations as CT.

Effects of concurrent training on interleukin-6, tumour necrosis factor-alpha and C-reactive protein in middle-aged men

Abstract The purpose of this study was to evaluate the effects of moderate- to high-intensity resistance and concurrent training on inflammatory biomarkers and functional capacity in sedentary middle-aged healthy men. Participants were selected on a random basis for resistance training (n = 12), concurrent training (n = 11) and a control group (n = 13). They performed three weekly sessions for 16 weeks (resistance training: 10 exercises with 3 × 8–10 repetition maximum; concurrent training: 6 exercises with 3 × 8–10 repetition maximum, followed by 30 minutes of walking or running at 55–85% [Vdot]O2peak). Maximal strength was tested in bench press and leg press. The peak oxygen uptake ([Vdot]O2peak) was measured by an incremental exercise test. Tumour necrosis factor-α, interleukin-6 and C-reactive protein were determined. The upper- and lower-body maximal strength increase for both resistance (+42.52%; +20.9%, respectively) and concurrent training (+28.35%; +21.5%, respectively) groups (P = 0.0001).[Vdot]O2peak increased in concurrent training when comparing pre- and post-training (P = 0.0001; +15.6%). No differences were found in tumour necrosis factor-α and interleukin-6 for both groups after the exercise. C-reactive protein increased in resistance training (P = 0.004). These findings demonstrated that 16 weeks of moderate- to high-intensity training could improve functional capacity, but did not decrease inflammatory biomarkers in middle-aged men.

Time Course of Resistance Training-Induced Muscle Hypertrophy in the Elderly.

Abstract Lixandrão, ME, Damas, F, Chacon-Mikahil, MPT, Cavaglieri, CR, Ugrinowitsch, C, Bottaro, M, Vechin, FC, Conceição, 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, 2016—Extended 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 × 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).

Comparison of maximal muscle strength of elbow flexors and knee extensors between younger and older men with the same level of daily activity.

Background Aging promotes neuromuscular loss, significantly reducing muscle strength. The magnitude of loss of strength seems to be different between the limbs, probably because of differences in activities of daily living (ADL). Therefore, the present study compared the muscle strength of the elbow flexors and knee extensors in younger (n = 7, mean age 23.3 ± 1.2 years) and older (n = 5, mean age 61.8 ± 2.6 years) men matched by ADL level. Methods The study participants performed maximal concentric, isometric, and eccentric contractions of the elbow flexors and knee extensors using an isokinetic dynamometer following a crossover study design. Changes in the dependent variables were compared using mixed model analysis (limb versus age). Results The main results demonstrated that concentric, eccentric, and mean contraction torques for knee extensors were significantly (P < 0.05) higher for younger men than for elderly men. On the other hand, no statistically significant difference (P > 0.05) was found in concentric, isometric, eccentric, and mean torques for elbow flexors between younger and older individuals. Conclusion These results show that elbow flexors maintain better strength than knee extensors through aging, even when comparing individuals with similar ADL levels.

Combined Training Reduces Subclinical Inflammation in Obese Middle-Age Men

PURPOSE We investigated the effects of 24 wk of combined training on proinflammatory and anti-inflammatory markers associated with obesity in obese middle-age men. METHODS Thirty obese men (48.73 ± 1.04 yr; body mass index, 31.00 ± 0.29 kg·m) underwent 24 wk of combined training [CT (N = 17), aerobic (50%-85% of V˙O2peak) and resistance (6-10 maximum repetition [RM]) training)] three times per week, 60 min per session, or a control group (N = 13). Anthropometric measures, maximal strength for leg press and bench press, peak oxygen uptake (V˙O2peak) and serum concentrations of C-reactive protein (CRP), tumor necrosis factor α (TNF-α), interleukin-6 (IL-6), IL-10, IL-15, resistin, leptin, and adiponectin were determined before (M1) and after 8 (M2), 16 (M3), and 24 (M4) wk of the experimental design. RESULTS Significant increases were observed in the maximal strength for bench press and leg press, V˙O2peak, and serum concentrations of adiponectin and IL-15 for CT. Concomitantly, significant decreases were observed in percentage body fat and serum concentrations of CRP, resistin, and leptin for CT after the experimental period. CONCLUSION Twenty-four weeks of moderate- to high-intensity CT reduced markers of subclinical inflammation associated with obesity and improved insulin resistance and functional capabilities of obese middle-age men, regardless of dietary intervention and weight loss.

Electromyographic activity and rate of muscle fatigue of the quadriceps femoris during cycling exercise in the severe domain.

Camata, TV, Altimari, LR, Bortolotti, H, Dantas, JL, Fontes, EB, Smirmaul, BPC, Okano, AH, Chacon-Mikahil, MPT, and Moraes, AC. Electromyographic activity and rate of muscle fatigue of the quadriceps femoris during cycling exercise in the severe domain. J Strength Cond Res 25(9): 2537-2543, 2011—This study compared the activation pattern and the fatigue rate among the superficial muscles of the quadriceps femoris (QF) during severe cycling exercise. Peak oxygen consumption (&OV0312;o2peak) and maximal accumulated oxygen Deficit (MAOD) were established by 10 well-trained male cyclists (27.5 ± 4.1 years, 71.0 ± 10.3 kg, 173.4 ± 6.6 cm, mean &OV0312;o2peak 56.7 ± 4.4 ml·kg−1·min−1, mean MAOD 5.7 ± 1.1 L). Muscle activity (electromyographic [EMG] signals) was obtained during the supramaximal constant workload test (MAOD) and expressed by root mean square (RMS) and median frequency (MF slope). The RMS of the QF, vastus lateralis (VL) and vastus medialis (VM) muscles were significantly higher than at the beginning after 75% of exercise duration, whereas for the rectus femoris (RF), this was observed after 50% of exercise duration (p ≤ 0.05). The slope of the MF was significantly higher in the RF, followed by the VL and VM (−3.13 ± 0.52 vs. −2.61 ± 0.62 vs. −1.81 ±0.56, respectively; p < 0.05). We conclude that RF may play an important role in limiting performance during severe cycling exercise.

Vastus lateralis muscle cross-sectional area ultrasonography validity for image fitting in humans.

Abstract Lixandrão, ME, Ugrinowitsch, C, Bottaro, M, Chacon-Mikahil, MPT, Cavaglieri, CR, Min, LL, de Souza, EO, Laurentino, GC, and Libardi, CA. Vastus lateralis muscle cross-sectional area ultrasonography validity for image fitting in humans. J Strength Cond Res 28(11): 3293–3297, 2014—The present study aimed to determine the concurrent validity of ultrasound (US) measurement of the vastus lateralis muscle (VL) cross-sectional area (CSA) having magnetic resonance imaging (MRI) as the gold standard measurement, in a heterogeneous sample of participants. Thirty-one individuals (52.44 ± 16.37 years; 1.67 ± 0.11 m; 75.25 ± 13.82 kg) volunteered to participate in the study. All the images were performed in the right leg. Image-fitting technique (US) and computerized planimetry technique (US and MRI) were used to determine the VL CSA. The typical error (TE) of measurement was used to determine the concurrent validity of the US measurements. Our results demonstrated good validity of the US compared with the MRI measurements (TE = 0.37 cm2; coefficient of variation = 1.75%). The Bland-Altman plot demonstrated bias of 0.07 ± 0.53 cm2 and limits of agreement of 0.96–1.11 cm2. Based on our TE, bias and limits of agreement, we concluded that the US image-fitting technique is valid to assess the VL CSA in a heterogeneous sample of participants. Thereby, US can be used instead of MRI to assess changes in skeletal muscle morphology.