Impact of diet,exercise end diet combined with exercise programs on plasma lipoprotein and adiponectin levels in obese girls

We studied the effect of three programs, diet restriction (D), individualized exercise training (E) at the maximal lipid oxidation point (LIPOXmax) and diet combined with exercise (D+E), on body mass, plasma lipoprotein and adiponectin levels in obese girls. Eighteen obese adolescents girls aged 12-14 years were studied. A longitudinal intervention was carried out, consisting of a two-month diet (D; -500 kcal·day-1), of individualized exercise (E; 4 days/week, 90 min·day-1) and of diet combined with exercise (D+E). Body mass, body mass index (BMI), body fat mass, waist circumference, substrate crossover point, LIPOXmax point, homeostasis model assessment (HOMA-IR) index, fasting levels of lipids and circulatory adiponectin, were measured in all subjects before and after the program. In subjects of the D+E group, body mass, BMI, body fat mass, waist circumference, HOMA-IR, low-density lipoprotein cholesterol (LDL-C) and total cholesterol / high-density lipoprotein cholesterol (TC/HDL-C) ratio were significantly lower, and HDL-C and adiponectin were higher after the program than that of subjects in the D or E groups. Diet/exercise improved the ability to oxidize lipids during exercise (crossover point: + 18.5 ± 3.4 of % Wmax; p < 0.01 and fat oxidation rate at LIPOXmax: + 89.7 ± 19.7 mg·min^-1; p < 0.01). In the D+E group, significant correlations were found between changes in body mass and adiponectin and between changes in the TC/HDL-C ratio and LIPOXmax. These findings show that the combined program of diet restriction and individualized exercise training at the LIPOXmax point is necessary to simultaneously improve body mass loss, adiponectin levels, as well as metabolic parameters, in obese girls.

Key points

• Diet combined with exercise training improved body composition, adiponectin levels and metabolic parameters in obese girls.
• Diet only decreases body mass and LDL-C without improving fat oxidation and HDL- C.
• Individualized exercise training at LIPOXmax point improved the HDL-C and the circulatory adiponectin levels with any change of LDL-C and body composition.

Key words: Obese girls, lipoprotein, adiponectin, exercise training, diet restriction     

Resistance Band Exercise Training Prevents the Progression of Metabolic Syndrome in Obese Postmenopausal Women

Metabolic syndrome (MetS) is classified as a combination of risk factors for cardiovascular disease (CVD), and postmenopausal women are specifically at an increased risk for MetS, in part due to the hormonal and metabolic changes that occur at the menopause transition. It is crucial to combat the components of MetS with appropriate lifestyle interventions in this population, such as exercise. This study aimed to examine the effects of a resistance band exercise training program in obese postmenopausal women with MetS. A total 35 postmenopausal women were randomly assigned to either a control group (CON, n = 17) or a resistance band exercise training group (EX, n = 18). Participants in the EX group trained 3days/week. Levels of blood glucose, insulin, homeostatic model of insulin resistance (HOMA-IR), blood lipid profile, anthropometrics, and blood pressure (BP) were measured at baseline and after the exercise intervention. There were significant group by time interactions (p < 0.05) for blood glucose (Δ-4.5 mg/dl), insulin (Δ -1.3 μU/ml), HOMA-IR (Δ -0.6), triglycerides (Δ -9.4 mg/dl), low-density lipoprotein cholesterol(Δ -10.8 mg/dl), systolic BP(Δ -3.4 mmHg), body fat percentage (Δ -3.0 %), and waist circumference (Δ -3.4 cm), which significantly decreased (p < 0.05), and lean body mass (Δ 0.7 kg) and high-density lipoprotein cholesterol (Δ 5.1 mg/dl), which significantly increased (p < 0.05) after EX compared to no change in CON. The present study indicates that resistance band exercise training may be an effective therapeutic intervention to combat the components of MetS in this population, potentially reducing the risk for the development of CVD.Key points

• There are findings in the study that support the use of resistance band exercise for reducing risks for MetS in this population.
• There were significant improvements in insulin, glucose, HOMA-IR, and blood lipid profiles following the exercise training program.
• Body mass, BMI, BF%, SBP, and waist circumference were significantly decreased, while LBM significantly increased after 12 weeks of exercise training program.
• This is the first study to evaluate the impact of resistance band exercise training on risk factors for MetS in obese postmenopausal women.

Key words: Hyperinsulinemia, HOMA-IR, insulin resistance, resistance training, triglycerides     

Calcineurin-NFAT Signaling and Neurotrophins Control Transformation of Myosin Heavy Chain Isoforms in Rat Soleus Muscle in Response to Aerobic Treadmill Training

