High Resistance Training Research Articles

Effects of 6 Weeks of Traditional Resistance Training or High Intensity Interval Resistance Training on Body Composition, Aerobic Power and Strength in Healthy Young Subjects: A Randomized Parallel Trial.

Consistent practice of physical activity has well known positive effects on general health; however, time for exercise remains one major barrier for many. An acute bout of high intensity interval resistance training (HIIRT) increases acute resting energy expenditure (REE) and decreases respiratory ratio (RR), suggesting its potential role on weight loss and increased fatty acid oxidation. The aim of this study was to test the long-term effect of HIIRT on body composition, lipid profile and muscle strength using a randomized parallel trial. Twenty healthy young adults (22.15 ± 1.95 years) were randomized to perform either a HIIRT (N = 11) protocol, consisting of three sets of 6 repetitions at 6 repetition maximum (RM) and then 20 seconds of rest between repetitions until exhaustion repeated for 3 times with 2′30″ rest between sets or a traditional training (TRT, N = 9) protocol of 3 sets of 15 reps with 75 sec of rest between sets. Body composition, resting energy metabolism, aerobic capacity, muscle strength and blood measurements were taken before and after 8 weeks of training. Both protocols enhanced muscle strength, but only HIIRT improved endurance strength performance (+22.07%, p < 0.05) and lean body mass (+2.82%, p < 0.05). REE and RR were unaltered as lipid profile. HIIRT represents a valid training method to improve muscle strength and mass, but its role on body weight control was not confirmed.

High and low-load resistance training produce similar effects on bone mineral density of middle-aged and older people: A systematic review with meta-analysis of randomized clinical trials.

To compare the effects of high-load (≥ 70 of 1RM) and low-load (< 70 of 1RM) resistance training (RT) on femoral neck and lumbar spine bone mineral density (BMD) in middle-aged and older people. Systematic review with meta-analysis. English language searches of the electronic databases PubMed/Medline, Scopus and Web of Science. (i) older or middle-aged (≥ 45years old) participants of both sexes with or without comorbidities, (ii) studies that compared high-load (≥70% 1 RM) versus low-load (<70% 1RM) RT, (iii) studies that examined femoral neck or lumbar spine BMD. From 1052 studies found, six were included in qualitative and quantitative analysis. The meta-analysis revealed no difference between groups for femoral neck (weighted mean difference [MD] and 95% confidence interval (CI)=0.00g/cm2 [95% CI, -0.01 to 0.01]; P=0.63) and lumbar spine (MD=0.01g/cm2 [95% CI, -0.00 to 0.02]; P=0.12) BDM. There was a substantial heterogeneity for femoral neck (I2=47%; P=0.07) and lumbar spine (I2=59%; P=0.02). Subgroup analysis revealed a significant effect of high-load RT on femoral neck BMD when participants presented normal BMD values (MD=0.01g/cm2 [95% CI, -0.00 to 0.02]; P=0.04) and on interventions lasting up to 6months (MD=0.01g/cm2 [95% CI, -0.00 to 0.02]; P=0.03). Both high- and low-load RT have similar effects on femoral neck and lumbar spine BMD in aging people.

Resistance training affects the hemodynamic parameters of hypertensive and normotensive women differently, and regardless of performance improvement

Background/ObjectiveAlthough the positive effects of resistance training (RT) on strength and functional capacity have been well evidenced in the scientific literature, the effects of RT on blood pressure and the relationship of these responses with performance improvement are not yet well established. This study aimed to analyze the effects of three and six months of RT on the hemodynamic parameters and functional capacity of hypertensive and normotensive women. MethodSixteen hypertensive and 15 normotensive elderly women participated in a RT protocol designed to increase muscle strength and hypertrophy, lasting six months, twice a week. ResultsSystolic blood pressure (SBP) had a reduction at six months only in hypertensive patients, while diastolic blood pressure (DBP) decreased at six months of intervention in both groups (p < 0.05). SBP showed differences between the groups in the pretest (p < 0.05), but not at three and six months of intervention (p > 0.05). Heart rate (HR) was reduced at three months in hypertensive patients, and at six months in the normotensive (p < 0.05). The strength and functional mobility of both hypertensive and normotensive individuals significantly increased at three and six months of intervention (p < 0.05). Hypertensive women showed increased strength at all moments, while normotensive ones showed improvement only at six months. ConclusionModerate to high intensity RT improves the hemodynamic parameters of hypertensive and normotensive women differently, and independently of strength gain and functional capacity improvement.

