Comparison between multiple sets and half-pyramid resistance exercise bouts for muscle damage profile

The present study compared the changes in markers of muscle damage after bouts of resistance exercise employing the Multiple-sets (MS) and Half-pyramid (HP) training systems. Ten healthy men (26.1 +/- 6.3 years), who had been involved in regular resistance training, performed MS and HP bouts, 14 days apart, in a randomised, counter-balanced manner. For the MS bout, participants performed three sets of maximum repetitions at 75%-1RM (i.e. 75% of a One Repetition Maximum) for the three exercises, starting with the bench press, followed by pec deck and decline bench press. For the HP bout, the participants performed three sets of maximum repetitions with 67%-1RM, 74%-1RM and 80%-1RM for the first, second and third sets, respectively, for the same three exercise sequences as the MS bout. The total volume of load lifted was equated between both bouts. Muscle soreness, plasma creatine kinase (CK) activity, myoglobin (Mb) and C-reactive protein (CRP) concentrations were assessed before and for three days after each exercise bout, and the changes over time were compared between MS and HP using two-way repeated measures ANOVA. Muscle soreness developed significantly (P<0.01) after both bouts, but no significant difference was observed between MS and HP. Plasma CK activity and Mb concentration increased significantly (P<0.01) without significant differences between bouts, and CRP concentration did not change significantly after either bout. These results suggest that the muscle damage profile is similar for MS and HP, probably due to the similar total volume of load lifted.

Predicting Growth of Panicum maximum: An Adaptation of the CROPGRO-Perennial Forage Model

Warm-season grasses are economically important for cattle production in tropical regions and tools to aid in management and research on these forages would be highly beneficial both in research and the industry. This research was conducted to adapt the CROPGRO-Perennial Forage model to simulate growth of the tropical species guineagrass (Panicum maximum Jacq. cv. 'Tanzania') and to describe model adaptation for this species. To develop the CROPGRO parameters for this species, we began with values and relationships reported in the literature. Some parameters and relationships were calibrated by comparison with observed growth, development, dry matter accumulation, and partitioning during a 17-mo experiment with Tanzania guineagrass in Piracicaba, SP, Brazil. Compared with starting parameters for palisadegrass [Brachiaria brizantha (A. Rich.) Stapf. cv. 'Xaraes'], dormancy effects of the perennial forage model had to be minimized, partitioning to storage tissue or root decreased, and partitioning to leaf and stem increased to provide for more leaf and stem growth and less root. Parameters affecting specific leaf area and senescence of plant tissues were improved. After these changes were made to the model, biomass accumulation was better simulated, mean predicted herbage yield was 6576 kg ha(-1), averaged across 11 regrowth cycles of 35 (summer) or 63 d (winter), with a RMSE of 494 kg ha(-1) (Willmott's index of agreement d = 0.985, simulated/observed ratio = 1.014). The model also gave good predictions against an independent data set, with similar RMSE, ratio, and d. The results of the adaptation suggest that the CROPGRO model is an efficient tool to integrate physiological aspects of guineagrass and can be used to simulate growth.

Physiological responses and rate of perceived exertion in Brazilian jiu-jitsu athletes

