Ramires Alsamir Tibana

Higher muscle performance in adolescents compared with adults after a resistance training session with different rest intervals.

Abstract Tibana, RA, Prestes, J, da Cunha Nascimento, D, Martins, OV, de Santana, FS, and Balsamo, S. Higher muscle performance in adolescents compared with adults after a resistance training session with different rest intervals. J Strength Cond Res 26(4): 1027–1032, 2012—The aim of the present study was to compare the effect of 3 different rest intervals between sets on the total training volume, number of repetitions, ratings of perceived exertion (RPE), and resistance to fatigue in adolescents and adults during a resistance training session in the isoinertial chest press exercise. Fifteen male adolescents (15.2 ± 1.2 years; 20.7 ± 2.0 kg·m−2; Tanner −4; 61.5 ± 8.9, 10 repetition maximum [RM]) and 15 adults (22.2 ± 2.7 years; 23.3 ± 2.0 kg·m−2; Tanner −5; 84.3 ± 13.5, 10RM) without previous experience with resistance training participated in the study. After 10RM test-retest on 3 different occasions, participants were randomly assigned to a resistance training protocol with 30-, 60-, and 120-second rest interval between sets. The protocol consisted of 3 sets with 10RM. In all studied variables, with exception to total training volume and RPE, adolescents presented superior results as compared with adults (p < 0.001). On the other hand, both adults and adolescents exhibited a higher resistance to fatigue, total training volume, and number of repetitions with a longer rest interval (120 > 60 > 30 seconds) (p < 0.01). Thus, these results indicate that adolescents present a higher recovery capacity between sets in a resistance training session than adults and a longer rest interval results in a higher number of repetitions completed, total training volume, and resistance to fatigue.

Decreased functional capacity and muscle strength in elderly women with metabolic syndrome

Purpose To compare the metabolic parameters, flexibility, muscle strength, functional capacity, and lower limb muscle power of elderly women with and without the metabolic syndrome (MetS). Methods This cross-sectional study included 28 older women divided into two groups: with the MetS (n = 14; 67.3 ± 5.5 years; 67.5 ± 16.7 kg; 1.45 ± 0.35 m; 28.0 ± 7.6 kg/m2), and without the MetS (n = 14; 68.7 ± 5.3 years; 58.2 ± 9.9 kg; 1.55 ± 0.10 m; 24.3 ± 3.8 kg/m2). Body composition was evaluated by dual-energy X-ray absorptiometry and dynamic muscle strength was assessed by one-maximum repetition (1RM) tests in leg press, bench press and biceps curl exercises. Six-minute walk test, Timed Up and Go (TUG); 30-second sitting-rising; arm curl using a 2-kg dumbbell, sit-and-reach (flexibility), and vertical jump tests were performed. Results There was no difference between groups regarding age (P = 0.49), height (P = 0.46), body fat (%) (P = 0.19), systolic (P = 0.64), diastolic (P = 0.41) and mean blood pressure (P = 0.86), 30-second sitting-rising (P = 0.57), 30-s arm curl (P = 0.73), leg press 1RM (P = 0.51), bench press 1RM (P = 0.77), and biceps curl 1RM (P = 0.85). However, women without the MetS presented lower body mass (P = 0.001), body mass index (BMI) (P = 0.0001), waist circumference (P = 0.02), waist-to-height ratio (P = 0.02), fat body mass (kg) (P = 0.05), lean body mass (kg) (P = 0.02), blood glucose (P = 0.05), triglycerides (P = 0.03), Z-score for the MetS (P = 0.05), higher high-density lipoprotein-cholesterol (HDL-C) (P = 0.002), better performance on TUG (P = 0.01), flexibility (P = 0.03), six-minute walk test (P = 0.04), vertical jump (P = 0.05) and relative muscle strength for leg press (P = 0.03), bench press (P = 0.04) and biceps curl (P = 0.002) exercises as compared to women with the MetS. Conclusion Elderly women with the MetS have higher metabolic risk profile and lower functional capacity, muscle strength, lower limb power and flexibility as compared to women without the MetS. The evaluation of functional capacity may help to determine the degree of physical decline in older persons with the MetS, while exercise interventions should be encouraged.

