Reduced Handgrip Strength Is Associated with 1 Year-Mortality in Brazilian Frail Nonagenarians and Centenarians.

The aim of the present study was to investigate the association between handgrip strength and mortality in Brazilian frail nonagenarians and centenarians. Eighty-one oldest old were included (mean age [SD]: 94.2 [3.8] years). Data on strength was assessed by handgrip strength. Mortality rate of the participants was evaluated at 1-year follow-up after the functional assessment. A logistic regression analysis was used to assess differences in categories of handgrip strength between groups regarding the mortality rate. Forty-six participants (56.8%) had reduced handgrip strength. After 1 year, there were 16 deaths. Those older adults with a low handgrip strength had higher prevalence (28.3% vs. 8.6%) and increased risk of mortality than those with preserved handgrip strength (Odds ratio=4.4, confidence interval 95% 1.1, 18.4) (p=0.042). Reduced handgrip strength is associated with higher mortality rate at 1-year follow-up in Brazilian frail nonagenarians and centenarians.

Cost-Consequences Analysis Following Different Exercise Interventions in Institutionalized Oldest Old: A Pilot Study of a Randomized Clinical Trial.

OBJECTIVES: to investigate the effects of two different exercise interventions on cost of care, functional capacity, falls occurrence, muscle strength, and executive function in institutionalized oldest old. DESIGN: A pilot study of a randomized clinical trial investigating 12 months of two exercise interventions compared to a usual care group in oldest old residents of a nursing home. SETTING AND PARTICIPANTS: 69 older patients (mean age 89.4 ±5.1 years) completed the full baseline and post intervention measurements. Participants were randomly allocated into multicomponent exercise group (MG, n=23), calisthenics group (CALG, n = 23), and usual care group (UCG, n=23). METHODS: Primary outcome was individual cost of care, and secondary outcomes included different physical and cognitive functioning tests, as well as number of falls. RESULTS: MG reduced the cost of care compared to the pre-intervention period, with the greatest difference from baseline achieved in month 12 [mean change 95% confidence interval (CI)=-330.43 (-527.06, -133.80), P=0.006], while UCG increased this outcome, with the greatest difference from baseline observed in month 12 [mean change (95%CI)=300.00 (170.27, 429.72), P=0.013]. In addition, MG significantly improved SPPB score [mean change (95% CI) = 1.21 (0.55, 1.88), P<0.001], whereas the UCG exhibited a decline in scores [mean change (95% CI) = -1.43 (-1.90, -0.97), P<0.001]. Moreover, MG group demonstrated an improvement in the number of falls [mean change (CI 95%) = -1.0 (-1.73, -0.27), P=0.003], while no significant changes were observed in UCG. Additionally, MG exhibited a significant increase in the handgrip strength (HGS) and leg press strength (P<0.001), while a decrease was observed in UCG (P<0.001). No significant changes were observed in the CALG. CONCLUSIONS AND IMPLICATIONS: a one-year multicomponent exercise intervention reduced the cost of care, improved functional capacity and muscle strength, as well as reduced falls in institutionalized oldest old.

International Exercise Recommendations in Older Adults (ICFSR): Expert Consensus Guidelines.