In this study, the physiological responses and rate of perceived exertion in Brazilian jiu-jitsu fighters submitted to a combat simulation were investigated. Venous blood samples and heart rate were taken from twelve male Brazilian jiu-jitsu athletes (27.1+/-2.7 yrs, 75.4+/-8.8 kg, 174.9+/-4.4 cm, 9.2+/-2.4% fat), at rest, after a warm-up (ten minutes), immediately after the fight simulation (seven minutes) and after recovery (fourteen minutes). After the combat the rate of perceived exertion was collected. The combat of the Brazilian jiu-jitsu fighters did not change blood concentrations of glucose, triglycerides, total cholesterol, low density lipoprotein and very low density lipoprotein, ureia and ammonia. However, blood levels of high density lipoprotein were significantly higher post-fight (before: 43.0+/-6.9 mg/dL, after: 45.1+/-8.0 mg/dL) and stayed at high levels during the recovery period (43.6+/-8.1 mg/dL) compared to the rest values (40.0+/-6.6 mg/dL). The fight did not cause changes in the concentrations of the cell damage markers of creatine kinase, aspartate aminotransferase and creatinine. However, blood concentrations of the alanine aminotransferase (before: 16.1+/-7.1 U/L, after: 18.6+/-7.1 U/L) and lactate dehydrogenase (before: 491.5+/-177.6 U/L, after: 542.6+/-141.4 U/L) enzymes were elevated after the fight. Heart rate (before: 122+/-25 bpm, after: 165+/-17 bpm) and lactate (before: 2.5+/-1.2 mmol/L, after: 11.9+/-5.8 mmol/L) increased significantly with the completion of combat. Despite this, the athletes rated the fight as being light or somewhat hard (12+/-2). These results showed that muscle glycogen is not the only substrate used in Brazilian jiu-jitsu fights, since there are indications of activation of the glycolytic, lipolytic and proteolytic pathways. Furthermore, the athletes rated the combats as being light or somewhat hard although muscle damage markers were generated.

Chronic Conventional resistance exercise reduces blood pressure in stage 1 Hypertensive men

Moraes, MR, Bacurau, RFP, Casarini, DE, Jara, ZP, Ronchi, FA, Almeida, SS, Higa, EMS, Pudo, MA, Rosa, TS, Haro, AS, Barros, CC, Pesquero, JB, Wurtele, M, and Araujo, RC. Chronic conventional resistance exercise reduces blood pressure in stage 1 hypertensive men. J Strength Cond Res 26(4): 1122-1129, 2012-To investigate the antihypertensive effects of conventional resistance exercise (RE) on the blood pressure (BP) of hypertensive subjects, 15 middle-aged (46 +/- 3 years) hypertensive volunteers, deprived of antihypertensive medication (reaching 153 +/- 6/93 +/- 2 mmHg systolic/diastolic BP after a 6-week medication washout period) were submitted to a 12-week conventional RE training program (3 sets of 12 repetitions at 60% 1 repetition maximum, 3 times a week on nonconsecutive days). Blood pressure was measured in all phases of the study (washout, training, detraining). Additionally, the plasma levels of several vasodilators or vasoconstrictors that potentially could be involved with the effects of RE on BP were evaluated pre- and posttraining. Conventional RE significantly reduced systolic, diastolic, and mean BP, respectively, by an average of 16 (p < 0.001), 12 (p < 0.01), and 13 mm Hg (p < 0.01) to prehypertensive values. There were no significant changes of vasoactive factors from the kallikrein-kinin or renin-angiotensin systems. After the RE training program, the BP values remained stable during a 4-week detraining period. Taken together, this study shows for the first time that conventional moderate-intensity RE alone is able to reduce the BP of stage 1 hypertensive subjects free of antihypertensive medication. Moreover, the benefits of BP reduction achieved with RE training remained unchanged for up to 4 weeks without exercise.

Sexual abuse victimisation and perpetration in a cohort of men living with HIV/AIDS who have sex with women from Sao Paulo, Brazil

Sexual abuse leads to physical harm and devastating psychosocial consequences. It increases risk of HIV transmission and is associated with risky behaviour. Little is known about sexual abuse victimisation (SAV) and perpetration (SAP) among HIV-positive men who have sex with women (MSW). We investigated self-reported SAV and SAP among 242 Brazilian MSW selected at HIV care centres. Patients were questioned about sociodemographic data, mode of HIV acquisition, sexual practices, drug use and history of SAV or SAP. Prevalence of outcomes was estimated and risk factors for SAP investigated by logistic regression. Fifty-eight (24.1%) interviewees reported SAV. Of patients abused before 15 years of age, 64.3% reported events before the age of ten. Aggressors included relatives, friends and teachers. Among those victimised after 15 years old, 57.7% described events before 17 and 38.5% had acquainted aggressors. Fourteen (5.8%) interviewees reported SAP and most knew their victims. Sexual abuse perpetration was associated with lower schooling, marital status, illicit drug use and self-reported SAV. Sexual abuse was frequently reported by MSW from this cohort. Identifying predictors of violence and addressing SAV and SAP in comprehensive HIV care may help reduce violent behaviour, psychological distress and contribute to maximise benefits of preventive and care interventions.