Relação da circunferência do pescoço com a força muscular relativa e os fatores de risco cardiovascular em mulheres sedentárias

OBJECTIVE To verify the relation of neck circumference and relative muscle strength and cardiovascular risk factors in sedentary women. METHODS A cross-sectional study with 60 premenopausal women (33.9±9.1 years; 67.4±13.6kg; 1.57±0.6cm and 27.2±5.3kg/m²). Based on the neck circumference, the sample was divided into two groups: Group Circumference <35cm (n=27) and Group Circumference >35cm (n=33) to compare relative muscle strength and cardiovascular risk factors. The correlation between variables was tested by Pearson and Spearman correlations, with a significance level established at p<0.05. RESULTS The findings revealed that women with neck circumference >35cm presented higher values of body mass, waist circumference, body adiposity index, body mass index, systolic blood pressure, blood glucose, glycated hemoglobin and volume of visceral fat when compared with the group with neck circumference <35cm. Additionally, the group with larger neck circumference presented lower values of relative strength. CONCLUSION Neck circumference seems to be an important predictive factor of cardiovascular risk and of relative strength loss in middle-aged sedentary women.

Acute effects of resistance exercise on 24-h blood pressure in middle aged overweight and obese women.

This investigation was designed to evaluate responses of blood pressure (BP) following an acute resistance exercise (RE) session. Middle-aged women (N=13) who were classified as overweight (N=8) or obese (N=5) according to body mass index (BMI) participated in the investigation. Participants were randomly submitted to a control session (30-min seated rest) and a exercise session (3 sets, 10 repetitions at 60% 1RM of exercises for the upper and lower body) with systolic (SBP), diastolic (DBP) and mean blood pressure (MBP) obtained at rest and 10, 20, 30, 40, 50, and 60-min following exercise, and through 24 h. Acute RE decreased SBP at 10, 30, and 40-min compared with pre-exercise and control (P<0.05). DBP decreased at 10 and 40-min post-exercise compared with the control trial (P<0.05). Both SBP and DBP decreased in the nighttime period (-4.2 mmHg and -4.1 mmHg, respectively) and in the overall 24 h period (-3.6 mmHg and -4.5 mmHg, respectively) following the acute RE session when compared with the control trial. These findings indicate important benefits of acute RE on BP circadian rhythm, particularly at night as well as in the morning, which are critical periods associated with increased risk for cardiovascular events.

Exercise order affects the total training volume and the ratings of perceived exertion in response to a super-set resistance training session

The super-set is a widely used resistance training method consisting of exercises for agonist and antagonist muscles with limited or no rest interval between them – for example, bench press followed by bent-over rows. In this sense, the aim of the present study was to compare the effects of different super-set exercise sequences on the total training volume. A secondary aim was to evaluate the ratings of perceived exertion and fatigue index in response to different exercise order. On separate testing days, twelve resistance-trained men, aged 23.0 ± 4.3 years, height 174.8 ± 6.75 cm, body mass 77.8 ± 13.27 kg, body fat 12.0% ± 4.7%, were submitted to a super-set method by using two different exercise orders: quadriceps (leg extension) + hamstrings (leg curl) (QH) or hamstrings (leg curl) + quadriceps (leg extension) (HQ). Sessions consisted of three sets with a ten-repetition maximum load with 90 seconds rest between sets. Results revealed that the total training volume was higher for the HQ exercise order (P = 0.02) with lower perceived exertion than the inverse order (P = 0.04). These results suggest that HQ exercise order involving lower limbs may benefit practitioners interested in reaching a higher total training volume with lower ratings of perceived exertion compared with the leg extension plus leg curl order.