The human ageing process is universal, ubiquitous and inevitable. Every physiological function is being continuously diminished. There is a range between two distinct phenotypes of ageing, shaped by patterns of living - experiences and behaviours, and in particular by the presence or absence of physical activity (PA) and structured exercise (i.e., a sedentary lifestyle). Ageing and a sedentary lifestyle are associated with declines in muscle function and cardiorespiratory fitness, resulting in an impaired capacity to perform daily activities and maintain independent functioning. However, in the presence of adequate exercise/PA these changes in muscular and aerobic capacity with age are substantially attenuated. Additionally, both structured exercise and overall PA play important roles as preventive strategies for many chronic diseases, including cardiovascular disease, stroke, diabetes, osteoporosis, and obesity; improvement of mobility, mental health, and quality of life; and reduction in mortality, among other benefits. Notably, exercise intervention programmes improve the hallmarks of frailty (low body mass, strength, mobility, PA level, energy) and cognition, thus optimising functional capacity during ageing. In these pathological conditions exercise is used as a therapeutic agent and follows the precepts of identifying the cause of a disease and then using an agent in an evidence-based dose to eliminate or moderate the disease. Prescription of PA/structured exercise should therefore be based on the intended outcome (e.g., primary prevention, improvement in fitness or functional status or disease treatment), and individualised, adjusted and controlled like any other medical treatment. In addition, in line with other therapeutic agents, exercise shows a dose-response effect and can be individualised using different modalities, volumes and/or intensities as appropriate to the health state or medical condition. Importantly, exercise therapy is often directed at several physiological systems simultaneously, rather than targeted to a single outcome as is generally the case with pharmacological approaches to disease management. There are diseases for which exercise is an alternative to pharmacological treatment (such as depression), thus contributing to the goal of deprescribing of potentially inappropriate medications (PIMS). There are other conditions where no effective drug therapy is currently available (such as sarcopenia or dementia), where it may serve a primary role in prevention and treatment. Therefore, this consensus statement provides an evidence-based rationale for using exercise and PA for health promotion and disease prevention and treatment in older adults. Exercise prescription is discussed in terms of the specific modalities and doses that have been studied in randomised controlled trials for their effectiveness in attenuating physiological changes of ageing, disease prevention, and/or improvement of older adults with chronic disease and disability. Recommendations are proposed to bridge gaps in the current literature and to optimise the use of exercise/PA both as a preventative medicine and as a therapeutic agent.

Cardiorespiratory Adaptations in Elderly Men Following Different Concurrent Training Regimes.

BACKGROUND: This study aimed to investigate the effects of different intra-session exercise orders during concurrent training (CT) on endurance performance in elderly men, as well as to verify its influence on individual responses in endurance performance. DESIGN: Twenty-five healthy elderly men (64.7 ± 4.1 years) were placed into two groups: strength training prior to endurance training (SE, n=13), and one in the reverse order (ES, n=12). CT was performed three times a week during 12 weeks. Before and after training, peak oxygen uptake (VO2peak), maximal workload (Wmax), absolute and relative cycling economy at 25, 50, 75 and 100 W (i.e., average VO2 at different stages) were assessed. RESULTS: Similar increases in VO2peak were observed in the SE and ES groups (SE: 8.1 ± 9.9%; ES: 9.3 ± 9.8%; P<0.001), as well as in Wmax (SE: 19.9 ± 19.3%; ES: 24.1 ± 24.0%; P<0.001). Moreover, significant reductions were observed in the absolute VO2 at 100 W (P<0.05) in the SE and ES groups. No difference between groups was observed. In the ES group, one subject did not respond positively in terms of both VO2max and Wmax, whereas 4 subjects did not respond positively in terms of both VO2max and Wmax in SE group. CONCLUSIONS: CT improved maximal and submaximal endurance performance in elderly men, independent of intra-session exercise order. However, it seems that the ES order elicited more individual responsiveness in terms of maximal endurance performance than SE order.

The effects of flexibility training on exercise-induced muscle damage in young men with limited hamstrings flexibility.

Adaptations to 6 weeks of supervised hamstring stretching training and its potential impact on symptoms of eccentric exercise-induced muscle damage (EIMD) were studied in 10 young, untrained men with limited hamstrings flexibility. Participants performed unilateral flexibility training (experimental leg; EL) on an isokinetic dynamometer, while the contralateral limb acted as control (CL). Hip range of motion (ROM), passive, isometric, and concentric torques, active optimum angle, and biceps femoris and semitendinosus muscle thickness and ultrasound echo intensity were assessed both before and after the training. Additionally, muscle soreness was assessed before and after an acute eccentric exercise bout in both legs (EL and CL) at post-training only. Hip ROM increased (P < .001) only in EL after the training (EL = 10.6° vs CL = 1.6°), but no changes (P > .05) in other criterion measurements were observed. After a bout of eccentric exercise at the end of the program, isometric and dynamic peak torques and muscle soreness ratings were significantly altered at all time points equally in EL and CL. Also, active optimum angle was reduced immediately, 48 and 72 hours post-exercise, and hip ROM was reduced at 48 and 72 hours equally in EL and CL. Finally, biceps femoris muscle thickness was significantly increased at all time points, and semitendinosus thickness and echo intensity significantly increased at 72 hours, with no significant differences between legs. The stretching training protocol significantly increased hip ROM; however, it did not induce a protective effect on EIMD in men with tight hamstrings.