The effects of a water-based exercise program on strength and functionality of older adults

Objective: To analyze the effects of a water-based exercise program on peak torque (PT) and rate of torque development (RTD) during maximal voluntary ballistic isometric contractions of the lower limb muscles and the performance of a number of functional tests in the elderly. Method: Thirty-seven elderly were randomly assigned to water-based training (3 d/wk for 12 wk) or a control group. Extensor and flexor PT and RTD of the ankle, knee, and hip joints and functional tests were evaluated before and after training. Results: PT increased after training for the hip flexors (18%) and extensors (40%) and the plantar-flexor (42%) muscles in the water-based group. RTD increased after training for the hip-extensor (10%), knee-extensor (11%), and ankle plantar-flexor (27%) muscles in the water-based group. Functional tests also improved after training in the water-based group (p < .05). Conclusion: The water-based program improved PT and RTD and functional performance in the elderly.

An experimental model for resistance exercise in rodents

This study aimed to develop an equipment and system of resistance exercise (RE), based on squat-type exercise for rodents, with control of training variables. We developed an operant conditioning system composed of sound, light and feeding devices that allowed optimized RE performance by the animal. With this system, it is not necessary to impose fasting or electric shock for the animal to perform the task proposed (muscle contraction). Furthermore, it is possible to perform muscle function tests in vivo within the context of the exercise proposed and control variables such as intensity, volume (sets and repetitions), and exercise session length, rest interval between sets and repetitions, and concentric strength. Based on the experiments conducted, we demonstrated that the model proposed is able to perform more specific control of other RE variables, especially rest interval between sets and repetitions, and encourages the animal to exercise through short-term energy restriction and "disturbing" stimulus that do not promote alterations in body weight. Therefore, despite experimental limitations, we believe that this RE apparatus is closer to the physiological context observed in humans.

Manipulation effects of prior exercise intensity feedback by the Borg scale during open-loop cycling

Objective To verify the effects of exercise intensity deception by the Borg scale on the ratings of perceived exertion (RPE), heart rate (HR) and performance responses during a constant power output open-loop exercise. Methods Eight healthy men underwent a maximal incremental test on a cycle ergometer to identify the peak power output (PPO) and heart rate deflection point (HRDP). Subsequently, they performed a constant power output trial to exhaustion set at the HRDP intensity, in deception (DEC) and informed (INF) conditions: DEC-subjects were told that they would be cycling at an intensity corresponding to two categories below the RPE quantified at the HRDP; INF-subjects were told that they would cycle at the exact intensity corresponding to the RPE quantified at the HRDP. Results The PPO and power output at the HRDP obtained in maximal incremental tests were 247.5 +/- 32.1 W and 208.1 +/- 27.1 W, respectively. No significant difference in the time to exhaustion was found between DEC (525 +/- 244 s) or INF (499 +/- 224 s) trials. The slope and the first and second measurements of the RPE and HR parameters showed no significant difference between trials. Conclusions Psychophysiological variables such as RPE and HR as well as performance were not affected when exercise intensity was deceptively manipulated via RPE scores. This may suggest that unaltered RPE during exercise is a regulator of performance in this open-loop exercise.

Is there a relationship between the total volume of load lifted in bench press exercise and the rating of perceived exertion?