Acute effects of resistance training on cytokines and osteoprotegerin in women with metabolic syndrome

Chronic inflammation has been identified as an important component of metabolic syndrome (MetS). Inhibition of the inflammatory mediator signals is a promising strategy against insulin resistance, atherosclerosis and other problems associated with MetS. Regular exercise decreases the components associated with MetS, including inflammatory cytokines. However, the relationship between an acute resistance training (RT) session, cytokine levels and MetS is unclear. Therefore, the aim was to evaluate the effects of a single bout of acute RT on tumour necrosis factor (TNF‐α), interleukins (IL) IL‐1a, IL‐1β, IL‐12, IL‐6, IL‐10 and osteoprotegerin (OPG) in women with MetS. Twenty‐four women were divided into 2 groups: metabolic syndrome (MetS) and non‐metabolic syndrome (Non‐MetS). After the familiarization and testing for 1 repetition maximum (1RM), participants completed 3 sets of 10 repetitions in the following exercises: machine leg press, leg extension, leg curl, chest press, lat front pull‐down and machine shoulder press with 60% of 1RM followed by 15 repetitions of abdominal crunches. A rest interval of 1 min was allowed between sets and exercises. Plasma TNF‐α, IL‐1a, IL‐1β, IL‐12, IL‐6, IL‐10 and OPG were measured before, immediately post and 60 min after RT. MetS group showed significantly higher concentrations of IL‐1β (P = 0·024) and IL‐6 (P = 0·049) and a trend for higher TNF‐α values (P = 0·092) compared with Non‐MetS. There was no group × time interactions after the RT session on the measured cytokines and osteoprotegerin. In conclusion, acute RT session induced no additional increase in pro‐inflammatory cytokines nor a decrease in anti‐inflammatory cytokines and OPG in women with MetS.

Low dynamic muscle strength and its associations with fatigue, functional performance, and quality of life in premenopausal patients with systemic lupus erythematosus and low disease activity: a case–control study

BackgroundThe purpose of the present study was to compare dynamic muscle strength, functional performance, fatigue, and quality of life in premenopausal systemic lupus erythematosus (SLE) patients with low disease activity versus matched-healthy controls and to determine the association of dynamic muscle strength with fatigue, functional performance, and quality of life in SLE patients.MethodsWe evaluated premenopausal (18–45 years) SLE patients with low disease activity (Systemic lupus erythematosus disease activity index [SLEDAI]: mean 1.5 ± 1.2). The control (n = 25) and patient (n = 25) groups were matched by age, physical characteristics, and the level of physical activities in daily life (International Physical Activity Questionnaire IPAQ). Both groups had not participated in regular exercise programs for at least six months prior to the study. Dynamic muscle strength was assessed by one-repetition maximum (1-RM) tests. Functional performance was assessed by the Timed Up and Go (TUG), in 30-s test a chair stand and arm curl using a 2-kg dumbbell and balance test, handgrip strength and a sit-and-reach flexibility test. Quality of life (SF-36) and fatigue were also measured.ResultsThe SLE patients showed significantly lower dynamic muscle strength in all exercises (leg press 25.63%, leg extension 11.19%, leg curl 15.71%, chest press 18.33%, lat pulldown 13.56%, 1-RM total load 18.12%, P < 0.001-0.02) compared to the controls. The SLE patients also had lower functional performance, greater fatigue and poorer quality of life. In addition, fatigue, SF-36 and functional performance accounted for 52% of the variance in dynamic muscle strength in the SLE patients.ConclusionsPremenopausal SLE patients with low disease activity showed lower dynamic muscle strength, along with increased fatigue, reduced functional performance, and poorer quality of life when compared to matched controls.