Physical Activity and Early Rehabilitation in Hospitalized Elderly Medical Patients: Systematic Review of Randomized Clinical Trials.

BACKGROUND: To critically review the effect of interventions incorporating exercise and early rehabilitation (physical therapy, occupational therapy, and physical activity) in the functional outcomes (i.e., active daily living tests, such as Barthel Index Scores, Timed-up-and go, mobility tests), and feasibility in hospitalized elderly medical patients. DESIGN: Systematic review of the literature. METHODS: A literature search was conducted using the following databases and medical resources from 1966 to January 2014: PubMed (Medline), PEDro, the Cochrane Central Register of Controlled Trials and the Cochrane Database of Systematic Reviews, Google Scholar, ClinicalTrials.gov, Clinical Evidence, SportsDiscus, EMBASE and UptoDate. Studies must have mentioned the effects of early rehabilitation on the above mentioned functional outcomes and feasibility. Data on the mortality, economic profile and average stay were also described. RESULTS: From the 6564 manuscripts potentially related to exercise performance in hospitalized elderly patients, the review focused on 1086, and 17 articles were ultimately included. Regarding functional outcomes after discharge, four studies observed significant improvement in functional outcomes following early rehabilitation, even up to twelve months after discharge. Eight studies directly or indirectly assessed the economic impact of exercise intervention. Five of them did not show any increase in costs, while three concluded that the intervention was cost effective. No adverse effect related with the interventions were mentioned. CONCLUSION: The introduction of an exercise program for hospitalized elderly patients may be feasible, and may not increase costs. Importantly, early rehabilitation may also improve the functional and healthcare.

One session of partial-body cryotherapy (-110 °C) improves muscle damage recovery.

To evaluate the effects of a single session of partial-body cryotherapy (PBC) on muscle recovery, 26 young men performed a muscle-damaging protocol that consisted of five sets of 20 drop jumps with 2-min rest intervals between sets. After the exercise, the PBC group (n = 13) was exposed to 3 min of PBC at -110 °C, and the control group (n = 13) was exposed to 3 min at 21 °C. Anterior thigh muscle thickness, isometric peak torque, and muscle soreness of knee extensors were measured pre, post, 24, 48, 72, and 96 h following exercise. Peak torque did not return to baseline in control group (P < 0.05), whereas the PBC group recovered peak torques 96 h post exercise (P > 0.05). Peak torque was also higher after PBC at 72 and 96 h compared with control group (P < 0.05). Muscle thickness increased after 24 h in the control group (P < 0.05) and was significantly higher compared with the PBC group at 24 and 96 h (P < 0.05). Muscle soreness returned to baseline for the PBC group at 72 h compared with 96 h for controls. These results indicate that PBC after strenuous exercise may enhance recovery from muscle damage.

Oxygen uptake, muscle activity and ground reaction force during water aerobic exercises.