Aim. The purpose of the study was to investigate the relationship between the total volume of load lifted (TVLL) and the rating of perceived exertion (RPE) measures during different resistance training (RT) schemes using the bench press exercise. Methods. The present study was divided into two experiments. In the first experiment, 18 healthy men performed three different RT schemes: a strength oriented scheme (SS), a muscular endurance oriented scheme (ES) and a hypertrophy oriented scheme (HS). TVLL was calculated for each scheme. Mean-RPE and session-RPE were assessed. In the second experiment, 23 men performed two resistance exercise bouts at different intensities (50 %-1RM and 75%-1RM) with matched TVLL. Mean-RPE and session-RPE were also assessed. Results. SS and HS showed higher TVLL and greater RPE scores as compared to ES (P<0.05). No significant difference was observed between SS and HS. It was verified significant positive correlations between TVLL and session-RPE (SS r=0.63, HS r=0.64, ES r=0.56; P<0.05), and between mean-RPE and TVLL (SS r=0.55, HS r=0.52, ES r=0.47; P<0.05) for all schemes. No differences were observed for mean-RPE, session-RPE and TVLL between the 50%-1RM and 75%1RM. Significant positive relationships between TVLL and session-RPE (50 %-1RM r=0.61, 75 %-1RM r=0.66; p<0.05) and between TVLL and mean-RPE (50 %-1RM r=0.51, 75%1RM r=0.49; P<0.05) were observed. Conclusion. The results of this study have shown that the TVLL in RT influences RPE measures. These findings corroborates the existence of a relationship between total work performed (external training load) and perception of effort (internal training load).

Previous Exercise Training Has a Beneficial Effect on Renal and Cardiovascular Function in a Model of Diabetes

Exercise training (ET) is an important intervention for chronic diseases such as diabetes mellitus (DM). However, it is not known whether previous exercise training intervention alters the physiological and medical complications of these diseases. We investigated the effects of previous ET on the progression of renal disease and cardiovascular autonomic control in rats with streptozotocin (STZ)-induced DM. Male Wistar rats were divided into five groups. All groups were followed for 15 weeks. Trained control and trained diabetic rats underwent 10 weeks of exercise training, whereas previously trained diabetic rats underwent 14 weeks of exercise training. Renal function, proteinuria, renal sympathetic nerve activity (RSNA) and the echocardiographic parameters autonomic modulation and baroreflex sensitivity (BRS) were evaluated. In the previously trained group, the urinary albumin/creatinine ratio was reduced compared with the sedentary diabetic and trained diabetic groups (p < 0.05). Additionally, RSNA was normalized in the trained diabetic and previously trained diabetic animals (p < 0.05). The ejection fraction was increased in the previously trained diabetic animals compared with the diabetic and trained diabetic groups (p < 0.05), and the myocardial performance index was improved in the previously trained diabetic group compared with the diabetic and trained diabetic groups (p < 0.05). In addition, the previously trained rats had improved heart rate variability and BRS in the tachycardic response and bradycardic response in relation to the diabetic group (p < 0.05). This study demonstrates that previous ET improves the functional damage that affects DM. Additionally, our findings suggest that the development of renal and cardiac dysfunction can be minimized by 4 weeks of ET before the induction of DM by STZ.

Creatine but not betaine supplementation increases muscle phosphorylcreatine content and strength performance

We aimed to investigate the role of betaine supplementation on muscle phosphorylcreatine (PCr) content and strength performance in untrained subjects. Additionally, we compared the ergogenic and physiological responses to betaine versus creatine supplementation. Finally, we also tested the possible additive effects of creatine and betaine supplementation. This was a double-blind, randomized, placebo-controlled study. Subjects were assigned to receive betaine (BET; 2 g/day), creatine (CR; 20 g/day), betaine plus creatine (BET + CR; 2 + 20 g/day, respectively) or placebo (PL). At baseline and after 10 days of supplementation, we assessed muscle strength and power, muscle PCr content, and body composition. The CR and BET + CR groups presented greater increase in muscle PCr content than PL ( = 0.004 and = 0.006, respectively). PCr content was comparable between BET versus PL ( = 0.78) and CR versus BET + CR ( = 0.99). CR and BET + CR presented greater muscle power output than PL in the squat exercise following supplementation ( = 0.003 and = 0.041, respectively). Similarly, bench press average power was significantly greater for the CR-supplemented groups. CR and BET + CR groups also showed significant pre- to post-test increase in 1-RM squat and bench press (CR: = 0.027 and < 0.0001; BET + CR: = 0.03 and < 0.0001 for upper- and lower-body assessments, respectively) No significant differences for 1-RM strength and power were observed between BET versus PL and CR versus BET + CR. Body composition did not differ between the groups. In conclusion, we reported that betaine supplementation does not augment muscle PCr content. Furthermore, we showed that betaine supplementation combined or not with creatine supplementation does not affect strength and power performance in untrained subjects.