This study elucidated the role of CaN-NFAT signaling and neurotrophins on the transformation of myosin heavy chain isoforms in the rat soleus muscle fiber following aerobic exercise training. To do so, we examined the content and distribution of myosin heavy chain (MyHC) isoforms in the rat soleus muscle fiber, the activity of CaN and expression of NFATc1 in these fibers, and changes in the expression of nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF) and neutrophin-3 (NT-3) in the soleus and striatum following high-and medium-intensity aerobic treadmill training. Specific pathogen-free 2 month old male Sprague-Dawley (SD) rats were randomly divided into three groups: Control group (Con, n = 8), moderate-intensity aerobic exercise group (M-Ex, n = 8) and high-intensity aerobic exercise group (H-Ex, n = 8). We used ATPase staining to identify the muscle fiber type I and II, SDS-PAGE to separate and analyze the isoforms MyHCI, MyHCIIA, MyHCIIB and MyHCIIx, and performed western blots to determine the expression of NFATc1, NGF, BDNF and NT-3. CaN activity was measured using a colorimetric assay. In the soleus muscle, 8 weeks of moderate-intensity exercise can induce transformation of MyHC IIA and MyHC IIB to MyHC IIX and MyHC I (p < 0.01), while high-intensity treadmill exercise can induce transform MyHC IIx to MyHC IIB, MyHC IIA and MyHC I (p < 0.01). In comparison to the control group, CaN activity and NFATcl protein level were significantly increased in both the M-Ex and H-Ex groups (p < 0.05, p < 0.01), with a more pronounced upregulation in the M-Ex group (p < 0.05). Eight weeks of moderate- and high-intensity aerobic exercise induced the expression of NGF, BDNF and NT-3 in the soleus muscle and the striatum (p < 0.01), with the most significant increase in the H-Ex group (p < 0.01). In the rat soleus muscle, (1) CaN–NFATcl signaling contributes to the conversion of MyHC I isoform in response to moderate-intensity exercise; (2) Neurotrophins NGF, BDNF and NT-3 might play a role in the conversion of MyHC II isoform in response to high-intensity treadmill exercise.

Key points

• Eight weeks of moderate-intensity treadmill training induces the transformation MyHC IIA and MyHC IIB to MyHC IIX and MyHC I in the soleus muscles, while high-intensity exercise leads to transformation of MyHC IIX to MyHC IIA, MyHC IIB and MyHC I.
• MyHC I conversion in response to moderate-intensity aerobic exercise is mediated by calcineurin-NFATcl signaling.
• Eight weeks of moderate- and high-ntensity aerobic exercise induces the expression of NGF, BDNF and NT-3 in expression noted in rats subjected to high-intensity training. NGF and NT-3 expression in the striatum is lower than in the soleus muscle, while BDNF levels are similar. Neurotrophins may be involved in mediating MyHC II conversion in response to high-intensity aerobic exercise.

Key words: Aerobic treadmill training, the muscle fiber type, neurotrophins, Myosin heavy chain isoforms transformation, Calcineurin/Nuclear factor of activated T cells c1     

The Effects of Regular Aerobic Exercise on Renal Functions in Streptozotocin Induced Diabetic Rats

Diabetic nephropathy is a feared complication of diabetes since it can lead to end-stage renal failure and also it is a risk factor of cardiovascular disease. The important clinical problems caused by diabetic nephropathy are proteinuria and decreased renal function. Exercise is a cornerstone of diabetes management, along with diet and medication. Since acute exercise causes proteinuria and decreases glomerular filtration rate, the effect of exercise on diabetic nephropathy is controversial. The aim of this study was to investigate the effect of regular aerobic exercise on microalbuminuria and glomerular filtration rate in diabetic rats. Moderate diabetes was induced by streptozotocin (45 mg/kg IV) in rats and an aerobic exercise- training program on a treadmill was carried out for 8 weeks. Four groups of rats; control sedentary (CS), control exercise (CE), diabetic sedentary (DS) and diabetic exercise (DE) were included in the study. Blood glucose levels were determined from the plasma samples taken at the end of 4 weeks of stabilization period and 8 weeks of training program. Creatinine clearance (CCr) and microalbuminuria (MA) levels were determined to evaluate renal functions. The analyzed data revealed that regular aerobic exercise: 1) significantly decreased the plasma glucose level of the DE group compared to the DS group (p < 0.05), 2) significantly decreased the microalbuminuria level of the DE group compared to those of DS group (p < 0.01), 3) significantly decreased the creatinine clearance levels of the DE and CE groups compared to those of CS group (p < 0.05). The results of this study suggest that despite of decreasing creatinine clearance, regular submaximal aerobic exercise has a preventive effect on development of microalbuminuria and thus may retard nephropathy in diabetic rats.

Key points

• Regular submaximal aerobic exercise can facilitate the control of blood glucose level in diabetic rats.
• Streptozotocin induced diabetes may cause microalbuminuria and regular submaximal aerobic exercise may have a preventive effect on renal functions.

Key words: Aerobic exercise, microalbuminuria, nephropathy, diabetes mellitus     

Effects of Low-Intensity Cycle Training with Restricted Leg Blood Flow on Thigh Muscle Volume and VO2MAX in Young Men

Concurrent improvements in aerobic capacity and muscle hypertrophy in response to a single mode of training have not been reported. We examined the effects of low-intensity cycle exercise training with and without blood flow restriction (BFR) on muscle size and maximum oxygen uptake (VO₂max). A group of 19 young men (mean age ± SD: 23.0 ± 1.7 years) were allocated randomly into either a BFR-training group (n=9, BFR-training) or a non-BFR control training group (n=10, CON-training), both of which trained 3 days/wk for 8 wk. Training intensity and duration were 40% of VO₂max and 15 min for the BFR-training group and 40% of VO₂max and 45 min for the CON-training group. MRI-measured thigh and quadriceps muscle cross-sectional area and muscle volume increased by 3.4-5.1% (P < 0.01) and isometric knee extension strength tended to increase by 7.7% (p < 0.10) in the BFR-training group. There was no change in muscle size (~0.6%) and strength (~1.4%) in the CON-training group. Significant improvements in VO₂max (6.4%) and exercise time until exhaustion (15.4%) were observed in the BFR-training group (p < 0.05) but not in the CON-training group (-0.1 and 3. 9%, respectively). The results suggest that low-intensity, short-duration cycling exercise combined with BFR improves both muscle hypertrophy and aerobic capacity concurrently in young men.