This study aimed to compare the oxygen uptake (VO2), the muscle activity of lower limbs, and the vertical ground reaction force (V-GRF) of women performing water aerobic exercises at different intensities. 12 young women performed the experimental protocol, which consisted of 3 water exercises (stationary running [SR], frontal kick [FK] and cross country skiing [CCS]) at 3 intensities (first and second ventilatory thresholds and maximum effort). A two-way repeated measures ANOVA was used. Regarding VO2, different responses between intensities (p<0.001) were found, and values between exercises were similar. For electromyographic activity (EMG), differences between intensities for all muscles (p<0.001) were found. Greater EMG signals were observed in the FK compared to SR for rectus femoris, semitendinosus, vastus lateralis and biceps femoris muscles (p<0.05). Regarding V-GRF, there was an increase in the V-GRF at greater intensities compared to the first ventilatory threshold (p=0.001). In addition, lower values were found during CCS compared to the SR and FK exercises (p<0.001). Thus, greater cardiorespiratory and neuromuscular responses were observed with increasing intensity. Exercises such as CCS could be used to attenuate the V-GRF; if the purpose is to reduce the muscular activity of lower limbs at a specific intensity, SR could be recommended.

Effects of partial-body cryotherapy (- 110°C) on muscle recovery between high-intensity exercise bouts.

The aim of this study was to evaluate the effects of a single partial-body cryotherapy bout between training sessions on strength recovery. 12 young men (23.9±5.9 years) were randomly exposed to 2 different conditions separated by 7 days: 1) Partial-body cryotherapy (subjects were exposed to 3 min of partial-body cryotherapy at - 110 °C between 2 high-intensity training sessions); 2) Control (subjects were not exposed to partial-body cryotherapy between 2 high-intensity training sessions). Subjects were exposed to partial-body cryotherapy after the first training session. The 2 knee extension high-intensity training sessions were separated by a 40-min rest interval. Knee extension training consisted of 6 sets of 10 repetitions at 60°.s(-1) for concentric actions and 6 sets of 10 at 180.s(-1) for eccentric actions. The decrease in eccentric peak torque and total work was significantly (p<0.05) less after partial-body cryotherapy (5.6 and 2%, respectively) when compared to control (16 and 11.6%, respectively). However, the decrease in concentric peak torque and total work was not different (p>0.05) between partial-body cryotherapy (9.4 and 6.5%, respectively) and control (7.5 and 5.2%, respectively). These results indicate that the use of partial-body cryotherapy between-training sessions can enhance eccentric muscle performance recovery.

Muscle conduction velocity, strength, neural activity, and morphological changes after eccentric and concentric training.

This study compared the effects of concentric and eccentric training on neuromuscular adaptations in young subjects. Twenty-two men and women were assigned to one of two groups: concentric (CON, n = 11) and eccentric (ECC, n = 11) training. Training consisted of 6 weeks of isokinetic exercise, performed twice weekly, starting with two sets of eight repetitions, and progressing to five sets of 10 repetitions. Subjects were tested in strength variables [concentric, eccentric, and isometric peak torque (PT), and rate of force development (RFD)], muscle conduction velocity (CV), neuromuscular activity, vastus lateralis (VL) muscle thickness, and echo intensity as determined by ultrasonography. There were similar increases in the concentric and eccentric PTs in both the CON and ECC groups (P < 0.01), but only the ECC group showed an increase in isometric PT (P < 0.001). Similarly, both groups exhibited increased VL muscle thickness, CV, and RFD, and reduced VL echo intensity (P < 0.05). Significant correlations were observed among the relative changes in the neuromuscular outcomes and training variables (e.g., total work, average PT) (r = 0.68-0.75, P < 0.05). The results showed that both training types similarly improved dynamic PT, CV, RFD, and muscle thickness and quality during the early weeks of training.

Effects of intra-session exercise sequence during water-based concurrent training.

