990 research outputs found
Implementing Low-Cost, Community-Based Exercise Programs for Middle-Aged and Older Patients with Type 2 Diabetes: What Are the Benefits for Glycemic Control and Cardiovascular Risk?
Background: The purpose of this study was to analyze the effects of a long-term, community-based, combined exercise program developed with low-cost exercise strategies on glycemic control and cardiovascular risk factors in middle-aged and older patients with type 2 diabetes. Methods: Participants (n = 124; 63.25 ± 7.20 years old) engaged in either a 9-month supervised exercise program (n = 39; consisting of combined aerobic, resistance, agility/balance, and flexibility exercise; three sessions per week; 70 min per session) or a control group (n = 85) who maintained their usual care. Glycemic control, lipid profile, blood pressure, anthropometric profile, and the 10-year risk of coronary artery disease were assessed before and after the 9-month intervention. Results: A significant time * group interaction effect (p < 0.001) was identified in the values of the glycated hemoglobin, fasting plasma glucose, total cholesterol, LDL cholesterol, HDL cholesterol, triglycerides, systolic blood pressure, diastolic blood pressure, body mass index, waist circumference, and the 10-year risk of coronary artery disease. Conclusions: A long-term, community-based, combined exercise program developed with low-cost exercise strategies was effective in inducing significant benefits on glycemic control, lipid profile, blood pressure, anthropometric profile, and the 10-year risk of coronary artery disease in middle-aged and older patients with type 2 diabetes. Clinical Trial Identification Number: ISRCTN09240628.We gratefully acknowledge the participants of the study and Cova da Beira Hospital Centre for the possibility to perform this research. This study was supported by a grant from the Portuguese Foundation for Science and Technology (SFRH/BD/47733/2008)
High-Intensity Interval Training Versus Moderate-Intensity Continuous Training in Middle-Aged and Older Patients with Type 2 Diabetes: A Randomized Controlled Crossover Trial of the Acute Effects of Treadmill Walking on Glycemic Control
Background: This study aimed to compare the acute effects of high-intensity interval training (HIIT) versus moderate-intensity continuous training (MICT) on glycemic control in middle-aged and older patients with type 2 diabetes (T2D), using treadmill walking as aerobic exercise mode. Methods: Fifteen patients with T2D (60.25 ± 3.14 years; glycated hemoglobin 7.03 ± 0.33%; medicated with metformin and/or gliptins), participated in a randomized controlled crossover trial. They underwent three experimental conditions (treadmill walking HIIT session (5 × (3 min at 70% of heart rate reserve (HRR) + 3 min at 30% HRR)); treadmill walking MICT session (30 min at 50% HRR); and a control session of rest (CON)) in random order and in the postprandial state. Measurements of capillary blood glucose (BG) were taken immediately before, during, and until 50 min after the experimental conditions. Results: Both HIIT and MICT treadmill walking sessions reduced BG levels during exercise and laboratory 50 min recovery period compared to CON (time*condition interaction effect; p < 0.001). The effect of HIIT was greater compared with MICT (p = 0.017). Conclusions: Treadmill walking HIIT seems a safe and more effective exercise strategy on immediate acute glycemic control compared with MICT in middle-aged and older patients with T2D under therapy with metformin and/or gliptins. Trial Registration Number: ISRCTN09240628.This research was funded by the Portuguese Foundation for Science and Technology (grant number SFRH/BD/47733/2008), and the APC was funded by the authors
Physiological assessment of head-out aquatic exercises in healthy subjects: a qualitative review
In the last decades head-out aquatic exercises became one of the most important physical activities within the health system. Massive research has been produced throughout these decades in order to better understand the role of head-out aquatic exercises in populations' health. Such studies aimed to obtain comprehensive knowledge about the acute and chronic response of subjects performing head-out aquatic exercises. For that, it is assumed that chronic adaptations represent the accumulation of acute responses during each aquatic session. The purpose of this study was to describe the "state of the art "about physiological assessment of head-out aquatic exercises based on acute and chronic adaptations in healthy subjects based on a qualitative review. The main findings about acute response of head-out aquatic exercise according to water temperature, water depth, type of exercise, additional equipment used, body segments exercising and music cadence will be described. In what concerns chronic adaptations, the main results related to cardiovascular and metabolic adaptations, muscular strength, flexibility and body composition improvements will be reported. Key pointsSeveral papers reported consistent and significant improvement in physical fitness (e.g., aerobic capacity, muscular strength, flexibility and body composition) after a program of head-out aquatic exercise with at least eight weeks.Chronic adaptations to head-out aquatic exercise programs are the cumulative result of appropriate acute responses during the exercise session.Appropriate acute adaptations can be obtained taking into account the water temperature, water depth, type of exercise and its variants, the equipment used and the segmental cadence according to the subjects' profile.info:eu-repo/semantics/publishedVersio
Can the curriculum be used to estimate critical velocity in young competitive swimmers?