Understanding the individual responsiveness to resistance training periodization

This study was designed to compare the effects of linear periodization (LP) and undulating periodization (UP) on functional capacity, neuromuscular function, body composition, and cytokines in elderly sedentary women. We also aimed to identify the presence of high responders (HR), medium responders (MR), and low responders (LR) for irisin, interleukin-1 beta (IL-1β), toll-like receptor-4 (TLR-4), and brain-derived neurotrophic factor (BDNF) to resistance training (RT). Forty-nine elderly women were assigned to a control group, LP, and UP scheme. Functional capacity, body composition, maximal strength, irisin, TLR-4, BDNF, and IL-1β were evaluated. Both periodization models were effective in improving 45° leg press 1RM, chair-stand, arm curl, and time-up and go tests, with no significant differences in body composition and cytokines. Furthermore, HR, MR, and LR were identified for irisin, IL-1β, TLR-4, and BDNF, with differences between groups and moments. This study provides evidence that both periodization models were effective in improving functional capacity and neuromuscular function, with no effect on body composition and cytokines (probably as a consequence of the different responsiveness). Furthermore, for the first time, HR, MR, and LR were identified for irisin, IL1-β, TLR-4, and BDNF in response to RT.

Three consecutive days of interval runs to exhaustion affects lymphocyte subset apoptosis and migration.

This investigation assessed the lymphocyte subset response to three days of intermittent run exercise to exhaustion. Twelve healthy college-aged males (n = 8) and females (n = 4) (age = 26 ± 4 years; height = 170.2 ± 10 cm; body mass = 75 ± 18 kg) completed an exertion test (maximal running speed and VO2max) and later performed three consecutive days of an intermittent run protocol to exhaustion (30 sec at maximal running speed and 30 sec at half of the maximal running speed). Blood was collected before exercise (PRE) and immediately following the treadmill bout (POST) each day. When the absolute change from baseline was evaluated (i. e., Δ baseline), a significant change in CD4+ and CD8+ for CX3CR1 cells was observed by completion of the third day. Significant changes in both apoptosis and migration were observed following two consecutive days in CD19+ lymphocytes, and the influence of apoptosis persisted following the third day. Given these lymphocyte responses, it is recommended that a rest day be incorporated following two consecutive days of a high-intensity intermittent run program to minimize immune cell modulations and reduce potential susceptibility.

Women with metabolic syndrome present different autonomic modulation and blood pressure response to an acute resistance exercise session compared with women without metabolic syndrome

Metabolic syndrome (MetS) is a cluster of risk factors in individuals with high risk of diabetes and heart disease. Resistance training (RT) has been proposed to be a safe, effective and worthwhile method for the prevention and treatment of metabolic and cardiovascular diseases. However, no study has analysed the acute response of blood pressure (BP) and autonomic control of heart rate (HR) after a RT session in female patients with MetS. The aim of the present study was to analyse the response of laboratory assessed and ambulatory BP and cardiac autonomic modulation after a RT session in women with MetS. Nine women without MetS (35·0 ± 6·7 years) and 10 women with MetS (34·1 ± 9·4 years) completed one experimental exercise session and a control session. Laboratory BP, heart rate variability (HRV) and ambulatory BP of each subject were measured at rest, over 60 min, and for 24 h after the end of the sessions, respectively. There was a significant reduction in systolic blood pressure (SBP), night time diastolic blood pressure (DBP) and mean blood pressure (MBP) only for women with MetS, for all periods after the RT session when compared with the control session (P<0·05). Significantly lower laboratory values of SBP and DBP (10, 30 and 40 min postexercise) and MBP (10, 40 and 50 min postexercise) were observed in women with MetS (P<0·05). Patients with MetS exhibited significant lower basal HRV and a lower autonomic responsiveness during the 60 min of acute recovery. These results confirmed that an acute session of resistance exercise induced a lower BP during day time and sleeping hours in women with MetS that may offer a cardio‐protective effect. Women with MetS exhibited an impaired autonomic modulation at rest and a lower acute autonomic responsiveness to a RT session. The dissociation between BP and HRV responses suggests that other factors than autonomic control could be involved in the hypotensive effect of a RT session in MetS patients.