The aim was to investigate the effects of the intra-session exercise order during water-based concurrent training on the neuromuscular adaptations in young women. 26 women (25.1±2.9 years) were placed into 2 groups: resistance prior to (RA) or after (AR) aerobic training. Subjects performed resistance (sets at maximal effort) and aerobic training (exercises at heart rate corresponding to the second ventilatory threshold) twice a week over 12 weeks, performing both exercise types in the same training session. Upper (elbow flexion) and lower-body (knee extension) one-repetition maximum test (1RM) and peak torque (PT) were evaluated. The muscle thickness (MT) of upper (sum of MT of biceps brachii and brachialis) and lower-body (sum of MT of vastus lateralis, vastus medialis, vastus intermedius, and rectus femoris) was determined by ultrasonography. Moreover, the maximal electromyographic activity (EMG) of upper (biceps brachii) and lower-body (sum of EMG of vastus lateralis and rectus femoris) was measured. Both RA and AR groups increased the upper and lower-body 1RM and PT, while the lower-body 1RM increases observed in the RA was greater than AR (43.58±14.00 vs. 27.01±18.05%). RA and AR showed MT increases in all muscles evaluated, while the lower-body MT increases observed in the RA were also greater than AR (10.24±3.11 vs. 5.76±1.88%). There were increases in the maximal EMG of upper and lower-body in both RA and AR, with no differences between groups. Performing resistance prior to aerobic exercise during water-based concurrent training seems to optimize the lower-body strength and hypertrophy.

Determining the anaerobic threshold in water aerobic exercises: a comparison between the heart rate deflection point and the ventilatory method.

AIM: The aim of this study was to compare the cardiorespiratory variables corresponding to the anaerobic threshold (AT) between different water-based exercises using two methods of determining the AT, the heart rate deflection point and ventilatory method, and to correlate the variables in both methods. METHODS: Twenty young women performed three exercise sessions in the water. Maximal tests were performed in the water-based exercises stationary running, frontal kick and cross country skiing. The protocol started at a rate of 80 cycles per minute (cycle.min-1) for 2 min with subsequent increments of 10 cycle.min-1 every minute until exhaustion, with measurements of heart rate, oxygen uptake and ventilation throughout test. After, the two methods were used to determine the values of these variables corresponding to the AT for each of the exercises. Comparisons were made using two-way ANOVA for repeated measures with Bonferroni's post hoc test. To correlate the same variables determined by the two methods, the intra-class correlation coefficient test (ICC) was used. RESULTS: For all the variables, no significant differences were found between the methods of determining the AT and the three exercises. Moreover, the ICC values of each variable determined by the two methods were high and significant. CONCLUSION: The estimation of the heart rate deflection point can be used as a simple and practical method of determining the AT, which can be used when prescribing these exercises. In addition, these cardiorespiratory parameters may be determined performing the test with only one of the evaluated exercises, since there were no differences in the evaluated variables.

Correlations between serum hormones, strength and endurance in healthy elderly South-American men.

AIM: Declines in muscular strength resulting from reduced serum anabolic hormones and neural activity may influence the reduction in aerobic capacity in older men. However, there has been little investigation into the relationship between steroid hormones and muscular strength, as well as endurance capacity in elderly subjects. The purpose of this study was to investigate the possible relationship between serum steroid hormones, strength and aerobic performance in older men. METHODS: Twenty-eight aged men (65±4 years) were evaluated in dynamic strength (one repetition maximum test), isometric strength (maximal voluntary contraction) and rate of force development. Peak oxygen uptake and maximal workload were determined during a ramp protocol on a cycle ergometer. In addition, blood samples were taken to determine basal cortisol, total and free testosterone. RESULTS: No correlations were found between steroid hormonal concentrations and the performance parameters investigated. CONCLUSION: Our results suggest that single measurements of steroids hormones concentrations are not related to the strength and endurance capacity of healthy South-American elderly men.

Vertical ground reaction force during water exercises performed at different intensities.

The aim of the present study was to compare the peak vertical ground reaction force (V-GRF(peak)) and impulse of women performing water aerobic exercises at different intensities in aquatic and dry land environments. 15 young women performed 1 session in each environment consisting of 3 water aerobic exercises (stationary running, frontal kick and cross country skiing) performed at 3 cadences (first ventilatory threshold, second ventilatory threshold and maximum effort, as determined during exercise in water) in a randomized order. 2-way and 3-way repeated measures ANOVA were used to analyze the impulse and V-GRF(peak), respectively. Significantly lower values of V-GRF(peak) and impulse (p<0.001) were observed for the aquatic environment. Significant differences were observed among all cadences for V-GRF(peak) and impulse (p<0.001) in both environments except for the V-GRF(peak) between the cadences corresponding to the second ventilatory threshold and maximum effort in the aquatic environment. In addition, significantly lower V-GRF(peak) values in the aquatic environment were found for cross country skiing compared to the other exercises (p<0.001). Thus, water exercises are safe for people that need to minimize vertical ground reaction force; however, an important issue to be considered during water aerobics training is the exercise and intensity to be prescribed.