The aims of the present study were to assess critical velocity using the swimmer curriculum in front crawl events and to compare critical velocity to the velocity corresponding to a 4 mmol·l(-1) of blood lactate concentration and to the velocity of a 30 min test. The sample included 24 high level male swimmers ranged between 14 and 16 years old. For each subject the critical velocity, the velocity corresponding to a 4 mmol·l(-1) of blood lactate concentration and the mean velocity of a 30 min test were determined. The critical velocity was also estimated by considering the best performance of a swimmer over several distances based on the swimmer curriculum. Critical velocity including 100, 200 and 400 m events was not different from the velocity of 4 mmol·l(-1) of blood lactate concentration. Critical velocity including all the swimmer events was not different from the velocity of a 30 min test. The assessment of critical velocity based upon the swimmer curriculum would therefore seem to be a good approach to determine the aerobic ability of a swimmer. The selection of the events to be included in critical velocity assessment must be a main concern in the evaluation of the swimmer. Key pointsCritical velocity using 100, 200 and 400 m events was not different from the velocity of 4 mmol·l(-1) of blood lactate concentration.Critical velocity using all the swimmer events was not different from the velocity of a 30 min test.The assessment of critical velocity based upon the swimmer curriculum seemed to be a good approach to determine the aerobic capacity of a swimmer.The decision on the events to be analysed must be a main concern in the evaluation of the swimmer critical velocity.info:eu-repo/semantics/publishedVersio
Evaluation of nitrogen fertilizer and inoculation with diazotrophic bacteria on the biochemical behavior of the maize cultivar nitroflint
The evaluation of nitrogen fertilizer and inoculation with diazotrophic bacteria on the genetic and biochemical behavior of the maize (Zea mays L.) cultivar Nitroflint were performed in two experiments, one in the field and the other in greenhouse. The experimental set up consisted of a randomized blocks design with three replications and two evaluation factors, inoculation (or not) with diazotrophic bacteria and nitrogen fertilizer levels (100 kg/ha of N and 10 kg/ha of N). In the field experiment the following parameters were measured: grain production, total plant nitrogen (above ground), grain nitrogen and activities of the enzymes nitrate reductase and glutamine synthetase. In the second experiment (greenhouse), fresh weight of the plant, glutamine synthetase (transferase and synthetase) and nitrate reductase activities were determined for both leaf and root tissue. A bacterial count was made in three media, denominated LGI (semi-selective for Azospirillum amazonense), JNFb (Herbaspirillum spp.) and NFb (Azospirillum spp.) for the shoot and the root. Results of the field experiment showed an effect of N fertilizer on total N and grain production. The second experiment (greenhouse) showed an effect of N fertilizer on all parameters measured and inoculation was effective on glutamine synthetase activity of the root by transferase reaction. A correlation was obtained between root glutamine synthetase activity and bacterial growth in LGI.33696197
Macrophage Targeting pH Responsive Polymersomes for Glucocorticoid Therapy
Glucocorticoid (GC) drugs are the cornerstone therapy used in the treatment of inflammatory diseases. Here, we report pH responsive poly(2-methacryloyloxyethyl phosphorylcholine)–poly(2-(diisopropylamino)ethyl methacrylate) (PMPC–PDPA) polymersomes as a suitable nanoscopic carrier to precisely and controllably deliver GCs within inflamed target cells. The in vitro cellular studies revealed that polymersomes ensure the stability, selectivity and bioavailability of the loaded drug within macrophages. At molecular level, we tested key inflammation-related markers, such as the nuclear factor-κB, tumour necrosis factor-α, interleukin-1β, and interleukin-6. With this, we demonstrated that pH responsive polymersomes are able to enhance the anti-inflammatory effect of loaded GC drug. Overall, we prove the potential of PMPC–PDPA polymersomes to efficiently promote the inflammation shutdown, while reducing the well-known therapeutic limitations in GC-based therapy
Does combined dry land strength and aerobic training inhibit performance of young competitive swimmers?