Key points

• Concurrent improvements in aerobic capacity and muscle hypertrophy in response to a single mode of training have not been reported.
• In the present study, low-intensity (40% of VO2max) cycle training with BFR can elicit concurrent improvement in muscle hypertrophy and aerobic capacity.

Key words: Muscle hypertrophy, Aerobic exercise, Occlusion, Muscle strength     

Serum IGF-I and hormonal responses to incremental exercise in athletes with and without left ventricular hypertrophy

We investigated the response of insulin-like growth factor (IGF- I), insulin-like growth factor binding protein-3 (IGFBP-3) and some hormones, i.e., testosterone (T), growth hormone (GH), cortisol (C), and insulin (I), to maximal exercise in road cyclists with and without diagnosed left ventricular hypertrophy. M-mode and two-dimensional Doppler echocardiography was performed in 30 professional male endurance athletes and a group of 14 healthy untrained subjects using a Hewlett-Packard Image Point HX ultrasound system with standard imaging transducers. Echocardiography and an incremental physical exercise test were performed during the competitive season. Venous blood samples were drawn before and immediately after the maximal cycling exercise test for determination of somatomedin and hormonal concentrations. The basal concentration of IGF-I was statistically higher (p < 0.05) in athletes with left ventricular muscle hypertrophy (LVH) when compared to athletes with a normal upper limit of the left ventricular wall (LVN) (p < 0.05) and to the control group (CG) (p < 0.01). The IGF-I level increased significantly at maximal intensity of incremental exercise in CG (p < 0.01), LVN (p < 0.05) and LVH (p < 0.05) compared to respective values at rest. Long-term endurance training induced an increase in resting (p < 0.01) and post-exercise (p < 0.05) IGF-I/IGFBP-3 ratio in athletes with LVH compared to LVN. The testosterone (T) level was lower in LVH at rest compared to LVN and CG groups (p < 0.05). These results indicate that resting serum IGF-I concentration were higher in trained subjects with LVH compared to athletes without LVH. Serum IGF- I/IGFBP-3 elevation at rest and after exercise might suggest that IGF-I act as a potent stimulant of left ventricular hypertrophy in chronically trained endurance athletes.

Key points

• In sports training athletes engaged in the same training regimen acquired different stages of cardiac hypertrophy.
• Physical exercise had a significant effect on serum insulin-like growth factor - I concentration depending on maximal oxygen uptake during endurance exercise.
• Athletes with clinically diagnosed physiological left ventricular hypertrophy had higher resting serum insulin-like growth factor - I concentration compared to those without left ventricular hypertrophy and sedentary subjects.
• Increased insulin-like growth factor - I release during long-term training seems to significantly contribute to sports-specific functional adaptation of the left ventricle.

Key words: Echocardiography, heart, somatomedins, anabolic hormones, endurance training.     

Influence of Two Different Exercise Programs on Physical Fitness and Cognitive Performance in Active Older Adults: Functional Resistance-Band Exercises vs. Recreational Oriented Exercises

This study examines the impact of a resistance-band functional exercise program, compared with a recreational exercise program, on physical fitness and reaction times in persons older than 60 years. Fifty-four community-dwelling volunteers (71.76 ± 6.02 years) were assigned to a specific exercise program: Functional activity program (focused on resistance-band multi-joint activities; experimental group, EG), or recreational physical activity program (with gross motor activities of ludic content; control group, CG). Before and after the intervention, we determined cognitive capacity in terms of simple reaction time (S-RT), choice reaction time (C-RT) and fitness. In both groups physical performance improved, though this improvement was more marked in the EG for grip strength, arm strength and gross motor abilities (p < 0.05). Reaction times were better only in EG (S-RT = 10.70%, C-RT = 14.34%; p < 0.05) after the corresponding physical training intervention. The training period showed no effect on the moderate relationship between both RT and gross motor abilities in the CG, whereas the EG displayed an enhanced relationship between S-RT and grip-strength as well as the C-RT with arm strength and aerobic capacity (r ~ 0.457; p < 0.05). Our findings indicate that a functional exercise program using a resistance band improves fitness and cognitive performance in healthy older adults.

Key points

• Better cognitive processes can be achieved as physical condition improves
• Exercise sessions of a more recreational type do not seem to constitute a stimulus able to improve both physical and cognitive performance in healthy active older adults
• The improvement of cognitive function, as assessed through reaction times, seems more linked to the workload and strength component of the training program.