How to simultaneously optimize muscle strength, power, functional capacity, and cardiovascular gains in the elderly: an update.

The purpose of the present study was to review the scientific literature that investigated concurrent training adaptations in elderly populations, with the aim of identifying the optimal combination of both training program variables (i.e., strength and endurance) to avoid or minimize the interference effect in the elderly. Scielo, Science Citation Index, MEDLINE, Scopus, SPORTDiscus, and ScienceDirect databases were searched. Concurrent training is the most effective strategy by which to improve neuromuscular and cardiorespiratory functions as well as functional capacity in the elderly. The volume and frequency of training appears to play a critical role in concurrent training-induced adaptations in elderly subjects. Furthermore, new evidence indicates that the intra-session exercise order may influence the magnitude of physiological adaptations. Despite the interference effect on strength gains that is caused by concurrent training, this type of training is advantageous in that the combination of strength and endurance training produces both neuromuscular and cardiovascular adaptations in the elderly. The interference phenomenon may be observed in elderly subjects when a moderate weekly volume of concurrent training (i.e., three times per week) is performed. However, even with the occurrence of this phenomenon, the performance of three concurrent training sessions per week appears to optimize the strength gains in relative brief periods of training (12 weeks). Moreover, performing strength prior to endurance exercise may optimize both neuromuscular and cardiovascular gains.

3 Different types of strength training in older women.

The objective of the present study was to evaluate and compare the neuromuscular, morphological and functional adaptations of older women subjected to 3 different types of strength training. 58, healthy women (67 ± 5 year) were randomized to experimental (EG, n=41) and control groups (CG, n=17) during the first 6 weeks when the EG group performed traditional resistance exercise for the lower extremity. Afterwards, EG was divided into three specific strength training groups; a traditional group (TG, n=14), a power group (PG, n=13) that performed the concentric phase of contraction at high speed and a rapid strength group (RG, n=14) that performed a lateral box jump exercise emphasizing the stretch-shortening-cycle (SSC). Subjects trained 2 days per week through the entire 12 weeks. Following 6 weeks of generalized strength training, significant improvements occurred in EG for knee extension one-repetition (1RM) maximum strength (+19%), knee extensor muscle thickness (MT, +15%), maximal muscle activation (+44% average) and onset latency ( -31% average) for vastus lateralis (VL), vastus medialis (VM) and rectus femoris (RF) compared to CG (p<0.05). Following 6 more weeks of specific strength training, the 1RM increased significantly and similarly between groups (average of +21%), as did muscle thickness of the VL (+25%), and activation of VL (+44%) and VM (+26%). The onset latency of RF (TG=285 ± 109 ms, PG=252 ± 76 ms, RG=203 ± 43 ms), reaction time (TG=366 ± 99 ms, PG=274 ± 76 ms, RG=201 ± 41 ms), 30-s chair stand (TG=18 ± 3, PG=18 ± 1, RG=21 ± 2) and counter movement jump (TG=8 ± 2 cm, PG=10 ± 3 cm, RG=13 ± 2 cm) was significantly improved only in RG (p<0.05). At the end of training, the rate of force development (RFD) over 150 ms (TG=2.3 ± 9.8 N·s(-1), PG=3.3 ± 3.2 N·s(-1), RG=3.8 ± 6.8 N·s(-1), CG=2.3 ± 7.0 N·s(-1)) was significantly greater in RG and PG than in TG and CG (p<0.05). In conclusion, rapid strength training is more effective for the development of rapid force production of muscle than other specific types of strength training and by consequence, better develops the functional capabilities of older women.