Health and fitness benefits of a resistance training intervention performed in the workplace

Zavanela, PM, Crewther, BT, Lodo, L, Florindo, AA, Miyabara, EH, and Aoki, MS. Health and fitness benefits of a resistance training intervention performed in the workplace. J Strength Cond Res 26(3): 811-817, 2012-This study examined the effects of a workplace-based resistance training intervention on different health-, fitness-, and work-related measures in untrained men (bus drivers). The subjects were recruited from a bus company and divided into a training (n = 48) and control (n = 48) groups after initial prescreening. The training group performed a 24-week resistance training program, whereas the control group maintained their normal daily activities. Each group was assessed for body composition, blood pressure (BP), pain incidence, muscular endurance, and flexibility before and after the 24-week period. Work absenteeism was also recorded during this period and after a 12-week follow-up phase. In general, no body composition changes were identified in either group. In the training group, a significant reduction in BP and pain incidence, along with improvements in muscle endurance and flexibility were seen after 24 weeks (p < 0.05). There were no changes in these parameters in the control group, and the between-group differences were all significant (p < 0.05). A reduction in worker absenteeism rate was also noted in the training (vs. control) group during both the interventional and follow-up periods (p < 0.05). In conclusion, it was found that a periodized resistance training intervention performed within the workplace improved different aspects of health and fitness in untrained men, thereby potentially providing other work-related benefits. Thus, both employers and employees may benefit from the setup, promotion, and support of a work-based physical activity program involving resistance training.

Aerobic exercise training upregulates skeletal muscle calpain and ubiquitin-proteasome systems in healthy mice

Cunha TF, Moreira JB, Paixao NA, Campos JC, Monteiro AW, Bacurau AV, Bueno CR Jr., Ferreira JC, Brum PC. Aerobic exercise training upregulates skeletal muscle calpain and ubiquitin-proteasome systems in healthy mice. J Appl Physiol 112: 1839-1846, 2012. First published March 29, 2012; doi:10.1152/japplphysiol.00346.2011.-Aerobic exercise training (AET) is an important mechanical stimulus that modulates skeletal muscle protein turnover, leading to structural rearrangement. Since the ubiquitin-proteasome system (UPS) and calpain system are major proteolytic pathways involved in protein turnover, we aimed to investigate the effects of intensity-controlled AET on the skeletal muscle UPS and calpain system and their association to training-induced structural adaptations. Long-lasting effects of AET were studied in C57BL/6J mice after 2 or 8 wk of AET. Plantaris cross-sectional area (CSA) and capillarization were assessed by myosin ATPase staining. mRNA and protein expression levels of main components of the UPS and calpain system were evaluated in plantaris by real-time PCR and Western immunoblotting, respectively. No proteolytic system activation was observed after 2 wk of AET. Eight weeks of AET resulted in improved running capacity, plantaris capillarization, and CSA. Muscle RING finger-1 mRNA expression was increased in 8-wk-trained mice. Accordingly, elevated 26S proteasome activity was observed in the 8-wk-trained group, without accumulation of ubiquitinated or carbonylated proteins. In addition, calpain abundance was increased by 8 wk of AET, whereas no difference was observed in its endogenous inhibitor calpastatin. Taken together, our findings indicate that skeletal muscle enhancements, as evidenced by increased running capacity, plantaris capillarization, and CSA, occurred in spite of the upregulated UPS and calpain system, suggesting that overactivation of skeletal muscle proteolytic systems is not restricted to atrophying states. Our data provide evidence for the contribution of the UPS and calpain system to metabolic turnover of myofibrillar proteins and skeletal muscle adaptations to AET.