Key words: Aging, reaction time, physical activity program, cognitive capacity     

The Effects of Intermittent Exercise on Physiological Outcomes in an Obese Population: Continuous Versus Interval Walking

This study compared the effects of 12 weeks of caloric restriction and interval exercise (INT) and caloric restriction and continuous aerobic exercise (CON) on physiological outcomes in an obese population. Forty-four individuals (BMI ≥ 30 kg·m^-2) were randomised into the INT or CON group. Participant withdrawal resulted in 12 and 14 participants in the INT and CON groups, respectively. All participants were on a strict monitored diet. Exercise involved two 15-min bouts of walking performed on five days per week. Interval exercise consisted of a 2:1 min ratio of low-intensity (40-45% VO_2peak) and high- intensity (70-75% VO_2peak) exercise, while the CON group exercised between 50-55% VO_2peak. Exercise duration and average intensity (%VO_2peak) were similar between groups. There were no significant differences (p > 0.05) between the two groups for any variable assessed apart from very low density lipoprotein (VLDL-C), which significantly decreased over time in the INT group only (p < 0.05, d = 1.03). Caloric restriction and interval exercise compared to caloric restriction and continuous aerobic exercise resulted in similar outcome measures apart from VLDL-C levels, which significantly improved in the INT group only.

Key points

• Twelve weeks of interval exercise and caloric restriction resulted in significant improvement in very low density lipoprotein cholesterol in an obese population, as compared to continuous aerobic exercise and caloric restriction.
• Twelve weeks of either interval exercise or continuous exercise resulted in similar improvements in aerobic fitness in an obese population.

Key words: Interval training, body fat, fitness, metabolism     

Effects of Ballates,Step Aerobics,and Walking on Balance in Women Aged 50–75 Years

This study examined the effectiveness of Ballates training (strengthening of the central core musculature by the inception of balance techniques) compared to more traditional exercise programs, such as step aerobics and walking, on balance in women aged 50- 75 years. Participants were randomly assigned to one of three supervised training groups (1 hour/day, 3 days/week, 13 weeks), Ballates (n = 12), step aerobics (n = 17), or walking (n =15). Balance was measured by four different methods (modified Clinical Test for the Sensory Interaction on Balance - mCTSIB; Unilateral Stance with Eyes Open - US-EO or Eyes Closed - US-EC; Tandem Walk - TW; Step Quick Turn - SQT) using the NeuroCom Balance Master. A 2-way (Group and Trial) repeated measures ANOVA and post-hoc Bonferroni Pair-wise Comparisons were used to evaluate changes in the dependent variables used to describe stability and balance (sway velocity, turn sway, speed, and turn time). Measures of static postural stability and dynamic balance were similar for the three groups prior to training. Following the different exercise interventions, sway velocity on firm and foam surfaces (mCTSIB) with eyes closed (p < 0.05) increased for the Ballates group while the other two exercise groups either maintained or decreased their sway velocity following the training, therefore suggesting that these two groups either maintained or improved their balance. There were significant improvements in speed during the TW test (p < 0.01), and turn time (p < 0.01) and sway (p < 0.05) during the SQT test for each of the three groups. In general, all three training programs improved dynamic balance, however, step aerobics and walking programs resulted in be better improvements in postural stability or static balance when compared to the Ballates program.

Key Points

• Exercise training can improve balance
• Need to consider both static and dynamic aspects of balance individually
• Improved balance can reduce the risk of fall

Key words: Exercise intervention, static balance, dynamic balance, aging     

Effects of a Combined Aerobic and Strength Training Program in Youth Patients with Acute Lymphoblastic Leukemia

Cure rates of youth with Acute Lymphoblastic Leukemia (ALL) have increased in the past decades, but survivor’s quality of life and physical fitness has become a growing concern. Although previous reports showed that resistance training is feasible and effective, we hypothesized that a more intense exercise program would also be feasible, but more beneficial than low- to moderate-intensity training programs. We aimed to examine the effects of an exercise program combining high-intensity resistance exercises and moderate-intensity aerobic exercises in young patients undergoing treatment for ALL. A quasi-experimental study was conducted. The patients (n = 6; 5-16 years of age) underwent a 12-week intra-hospital training program involving high-intensity strength exercises and aerobic exercise at 70% of the peak oxygen consumption. At baseline and after 12 weeks, we assessed sub-maximal strength (10 repetition-maximum), quality of life and possible adverse effects. A significant improvement was observed in the sub maximal strength for bench press (71%), lat pull down (50%), leg press (73%) and leg extension (64%) as a result of the training (p < 0.01). The parents’ evaluations of their children’s quality of life revealed an improvement in fatigue and general quality of life, but the children’s self-reported quality of life was not changed. No adverse effects occurred. A 12-week in-hospital training program including high-intensity resistance exercises promotes marked strength improvements in patients during the maintenance phase of the treatment for Acute Lymphoblastic Leukemia without side-effects. Parents’ evaluations of their children revealed an improvement in the quality of life.

Key points

• Patients with ALL present low muscle strength and poor quality of life.
• High-intensity resistance exercises combined with moderate-intensity aerobic exercise improved muscle strength and quality of life during the maintenance phase of ALL treatment.
• The exercise training program seemed to be tolerable and safe in ALL patients.