Comparative Study between Efficacy of Circuit Training and Interval Training in Improving Exercise Capacity among Chronic Kidney Disease Patients

Introduction: Exercise has several benefits in general population in reducing risk of cardiovascular mortality. Aerobic, resistance and combined exercise are several forms of exercises suggested in CKD to improve quality of life. Circuit training and interval training are two important forms of high intensity aerobic resistance training. There is a limited data that compares these two forms of exercise and their benefits in CKD. Hence this study was designed to find and compare the effectiveness of circuit training and interval training in improving exercise capacity amongst CKD. Materials and Method: This was an intervention study. Patients aged between 36-71 years with CKD stage 2-5, who were hemodynamically stable, who could perform activities and not having associated co morbid conditions were included. Those with chronic heart failure and co morbid conditions were excluded. 82 patients were recruited, with 41 in each of circuit training and interval training group. The intervention (circuit based and interval based) lasted for 8 weeks in total, with exercise sessions lasting for 50-55 minutes at a frequency of 3 sessions per week. The progression of intensity, frequency and duration was monitored and controlled by Borg’s perceived exertion scale applied for resistance exercise. 6 minutes walk test prior and after exercise at baseline and after 8 weeks was recorded along with vitals. Results and Discussion: 120 patients were screened from February 2016 through January 2017 for eligibility to participate in this study, patients assessed for eligibility to participate, 38 individuals were excluded because they did not meet inclusion criteria or declined to participate in the study after the initial screening according to inclusion criteria selected the sample 41 patient each has selected for each group rest of them excluded from the study. Conducted study for total duration of 1 year, each patient had trained for 8 weeks. 2 weeks supervised and 6 weeks home based. All were performed well during training period. Conclusion: Baseline characteristics were similar and both circuit and interval exercise intervention showed improvement in 6 minutes walk test.

Rehabilitation with the aid of blood flow restriction training

For various reasons many patient groups are unable to perform high-intensity strength training. Is the application of low-intensity strength training under blood flow restriction (BFR) an alternative to high-intensity training for patients? Overview and summary of possible applications of BFR training in patients with osteoarthritis of the knee joint, after surgery and in patients with reduced performance. Possible contraindications and application recommendations for clinical practice based on the currently available literature are shown. In patients with arthritic joint complaints, muscular hypertrophy and strength improvement were achieved by low-intensity exercise with the aid of BFR. In the postoperative treatment after knee arthroscopy and anterior cruciate ligament reconstruction, BFR can be used to reduce atrophy. The effectiveness of low-intensity BFR training is lower than for classical high-resistance training; however, it may be used as additional training method in rehabilitation programs.

Comparison of High Versus Low Eccentric-Based Resistance Training Frequencies on Short-Term Muscle Function Adaptations.

Crane, JS, Thompson, BJ, Harrell, DC, Bressel, E, and Heath, EM. Comparison of high versus low eccentric-based resistance training frequencies on short-term muscle function adaptations. J Strength Cond Res 36(2): 332-339, 2022-Eccentric resistance training is beneficial for improving a number of performance and health metrics. However, the recommendations on eccentric training frequency have not been established. This study investigates the effects of volume-matched resistance training frequency comparing 1 vs. 3 training days per week of isokinetic multiple-joint eccentric training on strength and lower-body function adaptations during a 4-week training period. Thirty subjects were assigned to either 3 days per week (high-frequency [HF]) or 1 day per week (low-frequency [LF]) training conditions for 4 weeks. An eccentric dynamometer was used for the training and testing. Eccentric strength and vertical jump (VJ) measures were taken at Pre, Mid (2 weeks), and Post (4 weeks) intervention. Soreness (visual analog scale [VAS]) and rate of perceived exertion (RPE) were taken throughout the training period. There was no group × trial interaction for eccentric strength (p = 0.06) or VJ (p = 0.87). For eccentric strength, all trials were significantly different (p < 0.001) from each other. For VJ, there was a main effect for trial such that VJ increased from Pre to Post (p < 0.001) and Mid to Post (p < 0.01). High frequency reported lower RPE (p < 0.01) and soreness (p = 0.04) compared with LF. Both HF and LF protocols elicited large (36.8 and 27.4% strength increases, respectively) and rapid neuromuscular adaptations for improved strength. Eccentric-based workload may be dispersed across a given period to allow for reduced soreness and perceived exertion levels without compromising neuromuscular adaptations. Some eccentric training transfer to functional (VJ) task may also be observed, independent of training frequency.