Concurrent training with different aerobic exercises.

The aim of the present study was to compare the effects of using different intensities and types of aerobic exercise (i. e., cycle ergometer or running) during concurrent training on neuromuscular adaptations. A total of 44 young women were randomly assigned to 1 of 4 groups: concurrent strength and continuous running training (SCR, n=10), concurrent strength and interval running training (SIR, n=11), concurrent strength and continuous cycle ergometer training (SCE, n=11), or strength training only (STO, n=12). Each group trained twice a week during 11 weeks. The following strength measurements were made on all subjects before and after training period: maximal strength (1RM) in knee extension, bench press and leg press exercises; local muscular endurance (number of repetitions at 70% of 1 RM) in knee extension and bench press exercises; and isometric and isokinetic peak torque of knee extension. There were significant increases in the upper and lower-body 1 RM, isometric and isokinetic peak torque in all training groups (p<0.001), with no differences between groups. The present results suggest that in young women, concurrent training performed twice a week promotes similar neuromuscular adaptations to strength training alone, regardless of the type and the intensity in which the aerobic training is performed.

Cardiorespiratory and neuromuscular responses during water aerobics exercise performed with and without equipment.

The aim of the study was to compare the cardiorespiratory and neuromuscular responses to water aerobics exercise performed with and without equipment. 15 women performed stationary jogging combined with elbow flexion/extension without equipment, with water-drag forces equipment and with water-floating equipment, at 2 submaximal cadences and at maximal cadence. Heart rate, oxygen uptake and electromyographic signal from biceps brachii, triceps brachii, biceps femoris and rectus femoris were collected during the exercise. The heart rate and oxygen uptake showed significantly higher values during the execution of the water aerobics exercise with either equipment compared to the execution without equipment. In addition, significant difference was found between submaximal cadences. For neuromuscular responses, no significant differences were found between the submaximal cadences for all muscles analyzed; however, significant differences were found between these submaximal cadences and the maximal cadence. Similarly, the results showed no significant differences between the execution of the exercise with or without equipment, except in the muscle activation of triceps brachii and biceps femoris, which was higher when using water-floating and water-drag forces equipment, respectively. In conclusion, the water aerobics exercise presented higher cardiorespiratory responses with equipment and also increased the cadence of execution. Nevertheless, neuromuscular responses were higher only at maximal cadence.

Molecular aspects involved in swimming exercise training reducing anhedonia in a rat model of depression.

Patients suffering from depression frequently display hyperactivity of the hypothalamic-pituitary-adrenal axis (HPA) resulting in elevated cortisol levels. One main symptom of this condition is anhedonia. There is evidence that exercise training can be used as a rehabilitative intervention in the treatment of depressive disorders. In this scenario, the aim of the present study was to assess the effect of an aerobic exercise training protocol on the depressive-like behavior, anhedonia, induced by repeated dexamethasone administration. The study was carried out on adult male Wistar rats randomly divided into four groups: the "control group" (C), "exercise group" (E), "dexamethasone group" (D) and the "dexamethasone plus exercise group" (DE). The exercise training consisted of swimming (1 h/d, 5 d/wk) for 3 weeks, with an overload of 5% of the rat body weight. Every day rats were injected with either dexamethasone (D/DE) or saline solution (C/E). Proper positive controls, using fluoxetine, were run in parallel. Decreased blood corticosterone levels, reduced adrenal cholesterol synthesis and adrenal weight (HPA disruption), reduced preference for sucrose consumption and increased immobility time (depressive-like behavior), marked hippocampal DNA oxidation, increased IL-10 and total brain-derived neurotrophic factor (BDNF; pro-plus mature-forms) and a severe loss of body mass characterized the dexamethasone-treated animals. Besides increasing testosterone blood concentrations, the swim training protected depressive rats from the anhedonic state, following the same profile as fluoxetine, and also from the dexamethasone-induced impaired neurochemistry. The data indicate that physical exercise could be a useful tool in preventing and treating depressive disorders.