Key words: Acute lymphoblastic leukemia, child, strength training, pediatrics, quality of life     

Effects of Upper Body Eccentric versus Concentric Strength Training and Detraining on Maximal Force,Muscle Activation,Hypertrophy and Serum Hormones in Women

Effects of eccentric (ECC) versus concentric (CON) strength training of the upper body performed twice a week for 10 weeks followed by detraining for five weeks on maximal force, muscle activation, muscle mass and serum hormone concentrations were investigated in young women (n = 11 and n = 12). One-repetition bench press (1RM), maximal isometric force and surface electromyography (EMG) of triceps brachii (TB), anterior deltoid (AD) and pectoralis major (PM), cross-sectional area (CSA) of TB (Long (LoH) and Lateral Head (LaH)) and thickness of PM, as well as serum concentrations of free testosterone, cortisol, follicle-stimulating hormone, estradiol and sex hormone-binding globulin were measured. ECC and CON training led to increases of 17.2 ± 11.3% (p < 0.001) and 13.1 ± 5.7% (p < 0.001) in 1RM followed by decreases of -6.6 ± 3.6% (p < 0.01) and -8.0 ± 4.5% (p < 0.001) during detraining, respectively. Isometric force increased in ECC by 11.4 ± 9.6 % (p < 0.05) from week 5 to 10, while the change in CON by 3.9±6.8% was not significant and a between group difference was noted (p < 0.05). Maximal total integrated EMG of trained muscles increased only in the whole subject group (p < 0.05). CSA of TB (LoH) increased in ECC by 8.7 ± 8.0% (p < 0.001) and in CON by 3.4 ± 1.6% (p < 0.01) and differed between groups (p < 0.05), and CSA of TB (LaH) in ECC by 15.7 ± 8.0% (p < 0.001) and CON by 9.7 ± 6.6% (p < 0.001). PM thickness increased in ECC by 17.7 ± 10.9% (p < 0.001) and CON by 14.0 ± 5.9% (p < 0.001). Total muscle sum value (LoH + LaH + PM) increased in ECC by 12.4 ± 6.9% (p < 0.001) and in CON by 7.1 ± 2.9% (p < 0.001) differing between groups (p < 0.05) and decreased during detraining in ECC by -6.5 ± 4.3% (p < 0.001) and CON by -6.1 ± 2.8% (p < 0.001). The post detraining combined sum value of CSA and thickness was in ECC higher (p < 0.05) than at pre training. No changes were detected in serum hormone concentrations, but baseline free testosterone levels in the ECC and CON group combined correlated with changes in 1RM (r = 0.520, p < 0.016) during training. Large neuromuscular adaptations of the upper body occurred in women during ECC, and CON training in 10 weeks. Isometric force increased only in response to ECC, and total muscle sum value increased more during ECC than CON training. However, no changes occurred in serum hormones, but individual serum-free testosterone baseline concentrations correlated with changes in 1RM during strength training in the entire group. Both groups showed significant decreases in neuromuscular performance and muscle mass during detraining, while post detraining muscle sum value was only in ECC significantly higher than at pre training. Key points

• Maximal eccentric and concentric strength training in women for 10 weeks (only twice a week) led to great gains in dynamic strength of upper body.
• Upper body muscle mass increased more after eccentric than concentric strength training.
• During detraining for 5 weeks both groups showed decreases in strength and muscle mass.
• However, post-detraining combined sum muscle mass value was only in ECC higher than at pre-training.

Key words: Muscle force, training, EMG, mass, females, testosterone     

The Effect of Structured Exercise Intervention on Intensity and Volume of Total Physical Activity

This study aimed to investigate the effects of a 12-week structured exercise intervention on total physical activity and its subcategories. Twenty-three overweight or obese middle aged men with impaired glucose regulation were randomized into a 12-week Nordic walking group, a power-type resistance training group, and a non-exercise control group. Physical activity was measured with questionnaires before the intervention (1–4 weeks) and during the intervention (1–12 weeks) and was expressed in metabolic equivalents of task. No significant change in the volume of total physical activity between or within the groups was observed (p > 0.050). The volume of total leisure-time physical activity (structured exercises + non-structured leisure-time physical activity) increased significantly in the Nordic walking group (p < 0.050) but not in the resistance training group (p > 0.050) compared to the control group. In both exercise groups increase in the weekly volume of total leisure-time physical activity was inversely associated with the volume of non-leisure-time physical activities. In conclusion, structured exercise intervention did not increase the volume of total physical activity. Albeit, endurance training can increase the volume of high intensity physical activities, however it is associated with compensatory decrease in lower intensity physical activities. To achieve effective personalized exercise program, individuality in compensatory behavior should be recognised.

Key Points

• Structured NW or RT training does not increase the volume of total physical activity.
• NW intervention can increase the volume of higher intensity activities.
• The increased in volume of LTPA induced by the structured NW and RT interventions was associated with the decreased volume of NLTPA.