Muscle Sentry® Has no Effect on Total Work Performed and Estimated MVO2 after High Intensity Short Duration Resistance Training

Muscle Sentry® Has no Effect on Total Work Performed and Estimated MVO2 after High Intensity Short Duration Resistance Training

Impact of High-Intensity Interval Training and Circuit Resistance Training protocols on Serum Levels of Interleukin-10, Lipid Profile, Body Composition and Insulin Resistance Index in Overweight Male Adolescents

Background: High intensity interval training (HIIT) and circuit resistance training (CRT) have been introduced as useful strategies for weight management in overweight and obese individuals. However, little is known about their effects on inducing anti-inflammatory cytokine response, and improving body composition and metabolic profile (lipid profile and insulin resistance index (HOMA-IR)) in overweight adolescents. Objectives: This study aimed at examining the effects of HIIT and CRT on serum levels of interleukin-10 (IL-10), lipid profile, body composition and insulin resistance index (HOMA-IR) in overweight male adolescents. Methods: Twenty overweight male adolescents were divided into two groups of HIIT and CRT. The blood samples were drawn from all participants before the beginning of exercise protocols and after one day the last session of the exercise protocols. Results: Following 6 weeks of both HIIT and CRT protocols, serum levels of IL-10 increased insignificantly in both groups (P > 0.05). However, that of IL-10 showed a much more increase in HIIT group. Furthermore, unlike CRT protocol, six weeks of HIIT improved body composition, lipid profile and HOMA-IR in overweight male adolescents. Conclusions: By this study, it seems that HIIT has more potent impact than CRT on inducing an anti-inflammatory cytokine response. Moreover, HIIT is a more appropriate exercise modality than CRT to improve body composition and metabolic profile (lipid profile and HOMA-IR) in overweight male adolescents.

Hypotensive Effects of High Intensity Resistance Training to Muscle Failure in Hypertensive Postmenopausal Women

PURPOSE: Moderate-intensity Resistance Training (RT) has been recommended for blood pressure (BP) control by the main guidelines. However hypotensive effects of high intensity RT using higher loads to muscle failure in hypertensive patients is little know. Therefore, the aim of the study was to verify the behavior of BP after the session of high intensity resistance training in hypertensive women. METHODS: A randomized crossover design clinical trial was conducted with 10 controlled hypertensive women with age equal to: 58.9±6.8, body mass index equal to: 27.1±3.8. The participants performed two experimental protocols: a control session and RT session with 6 repetition maximum (RM) to muscle failure. The order of execution of the sessions was performed randomly by lot. The sessions of 6RM was performed with three exercises (lat pulldown, barbell bench press and 45° leg press) in three sets to momentary concentric failure. During the control session the participants followed of rest in the laboratory. Systolic blood pressure (SBP), diastolic blood pressure (DBP) were collected pre, immediately post, 1 h post, and 24 h post each protocol. Repeated measures ANOVA were used. RESULTS: The SPB decrease in 1 h (124.3 ± 10.8) and 24 h (126.2 ± 13.6) after the 6RM session to muscle failure when compared to pre (135.7 ± 14.1), (p < 0.05). SBP was higher for 6RM (144.7±16.4) than control (134.2 ± 18.1) immediately after session (p < 0.05). There were no differences for DBP among protocols (p ≥ 0.05). CONCLUSIONS: The RT using higher loads to muscle failure promote SPB hypotension 1 h and 24 h after the session. No DPB changes were observed after the RT protocols. The high intensity resistance training can decrease the SPB acutely and help in control of blood pressure in hypertensive women.