AEROBIC OR RESISTANCE EXERCISE IMPROVES PERFORMANCE IN ACTIVITIES OF DAILY LIVING IN ELDERLY WOMEN

The purpose of this randomized non-controlled study was to determine the effect of an aerobic or resistance exercise protocol on performance of activities of daily living in elderly women. The sample was constituted of 41 apparently healthy elderly women aged 60 to 85 years (x: 65.1 +/- 7.9 years) randomly assigned in resistance exercise (n: 22) or aerobic groups (n: 19). The resistance exercise protocol consisted of three sets of eight to 12 repetitions at 60% of one repetition maximum test for the leg press 45 degrees. The aerobic exercise protocol consisted in cycling in a cycle ergometer during 40 minutes at 60% of reserve heart rate. Both protocols were performed three times per week during five weeks. Activities of daily living were estimated by velocity to stand from sitting to standing position (VSitting), velocity to move from supine to standing position (VSupine), velocity to climb stairs (VCS) and velocity to wear sneakers (VWS). Volunteers of aerobic exercise protocol improved significantly the time to perform VWS (19.1%), while the volunteers of resistance exercise protocol improved the capacity to perform VCS (4.3%) and VSupine (8.9%). These results let us conclude that aerobic as well as resistance exercise protocols induced positive effect on activities of daily living, suggesting that both protocols must be associated for an adequate exercise program to improve the functional capacity of elderly people.

Regular and moderate exercise before experimental sepsis reduces the risk of lung and distal organ injury

de Araujo CC, Silva JD, Samary CS, Guimaraes IH, Marques PS, Oliveira GP, do Carmo LGRR, Goldenberg RC, Bakker-Abreu I, Diaz BL, Rocha NN, Capelozzi VL, Pelosi P, Rocco PRM. Regular and moderate exercise before experimental sepsis reduces the risk of lung and distal organ injury. J Appl Physiol 112: 1206-1214, 2012. First published January 19, 2012; doi:10.1152/japplphysiol.01061.2011.-Physical activity modulates inflammation and immune response in both normal and pathologic conditions. We investigated whether regular and moderate exercise before the induction of experimental sepsis reduces the risk of lung and distal organ injury and survival. One hundred twenty-four BALB/c mice were randomly assigned to two groups: sedentary (S) and trained (T). Animals in T group ran on a motorized treadmill, at moderate intensity, 5% grade, 30 min/day, 3 times a week for 8 wk. Cardiac adaptation to exercise was evaluated using echocardiography. Systolic volume and left ventricular mass were increased in T compared with S group. Both T and S groups were further randomized either to sepsis induced by cecal ligation and puncture surgery (CLP) or sham operation (control). After 24 h, lung mechanics and histology, the degree of cell apoptosis in lung, heart, kidney, liver, and small intestine villi, and interleukin (IL)-6, KC (IL-8 murine functional homolog), IL-1 beta, IL-10, and number of cells in bronchoalveolar lavage (BALF) and peritoneal lavage (PLF) fluids as well as plasma were measured. In CLP, T compared with S groups showed: 1) improvement in survival; 2) reduced lung static elastance, alveolar collapse, collagen and elastic fiber content, number of neutrophils in BALF, PLF, and plasma, as well as lung and distal organ cell apoptosis; and 3) increased IL-10 in BALF and plasma, with reduced IL-6, KC, and IL-1 beta in PLF. In conclusion, regular and moderate exercise before the induction of sepsis reduced the risk of lung and distal organ damage, thus increasing survival.