Key words: Nordic walking, resistance training, energy expenditure, thermogenesis, glucose intolerance     

A Multi-Station Proprioceptive Exercise Program in Patients with Bilateral Knee Osteoarthrosis: Functional Capacity,Pain and Sensoriomotor Function. A Randomized Controlled Trial

We investigated the effects of a multi-station proprioceptive exercise program on functional capacity, perceived knee pain, and sensoriomotor function. Twenty-two patients (aged 41-75 years) with grade 2-3 bilateral knee osteoarthrosis were randomly assigned to two groups: treatment (TR; n = 12) and non-treatment (NONTR; n = 10). TR performed 11 different balance/coordination and proprioception exercises, twice a week for 6 weeks. Functional capacity and perceived knee pain during rest and physical activity was measured. Also knee position sense, kinaesthesia, postural control, isometric and isokinetic knee strength (at 60, 120 and 180°·s^-1) measures were taken at baseline and after 6 weeks of training. There was no significant difference in any of the tested variables between TR and NONTR before the intervention period. In TR perceived knee pain during daily activities and functional tests was lessened following the exercise program (p < 0.05). Perceived knee pain was also lower in TR vs. NONTR after training (p < 0.05). The time for rising from a chair, stair climbing and descending improved in TR (p < 0.05) and these values were faster compared with NONTR after training (p < 0.05). Joint position sense (degrees) for active and passive tests and for weight bearing tests improved in TR (p < 0.05) and the values were lower compared with NONTR after training (p < 0.05). Postural control (‘eyes closed’) also improved for single leg and tandem tests in TR (p < 0.01) and these values were higher compared with NONTR after training. The isometric quadriceps strength of TR improved (p < 0.05) but the values were not significantly different compared with NONTR after training. There was no change in isokinetic strength for TR and NONTR after the training period. The results suggest that using a multi-station proprioceptive exercise program it is possible to improve postural control, functional capacity and decrease perceived knee pain in patients with bilateral knee osteoarthrosis.

Key Points

• It is possible to improve postural control, functional capacity and decrease perceived knee pain in patients with bilateral knee osteoarthrosis with a pure proprioceptive/ balance exercise program used in the present study.
• The exercise regime used in the present study was as effective as previous studies, but of much shorter duration and utilized unsophisticated, inexpensive equipment which is available in most physiotherapy departments.
• Therefore, the incorporation of this exercise program into clinical practice is readily feasible.

Key Words: Osteoarthrosis, proprioception, balance, perceived knee pain, function     

Circuit Resistance Exercise Improves Glycemic Control and Adipokines in Females with Type 2 Diabetes Mellitus

The aim of study was to evaluate whether circuit resistance exercise (CE) improves glycemic control and adipokine levels in comparison with walking exercise (WE) in 15 adult postmenopausal Korean females with type 2 diabetes mellitus (T2DM). The participants were randomly assigned to either the CE or WE group. Subjects exercised for 1 h, three times per week for 12 weeks. The parameters measured were body composition, respiratory rate, blood glucose, insulin and adipokines. The body composition of the CE group showed a significant reduction (all p < 0.05) in body weight, body mass index (BMI), and percentage of body fat and a significant increase in muscle mass. Respiratory function was also significantly increased in the CE group. Additionally, hemoglobin A1c (HbA1c) changed favorably in the CE group, as were the concentrations of adipokines such as retinol binding protein 4 (RBP-4) (p < 0.05), adiponectin (p < 0.01), and monocyte chemoattractant protein-1 (MCP-1) (p < 0.01). In addition, significant correlations with CE were evident for homeostatic model assessment insulin resistance (HOMA-IR) and glucose (r = 0.69, p < 0.001), muscle mass and glucose (r = 0.45, p < 0.05), and muscle mass and HbA1c (r = 0.39, p < 0.05). The beneficial effects of CE include the development of muscle mass, which effectively increases glucose use and reduces the amount of insulin required. Thus, our results suggest that CE improves glycemic control and adipokines resulting from incrementally increased muscle mass and reductions of body weight, BMI and percentage of body fat for T2DM postmenopausal Korean women.

Key points

• CE-induced weight loss and muscle mass increment increases the level of adiponectin secreted by adipocytes due to heightened glucose utilization and fat oxidation.
• Aerobic exercise decreases body weight, fat and adipokines in high intensity and frequency, while resistance exercise decreases these parameters in low intensity, time and frequency.
• CE can improves glycemic control and adipokines resulting from reduction of body fat postmenopausal Korean women with T2DM.

Key words: Circuit resistance exercise, walking exercise, glycemic control, adipokines, type 2 diabetes.     

Exercise Training Improves Cardiovascular Autonomic Activity and Attenuates Renal Damage in Spontaneously Hypertensive Rats

Experiments were performed to determine the influence of exercise training by swimming on cardiovascular autonomic control and renal morphology in spontaneously hypertensive rats (SHR) and Wystar-Kyoto (WKY) rats. Sedentary normotensive (SN), trained normotensive (TN), sedentary hypertensive (SH), and trained hypertensive (TH) rats were included in this study. Arterial pressure (AP), heart rate (HR), means of power spectral analysis of HR (HRV) and systolic AP variability (SAPV) were recorded in baseline conditions. Following, the HR baroreflex and autonomic tonus control were assessed. At the end, all animals were euthanized and their kidneys were excised to evaluate renal damage. Resting bradycardia was observed in TH and TN rats compared with their respective sedentary animals (p < 0.05). Exercise training attenuated AP in TH vs. SH (p < 0.001). The LF component of HRV and SAPV were lower in TH than SH (p < 0.05). The LF/HF relation was lower in TH than SH and SN (p < 0.05). TN and TH rats showed a sympathetic tonus reduction in comparison to SN and SH rats (p < 0.001). The TH presented an increased vagal tonus compared to SH (p < 0.05). Exercise training improved baroreflex control of HR in TH group versus SH (p < 0.05). The TH showed a lower number of sclerotic glomeruli compared to SH (p < 0.005). The exercise training decrease the glomerular indexes in TN and TH (p < 0.05). Further analysis showed a significant correlation between sympathetic nervous activity and AP levels (p < 0.05). A positive association was also found between sympathetic nervous activity and glomerular index (p < 0.05). Therefore, the exercise training reduces AP and attenuates renal damage. In addition, the attenuation of renal injury was associated with lower sympathetic activity. These findings strongly suggest that exercise training may be a therapeutic tool for improving structure and renal function in hypertensive individuals.