Effects of High Intensity Resistance Training on Cardiac Autonomic Modulation in Hypertensive Women

Individuals with arterial hypertension often have an autonomic nervous system (ANS) imbalance with predominance of sympathetic ANS. This predominance can lead to injury of several organs affecting its functioning. There is evidence that performing high intensity resistance training (RT) with heavier loads and a lower number of repetitions results in lower cardiovascular stress when compared with lighter loads and a higher number of repetitions. However, the effects of different protocols of RT in autonomic modulation are not known specially using nonlinear analyses methods. PURPOSE: Analyze and compare the effects of different protocols of high intensity of effort RT on autonomic cardiac modulation of hypertensive women using nonlinear methods. METHODS: A randomized crossover design clinical trial was conducted with 15 postmenopausal hypertensive women who underwent a control session and two high intensity RT protocols involving 6 and 15 repetition maximum (RM). The nonlinear variables that compose Heart Rate Variability (HRV) were collected pre, immediately post, 1 h post, and 24 h post each protocol. Repeated-measures ANOVA were used. RESULTS: The SD1 indices that represent parasympathetic activity in the system were lower in 15RM protocol immediately after the exercise (9.32±11.40) when compared with 6RM (16.38±13.15) and control (19.39±13.40) (p<0.05). The SD2 indices that represent a global variability in the system also were lower in 15RM protocol especially immediately after (13.84±9.57) the exercise when compared with 6RM (24.19±17.50) and control (29.32±17.41) (p<0.05). For the 6RM protocol no relevant clinical changes were observed. CONCLUSIONS: Performing high intensity RT with lower loads and a higher number of repetitions decreases parasympathetic ANS activity, which may be related to an increased cardiovascular stress. On the other hand, heavier load and lower repetition RT did not have a significant impact upon autonomic modulation when compared to a control session.

Effect of moderate and high-intensity endurance and resistance training on serum concentrations of MSTN and IGF-1 in old male Wistar rats.

Background Skeletal muscle is very sensitive to extracellular and intracellular signaling evoked by contractions from endurance and resistance exercise. The aim of this study was to compare the effects of moderate- and high-intensity endurance and resistance training on the serum myostatin (MSTN) and insulin-like growth factor (IGF-1) levels in older rats. Materials and methods Fifty old Wistar male rats (23 months old) were randomly divided into four experimental and one control groups, including moderate-endurance training (MET) (n = 10), high-intensity endurance training (EHT) (n = 10), moderate-intensity resistance training (MRT) (n = 10), high-intensity resistance training (HRT) (n = 10), and control group (C) (n = 10). Seventy-two hours after the last exercise session, euthanasia of the rats were rendered unconscious and direct blood samples were collected. Serum IGF-1 and MSTN concentration were measured using the enzyme-linked immuno sorbent assay (ELISA) method. The statistical analysis was performed using one-way analysis of variance (ANOVA) test with a significance level of p ≤ 0.05. Results There was a significant reduction in MSTN and an increase in IGF-1 concentrations was observed between IGF-I levels in high and moderate resistance and endurance training. However, no significant difference was observed in MSTN levels between groups. Discussion Therefore, it appears that resistance training, especially HRT, is effective to increase growth mediators among older rats.

Muscular Strength Adaptations and Hormonal Responses After Two Different Multiple-Set Protocols of Resistance Training in Postmenopausal Women.