The aim of the current study was twofold: (i) to examine the
effects of eight weeks of combined dry land strength and aerobic
swimming training for increasing upper and lower body
strength, power and swimming performance in young competitive
swimmers and, (ii) to assess the effects of a detraining
period (strength training cessation) on strength and swimming
performance. The participants were divided into two groups: an
experimental group (eight boys and four girls) and a control
group (six boys and five girls). Apart from normal practice
sessions (six training units per week of 1 h and 30 min per day),
the experimental group underwent eight weeks (two sessions per
week) of strength training. The principal strength exercises were
the bench press, the leg extension, and two power exercises such
as countermovement jump and medicine ball throwing. Immediately
following this strength training program, all the swimmers
undertook a 6 week detraining period, maintaining the normal
swimming program, without any strength training. Swimming
(25 m and 50 m performances, and hydrodynamic drag values),
and strength (bench press and leg extension) and power (throwing
medicine ball and countermovement jump) performances
were tested in three moments: (i) before the experimental period,
(ii) after eight weeks of combined strength and swimming
training, and (iii) after the six weeks of detraining period. Both
experimental and control groups were evaluated. A combined
strength and aerobic swimming training allow dry land strength
developments in young swimmers. The main data can not
clearly state that strength training allowed an enhancement in
swimming performance, although a tendency to improve sprint
performance due to strength training was noticed. The detraining
period showed that, although strength parameters remained
stable, swimming performance still improved.info:eu-repo/semantics/publishedVersio
Analysis of drafting effects in swimming using computational fluid dynamics
The purpose of this study was to determine the effect of drafting distance on the drag coefficient in swimming. A k-epsilon turbulent model was implemented in the commercial code Fluent(®) and applied to the fluid flow around two swimmers in a drafting situation. Numerical simulations were conducted for various distances between swimmers (0.5-8.0 m) and swimming velocities (1.6-2.0 m.s(-1)). Drag coefficient (Cd) was computed for each one of the distances and velocities. We found that the drag coefficient of the leading swimmer decreased as the flow velocity increased. The relative drag coefficient of the back swimmer was lower (about 56% of the leading swimmer) for the smallest inter-swimmer distance (0.5 m). This value increased progressively until the distance between swimmers reached 6.0 m, where the relative drag coefficient of the back swimmer was about 84% of the leading swimmer. The results indicated that the Cd of the back swimmer was equal to that of the leading swimmer at distances ranging from 6.45 to 8. 90 m. We conclude that these distances allow the swimmers to be in the same hydrodynamic conditions during training and competitions. Key pointsThe drag coefficient of the leading swimmer decreased as the flow velocity increased.The relative drag coefficient of the back swimmer was least (about 56% of the leading swimmer) for the smallest inter-swimmer distance (0.5 m).The drag coefficient values of both swimmers in drafting were equal to distances ranging between 6.45 m and 8.90 m, considering the different flow velocities.The numerical simulation techniques could be a good approach to enable the analysis of the fluid forces around objects in water, as it happens in swimming.info:eu-repo/semantics/publishedVersio
The use of neural network technology to model swimming performance
to identify the factors which are able to explain the performance in the 200 meters individual medley and 400 meters front crawl events in young swimmers, to model the performance in those events using non-linear mathematic methods through artificial neural networks (multi-layer perceptrons) and to assess the neural network models precision to predict the performance. A sample of 138 young swimmers (65 males and 73 females) of national level was submitted to a test battery comprising four different domains: kinanthropometric evaluation, dry land functional evaluation (strength and flexibility), swimming functional evaluation (hydrodynamics, hydrostatic and bioenergetics characteristics) and swimming technique evaluation. To establish a profile of the young swimmer non-linear combinations between preponderant variables for each gender and swim performance in the 200 meters medley and 400 meters font crawl events were developed. For this purpose a feed forward neural network was used (Multilayer Perceptron) with three neurons in a single hidden layer. The prognosis precision of the model (error lower than 0.8% between true and estimated performances) is supported by recent evidence. Therefore, we consider that the neural network tool can be a good approach in the resolution of complex problems such as performance modeling and the talent identification in swimming and, possibly, in a wide variety of sports. Key pointsThe non-linear analysis resulting from the use of feed forward neural network allowed us the development of four performance models.The mean difference between the true and estimated results performed by each one of the four neural network models constructed was low.The neural network tool can be a good approach in the resolution of the performance modeling as an alternative to the standard statistical models that presume well-defined distributions and independence among all inputs.The use of neural networks for sports sciences application allowed us to create very realistic models for swimming performance prediction based on previous selected criterions that were related with the dependent variable (performance).info:eu-repo/semantics/publishedVersio
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