Key points

• Endurance training.
• Decrease of the sympathetic activity.
• Attenuation of renal injury.
• Decrease of blood pressure in SHR.

Key words: Exercise training, hypertension, cardiovascular autonomic dysfunction, glomerulosclerosis, renal damage.     

Effects of Aging on Perceived Exertion and Pain During Arm Cranking in Women 70 to 80 YEARS OLD

The aim of this study was to examine the effects of aging on perceived exertion (PE) and perceived arm pain (PaP) at the end of a maximal graded arm test in 70- to 80-year -old women. Twelve healthy young (mean age 22.9 ± 3.3 years), and 12 healthy elderly (mean age 74.6 ± 3.7 years) women performed a maximal graded test (GXT) on an arm crank ergometer until exhaustion. The results revealed no significant difference between both groups concerning PE (p > 0.05; Effect Size = 0.62) and when heart rate (HR) was expressed as a theoretical maximal heart rate (THRmax) (p > 0.05; Effect Size = 0.17). Nevertheless, PaP was significantly lower (p < 0.05; Effect Size = 2.95) in the elderly compared to the young group. In conclusion, these results suggest that, at the end of GXT, PE is not influenced, whereas PaP may be altered by aging of the women tested in the present study. Therefore, it appears difficult to use PaP in these elderly women to regulate exercise intensity during a training program.

Key Points

• At the end of a maximal graded arm test, perceived exertion is not influenced, whereas perceived arm pain may be altered by aging.
• It appears difficult to use perceived arm pain in elderly women to regulate exercise intensity during a training program.

Key words: CR 10, elderly, pain, exercise     

The Effects of Aerobic Exercise on Skeletal Muscle Metabolism,Morphology and in Situ Endurance in Diabetic Rats

The effects of aerobic exercise training on skeletal muscle endurance capacity were examined in diabetic rats in situ. Moderate diabetes was induced by iv injection of streptozotocin and an exercise training program on a treadmill was carried out for 8 weeks. The animals randomly assigned to one of the four experimental groups: control-sedentary (CS), control-exercise (CE), diabetic-sedentary (DS) or diabetic-exercise (DE). The changes in the muscle endurance capacity were evaluated through the square wave impulses (supramaximal) of 0.2-ms duration at 1 Hz in the in situ gastrocnemius-soleus muscle complex. Muscle was stimulated continuously until tension development reduced to the half of this maximal value. Time interval between the beginning and the end of stimulation period is defined as contraction duration. Following the training period, blood glucose level reduced significantly in the DE group compared to DS group (p < 0.05). The soles muscle citrate synthase activity was increased significantly in both of the trained groups compared to sedentary animals (p < 0.05). Fatigued muscle lactate values were not significantly different from each other. Ultrastractural abnormality of the skeletal muscle in DS group disappeared with training. Presence of increased lipid droplets, mitochondria clusters and glycogen accumulation was observed in the skeletal muscle of DE group. The contraction duration was longer in the DE group than others (p < 0.001). Fatigue resistance of exercised diabetic animals may be explained by increased intramyocellular lipid droplets, high blood glucose level and muscle citrate synthase activity.

Key Points

• Aerobic training of diabetic animals increased the endurance capacity.
• Presence of abnormal ultrastructural alterations with diabetes disaapered with regular training.
• Increased intramyocelluler lipid droplets, high blood glucose level with citrate synthase activity may explain this finding.

Key Words: Training, citrate synthase, muscle endurance, ultrastructure, diabetes     

Effect of Phlebodium Decumanum on the Immune Response Induced by Training in Sedentary University Students

Exercise training is considered a good model to provoke different degrees of immune dysfunction affecting physical performance and some physiological responses related to oxidative stress and low grade inflammation. Phlebodium decumanum is a polypodiaceae may induce shown immunomodulating effects, specifically directed to the release of proinflammatory cytokines by macrophages in response to various stimuli, as reported different in vitro studies. The aim of this study was to evaluate the modulating effect of phlebodium decumanum, on the immune response induced by physical exercise. Thirty-one subjects (males only) were randomly divided into two groups: Group PD (n = 18); age: 22.1 ± 1.81, weight 74.21 ± 8.74 kg) that was treated with phlebodium decumanum; Group P (n = 13); age: 22.5 ± 1.63, weight 78 ± 12.5 kg) that was treated with a placebo. Before and after one month training program performed by both groups (three times a week), the following performance parameters and immune response variables were measured: Dynamic Maximum Force; Interval-Training; Tennis test; pro-inflammatory (TNF , IL6) and anti-inflammatory (TNFα-IIrs, IL1-ra) cytokines levels. Data were statistically analyzed with Mann- Whitney U test and Wilcoxon paired test (p < 0.05). Statistically significant differences were recorded within groups before and after the training program. PD group showed a significant improvement in the performance parameters (Strength Muscle Test: dorsal: p < 0.002; deltoids: p < 0.03; and pectorals: p < 0.07; Interval Training: p < 0.06; Tennis Test: p < 0.02). Cytokine levels resulted in a more positive profile in the PD group rather than in the P group, in which higher levels of IL-6 (p < 0.02) and a reduction of TNF-IIrs (p < 0.003) and IL1-ra (p < 0.03) were recorded. In this study the use of phlebodium decumanum demonstrated beneficial effects in the modulation of the immune response during physical performance.