Nunes, PRP, Barcelos, LC, Oliveira, AA, Furlanetto, R, Martins, FM, Resende, EAMR, and Orsatti, FL. Muscular strength adaptations and hormonal responses after two different multiple-set protocols of resistance training in postmenopausal women. J Strength Cond Res 33(5): 1276-1285, 2019-We studied the effects of 2 different resistance training (RT) multiple-set protocols (3 and 6 sets) on muscle strength and basal hormones concentrations in postmenopausal women (PW). Postmenopausal women were randomly allocated into 3 groups: control (CT, n = 12), low RT volume (LV = 3 sets for each exercise, n = 10), and high RT volume (HV = 6 sets for each exercise, n = 12). The LV and HV groups performed 8 exercises of a total body RT protocol 3 times a week, at 70% of 1 repetition maximum (1RM) for 16 weeks. Muscle strength and basal hormone concentrations were measured before and after RT. Our findings show that 3 sets or 6 sets at 70% of 1RM protocol increased muscular strength similarly after 16 weeks (sum of all exercises, LV: 37.7% and HV: 34.1% vs. CT: 2.1%, p < 0.001). Moreover, the RT volume does not affect basal levels of testosterone (TT) (LV: 0.02%, HV: -0.12%, and CT: 0.006%, p = 0.233), cortisol (C) (LV: 72.4%, HV: 36.8%, and CT: 16.8%, p = 0.892), insulin-like growth factor-1 (LV: 6.7%, HV: 7.3%, and CT: 4.1%, p = 0.802), dehydroepiandrosterone sulfate (LV: 0.1%, HV: -4.5%, and CT: -6.7%, p = 0.885), and TT:C ratio (LV: -0.9%, HV: -1.6%, and CT: -0.4%, p = 0.429). Our results suggest that 3 sets and 6 sets at 70% of 1RM seem to promote similar muscle strength gain. Thus, 3-set RT is a time efficient protocol for strength gain after 16 weeks in PW.

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.

Effects of free weights and machine training on muscular strength in high-functioning older adults.

Resistance training is assumed to be a key player in counteracting the age-related decline of functional capacity as well as the incidence of falls in older adults. Functional training using free weights is presumed to mimic daily activities, but there is a lack of studies comparing free weight training with barbells and machine training in older adults. The purpose of this study was to evaluate the development of muscle strength for high resistance training in high functioning older people for machines as well as free-weights as well as testing the feasibility of free weight training for this target group. Thirty-two fitness trained women and men aged 60 to 86 years (mean: 66.9, SD: ±5.5) participated in this study. Machine exercisers (n = 16; chest press, leg press, upper row, biceps cable curls, triceps cable extension) vs. free weight exercisers (n = 16; squat, bench press, bent-over rowing, biceps curls, lying triceps press) participated twice à week for a total of 26 weeks. They trained the same five muscle groups for three sets with 10 to 12 repetitions at the 10-Repetition-Maximum, followed by 20 min of endurance training over six months. Three measurements (dynamic, isometric strength and endurance) were taken at the beginning, after 10 weeks and again after 26 weeks. Repeated measures MANCOVA analysis revealed significant increases in the free weights training group (FWT) as well as in the machine training group (MT) over the period of 6 months. However, only for leg strength (113 vs. 44%) and triceps (89.0 vs. 28.3%) the free-weights group exhibited significant differences for the percentage increase over a period of 26 weeks compared to the machine group. A detraining period revealed the decline of the dynamic strength without training. The analysis of the follow-up questionnaire resulted in higher demands for safety, but also higher values for fun, motivation, future, and benefit for daily life for the FWT group compared to the MT group indicating an overall better evaluation of their training specific regime. Our results demonstrate that especially free-weight training has benefits in improving leg and triceps strength as well as in the subjective perception in older adults. Nevertheless, our results do not overall indicate that free-weight training is superior to machine training for increasing strength.

Individual Muscle Hypertrophy and Strength Responses to High vs. Low Resistance Training Frequencies.

Damas, F, Barcelos, C, Nóbrega, SR, Ugrinowitsch, C, Lixandrão, ME, Santos, LMEd, Conceição, MS, Vechin, FC, and Libardi, CA. Individual muscle hypertrophy and strength responses to high vs. low resistance training frequencies. J Strength Cond Res 33(4): 897-901, 2019-The aim of this short communication was to compare the individual muscle mass and strength gains with high (HF) vs. low (LF) resistance training (RT) frequencies using data from our previous study. We used a within-subject design in which 20 subjects had one leg randomly assigned to HF (5× per week) and the other to LF (2 or 3× per week). Muscle cross-sectional area and 1 repetition maximum were assessed at baseline and after 8 weeks of RT. HF showed a higher 8-week accumulated total training volume (TTV) (p < 0.0001) compared with LF. Muscle cross-sectional area and 1 repetition maximum values increased significantly and similarly for HF and LF protocols (p > 0.05). This short communication highlights that some individuals showed greater muscle mass and strength gains after HF (31.6 and 26.3% of individuals, respectively), other had greater gains with LF (36.8 and 15.8% of individuals, respectively), and even others showed similar responses between HF and LF, regardless of the consequent higher or lower TTV resulted from HF and LF, respectively. Importantly, individual manipulation of RT frequency can improve the intrasubject responsiveness to training, but the effect is limited to each individual's capacity to respond to RT. Finally, individual response to different frequencies and resulted TTV does not necessarily agree between muscle hypertrophy and strength gains.