Key points

• Practicing sport or physical activity of medium-high intensity three times a week during 4 weeks induces changes in immune response indicators levels;
• The assumption of phlebodium decumanum induced a reduction in pro-inflammatory cytokines levels and a higher concentration of anti-inflammatory cytokines.
• Anti-inflammatory cytokines have a protective and modulating effect on the immune response.

Key words: Physical exercise, inmunomodulation, TNFα, IL6, TNF-IIrs, IL1-ra     

Obesity-related cardiovascular risk factors after long- term resistance training and ginger supplementation

Obesity and its metabolic consequences are major risk factors for cardiovascular morbidity and mortality. However, lifestyle interventions, including exercise training and dietary components may decrease cardiovascular risk. Hence, this study was conducted to assess the effects of ginger supplementation and progressive resistance training on some cardiovascular risk factors in obese men. In a randomized double-blind design, 32 obese Iranian men (BMI ≥ 30) were assigned in to one of four groups: Placebo (PL, n = 8); ginger group (GI, n = 8) that consumed 1 gr ginger/d for 10 wk; resistance training plus placebo (RTPL, n = 8); and 1gr ginger plus resistance exercise (RTGI, n = 8). Progressive resistance training was performed three days per week for 10 weeks and included eight exercises. At baseline and after 10 weeks, body composition and anthropometric indices were measured. To identify other risk factors, venous blood samples were obtained before and 48-72 hours after the last training session for measurement of blood lipids (LDL-C, HDL-C, TG), systemic inflammation (CRP), and insulin resistance (HOMA-IR). After 10 weeks both RTGI and RTPL groups showed significant decreases in waist circumference (WC), waist-to-hip ratio (WHR), body fat percent, body fat mass, total cholesterol, and insulin resistance (p < 0.05) and a significant increase in fat free mass (FFM) (p < 0.05), while it remained unchanged in PL and GI. Further, significant decreases in the mean values of CRP were observed in all groups except PL (p < 0.05). Our results reveal that resistance training is an effective therapeutic strategy to reduce cardiovascular risk in obese Iranian men. Further, ginger supplementation alone or in combination with resistance training, also reduces chronic inflammation. However more research on the efficacy of this supplement to reduce cardiovascular risk in humans is required.

Key points

• Long- term resistance training reduced cardiovascular risk factors in obese men.
• Ginger supplementation can also decrease chronic low grade inflammation in obese men.
• More researches are warranted to elicit the effects of these interventions on cardiovascular risk factors in humans.

Key words: Cardiovascular risk factors, resistance training, ginger supplementation     

Development Of a Field Test for Evaluating Aerobic Fitness in Middle-Aged Adults: Validity of a 15-M Incremental Shuttle Walk and Run Test

The purpose of this study was to develop a standardized and externally paced field test (15-m Incremental Shuttle Walk and Run Test [15mISWRT]), incorporating an incremental and progressive structure, to assess aerobic fitness in middle-aged adults. 68 middle-aged men performed three tests in random order between one to two week intervals: 15-m ISWRT, cardiopulmonary exercise test (CPX), and 1500-m fast walk. Variables evaluated were 15-m ISWRT performance (distance completed), VO₂max measured by CPX, 1500-m fast walk performance (walking time), and HR response in 15-m ISWRT and 1500-m fast walk. Validity of the 15-m ISWRT was tested by comparing the associations among the 15-m ISWRT performance, VO₂max and the 1500-m fast walk performance. Changes in HR response during the 15-m ISWRT and the 1500-m fast walk were also compared. Correlations between each variable were as follows: the correlation between 15- m ISWRT performance and VO₂max was very high, r = 0.86 (p < 0.01), the correlation between the 1500-m fast walk and VO₂max was r = −0.51 (p < 0.01). HR response during the 15-m ISWRT gently increased initially, whereas HR response during the 1500-m fast walk rapidly increased from the start. In conclusion, our findings indicate that the 15-m ISWRT is valid and safe for evaluating VO₂max in middle-aged adults.

Key points

• The 15-m ISWRT is valid and safe for evaluating VO₂max in middle-aged adults.
• In comparison with the 1500-m fast walk, the 15-m ISWRT may be a more favourable field-based assessment of aerobic fitness in the middle-aged adults.
• The 15-m ISWRT could become a valid means for evaluating aerobic fitness as an alternative to CPX in institutions and situations where CPX is difficult to implement.

Key words: Maximal oxygen uptake, heart rate, 20m shuttle run test, shuttle walking test, cardiopulmonary exercise test