The short- and long-term effects of resistance training with different stability requirements.

The aim of this study was to assess the short- and long-term effects of resistance training (RT) with different stability requirements. Fifty-nine men underwent a 3-week familiarization period followed by a 7-week training period. During familiarization, all participants trained four sessions of squats with a Smith machine, free weights and free weights standing on a wobble board. After week-3, participants were randomized into a low (Smith machine), medium (Free-weight) or high (Wobble board) stability RT program, and Control group. All participants were tested pre-, after week-3 and post-intervention. Ten repetition maximum (10RM), rate of force development (RFD), electromyography (EMG) and maximum voluntary isometric contraction (MVIC) were tested in all three squat conditions in addition to countermovement jump (CMJ) on stable and unstable surfaces, and muscle thickness. After familiarization, greater 10RM loads (21.8–27.3%), MVIC (7.4–13.5%), RFD (29.7–43.8%) and CMJ (4.9–8.5%) were observed in all conditions. Between week 3 and 10, the Free-weight and Wobble board groups similarly improved 10RM in all conditions. Smith machine group demonstrated greater improvement in the trained exercise than the medium and high stability exercises. All training groups showed similar improvement in muscle thickness, RFD and MVIC. There was no CMJ improvement on the stable surface, but the Wobble board group demonstrated significantly greater improvement on the unstable surface. In conclusion, low, medium or high stability RT resulted in similar improvements in trained and non-trained testing conditions except for greater CMJ on the unstable surface in the Wobble group. Greater 10RM strength in trained than non-trained exercise was only observed in low stability group. Familiarization was associated with substantial improvements in 10RM and CMJ, with greater improvement associated with higher stability requirements. These findings suggest that high stability can increase strength, muscle thickness and explosive measurements similar to training with lower stability.

Efectos agudos del ejercicio resistido en la lipemia postprandial de mujeres postmenopáusicas con sobrepeso

Introducción. La magnitud de la lipemia postprandial es un indicador de riesgo cardiovascular, en especial en mujeres con actividad hormonal reducida. Los ejercicios resistidos (ER) podrían ser un factor que influencie las concentraciones de lípidos después de consumir alimentos.Objetivo. Determinar los efectos agudos sobre la lipemia postprandial de mujeres postmenopáusicas que tiene la realización de sesiones de ER de alto y bajo volumen, en comparación a un grupo control.Materiales y métodos. Después de una evaluación inicial (antropometría, perfil lipídico y fitness muscular), 32 mujeres fueron divididas aleatoriamente en tres grupos: uno con ER de alto volumen (n=11), otro con ER de bajo volumen (n=11) y un grupo control sin ER (n=10). 12 horas después de los ejercicios se suministró un compuesto nutricional hiperlipídico y se analizó la lipemia postprandial cada hora durante 5 horas.Resultados. Los diferentes volúmenes de ER no redujeron de manera importante los marcadores lipémicos (colesterol total, triglicéridos, LDL y VLDL) (p&gt;0.05) ni aumentaron las concentraciones plasmáticas de HDL (p&gt;0.05).Conclusiones. Las sesiones de ER no afectaron los marcadores lipémicos postprandiales, aunque sí mostraron resultados clínicos relevantes en los grupos experimentales (reducción de LDL-VLDL y aumento de HDL en momentos específicos).

Association of type and intensity of physical activity with plasma biomarkers of inflammation and insulin response.

Several biological mechanisms linking physical activity with cancer have been proposed. However, the influence of specific components of physical activity (volume, type and intensity), and their interaction with adiposity and diet, on cancer-related biomarkers remain unclear. We used cross-sectional data on 7,219 men in the Health Professionals Follow-up Study (1992-1994) with C-reactive protein (CRP), interleukin-6 (IL6), tumor necrosis factor alpha receptor 2 (TNFαR2), adiponectin, C-peptide and triglycerides/high-density lipoprotein cholesterol ratio (TG/HDL). Details on physical activity, diet and adiposity were assessed by questionnaires. We used multivariable-adjusted linear regression analyses to estimate relative concentrations of biomarkers by physical activity. Total physical activity was favorably associated with all biomarkers in a fairly linear manner. Comparing the highest (63+ metabolic equivalent (MET)-hr/week) to the lowest (0-8.9 MET-hr/week) physical activity groups, the percent relative difference in concentration of biomarkers was -31% for CRP, -22% for IL6, -8% for TNFαR2, +9% for adiponectin, -22% for C-peptide, and -20% for TG/HDL. These differences were modestly attenuated after adjustment for adiposity. For the same total MET-hours of physical activity, the association was stronger for men engaging in both aerobic and resistance exercises compared to those engaging in aerobic only. However, no difference was found between those engaging in vigorous activities (≥20% of total MET-hours) compared to those who did smaller amount of vigorous activities. Physical activity showed similar associations for these biomarkers regardless of adiposity and dietary pattern. In conclusion, high physical activity, preferably aerobic plus resistance training, was associated with favorable cancer-related biomarkers.

Once a Week Resistance Training Improves Muscular Strength in Breast Cancer Survivors: A Randomized Controlled Trial.

Background: Exercise has been shown to reduce adverse outcomes related to breast cancer. However, the rate of adherence to physical exercise is very low among breast cancer survivors (BCS). This study investigated the effects of high supervision ratio resistance training (RT), once a week for 8 weeks, on changes in body composition and muscular strength in BCS. Methods: Twenty-five female BCS undergoing hormone therapy were randomized into resistance training group (TG, n = 12) or control (CG, n = 13) group. The TG performed 8 weeks of supervised RT, with 1 trainer per volunteer, once a week. Body composition was evaluated by dual-energy X-ray absorptiometry, and muscle strength was evaluated by 10 repetition maximum (10 RM) for leg press (45°) and bench press exercises. A 1-way analysis of variance was used to compare within-group effects at pre- and post-intervention. An analysis of covariance test was used to compare post-intervention values, using pre-intervention measures as covariates. The effect size (ES) was calculated by Cohen’s d. Results: The TG improved muscle strength in 10 RM leg press (45°; Δ 33.75 ± 11.51 kg, P = .02; ES = 0.96) and bench press (Δ 4.08 ± 1.83 kg, P = .01; ES = 1.15). Adherence to training was more than 99%. Changes in body composition were not detected. There were no changes in the CG for any assessment. Conclusion: Once-weekly supervised RT could be an alternative to increase the adherence to exercise and improve muscular strength in BCS.

Effect of Curcumin and Physical Training on the Brain and Motor Performance of Rats with Cerebral Ischemia

Brain ischemia is the second most deadly disease in the world and it has already been proven that mild and moderate physical exercises minimize the deleterious effects of this disease on the brain. Curcumin has also been considered a neuroprotective substance. Therefore, the goal of this study was to evaluate the effects of high-resistance training and curcumin on the brain and motor performance of rats with cerebral ischemia using a model of bilateral common carotid artery occlusion. Functional tests were performed to analyze rats' motor performance, namely parallel bar test and misstep test. For nerve tissue analysis, Nissl staining and neuronal counting were performed in the cerebral cortex, striatum and hippocampus of the brains. Two protocols of high-intensity physical training were performed for six weeks, five days a week, from 20 to 40 min. The results demonstrated that there were significant differences in the parallel bar test and misstep test regarding the number of errors committed by the trained animals in comparison to the sedentary ones and the group that received curcumin. With respect to the number of neurons in the cortex and striatum, a lower neuronal density was observed in the trained animals. Thus, the animals of the sedentary group and the group that received curcumin exhibited better motor performance and higher neuronal density in the areas assessed, demonstrating that high-intensity physical exercise increased brain injury and worsened animals' motor performance.