Breathing Motion Pattern in Cyclists: Role of Inferior against Superior Thorax Compartment

The thoracoabdominal breathing motion pattern is being considered in sports training because of its contribution, along with other physiological adaptations, to overall performance. We examined whether and how experience with cycling training modifies the thoracoabdominal motion patterns. We utilized optoelectronic plethysmography to monitor ten trained male cyclists and compared them to ten physically active male participants performing breathing maneuvers. Cyclists then participated in a self-paced time trial to explore the similarity between that observed during resting breathing. From the 3D coordinates of 32 markers positioned on each participant's trunk, we calculated the percentage of contribution of the superior thorax, inferior thorax, and abdomen and the correlation coefficient among these compartments. During the rest maneuvers, the cyclists showed a thoracoabdominal motion pattern characterized by an increased role of the inferior thorax relative to the superior thorax (26.69±5.88%, 34.93±5.03%; p=0.002, respectively), in contrast to the control group (26.69±5.88%; 25.71±6.04%, p=0.4, respectively). In addition, the inferior thorax showed higher coordination in phase with the abdomen. Furthermore, the results of the time trial test underscored the same pattern found in cyclists breathing at rest, suggesting that the development of a permanent modification in respiratory mechanics may be associated with cycling practice.

A Cardiopulmonary Exercise Testing for Prescribing High-Intensity Interval Training Sessions with Elastic Resistance

This study aims to analyze the agreement of cardiopulmonary variables between a cardiopulmonary exercise test with elastic resistance (CPxEL) and high-intensity interval exercise with elastic resistance (EL-HIIE).

METHODS

Twenty-two physically independent participants were recruited. Visit one consisted of conducting a health survey and anthropometric assessment. On visit two, the participants performed CPxEL. After seven days, on visit three, the participants performed EL-HIIE. The CPxEL was carried out on a rubber mat demarcated by lines representing eight stages. The test consisted of alternating back and forth steps against elastic resistance. The increments were performed at a rate of one stage per minute, following a cadence controlled by a metronome calibrated by beats per minute (bpm). The EL-HIIE was performed at the stage corresponding to an intensity of ~85% VO2max, as determined by CPxEL. The EL-HIIE consisted of 10 × 1 min (work):1 min (passive rest), with a cadence of 200 bpm. Cardiopulmonary parameters, heart rate (HR), and oxygen consumption (VO2) were measured during exercise. Bland-Altman was applied to analyze the agreement between the HR and VO2 found in EL-HIIE and the values prescribed by CPxEL (~85-90% VO2max).

RESULTS

The HRpeak and VO2peak in the EL-HIIE showed good agreement with the VO2CPxEL and HRCPxEL values, showing an average difference of (-1.7 mL·kg-1·min-1) and (0.3 bpm).

CONCLUSIONS

The results of the present study demonstrate the agreement of cardiopulmonary variables between the CPxEL and the EL-HIIE. Therefore, for a more specific prescription of EL-HIIE intensity, CPxEL can be used.

Acute Cardiopulmonary Response of High-Intensity Interval Training with Elastic Resistance vs. High-Intensity Interval Training on a Treadmill in Healthy Adults

This study aims to describe and compare cardiopulmonary and subjective responses during high-intensity interval training with elastic resistance (EL-HIIT) and traditional high-intensity interval training (HIIT) sessions. Twenty-two healthy adults (27.6 ± 4.4 years) performed an EL-HIIT and a HIIT protocol consisting of 10 × 1 min at ~85% V·O2max prescribed by cardiopulmonary-specific tests. Pulmonary parameters, heart rate (HR), blood lactate, and rate of perceived exertion (RPE) were measured during exercise. Paired t-test and Cohen's d effect size were used to compare peak and average values. Two-way repeated measures ANOVA and mixed model with Bonferroni's post hoc test were used to compare each bout during the session. The EL-HIIT session showed higher peak and average values of HR, ventilation (V·E), relative and absolute oxygen uptake (V·O2), carbon dioxide production (V·CO2), and RPE than HIIT (p < 0.05). The effect size (ES) comparing HIIT and EL-HIIT was large for HR, V·E, and lactate (≥0.8) in peak values. Comparing each bout between HIIT and EL-HIIT, no difference was found in peak values (p > 0.05) during the session (excluding baseline, warm-up, and recovery). EL-HIIT presented a more pronounced cardiopulmonary and subjective response than HIIT.

Impaired Cardiovascular Parameters in Resistance Training Practitioners Who Take Ergogenic Aids

BACKGROUND

Although there are studies on blood pressure (BP) and autonomic cardiac control (ACC) impairments caused by ergogenic aids, research has scarcely addressed this analysis during sleep. This study analyzed BP and ACC during sleep and wake periods in three groups of resistance training (RT) practitioners: ergogenic aid non-users, thermogenic supplement (TS) self-users, and anabolic-androgenic steroid (AAS) self-users.

METHODS

RT practitioners were selected for the Control Group (CG; n = 15), TS self-users Group (TSG; n = 15), and AAS self-users Group (AASG; n = 15). All individuals underwent cardiovascular Holter monitoring (BP, ACC) during sleep and wake periods.

RESULTS

The maximum systolic BP (SBP) during sleep was higher in AASG (p < 0.01) than CG (p < 0.001). CG had lower mean diastolic BP (DBP) than TSG (p < 0.01) and lower mean SBP (p = 0.009) than the other groups. Additionally, CG had higher values (p < 0.01) than TSG and AASG for SDNN and pNN50 during sleep. HF, LF, and LF/HF ratio values during sleep were statistically different in CG (p < 0.001) from the other groups.

CONCLUSIONS

Our findings demonstrate that high doses of TS and AAS can impair cardiovascular parameters during sleep in RT practitioners who take ergogenic aids.

Is There Agreement and Precision between Heart Rate Variability, Ventilatory, and Lactate Thresholds in Healthy Adults?

This study aims to analyze the agreement and precision between heart rate variability thresholds (HRVT1/2) with ventilatory and lactate thresholds 1 and 2 (VT1/2 and LT1/2) on a treadmill. Thirty-four male students were recruited. Day 1 consisted of conducting a health survey, anthropometrics, and Cardiopulmonary Exercise Test (CPx). On Day 2, after 48 h, a second incremental test was performed, the Cardiopulmonary Stepwise Exercise Test consisting of 3 min stages (CPxS), to determine VT1/2, LT1/2, and HRVT1/2. One-way repeated-measures ANOVA and effect size (η_p²) were used, followed by Sidak's post hoc. The Coefficient of Variation (CV) and Typical Error (TE) were applied to verify the precision. Bland Altman and the Intraclass Correlation Coefficient (ICC) were applied to confirm the agreement. HRVT1 showed different values compared to LT1 (lactate, RER, and R-R interval) and VT1 (V̇E, RER, V̇CO₂, and HR). No differences were found in threshold 2 (T2) between LT2, VT2, and HRVT2. No difference was found in speed and V̇O₂ for T1 and T2. The precision was low to T1 (CV > 12% and TE > 10%) and good to T2 (CV < 12% and TE < 10%). The agreement was good to fair in threshold 1 (VT1, LT1, HRVT1) and excellent to good in T2 (VT1, LT1, HRVT1). HRVT1 is not a valid method (low precision) when using this protocol to estimate LT1 and VT1. However, HRVT2 is a valid and noninvasive method that can estimate LT2 and VT2, showing good agreement and precision in healthy adults.

Profile of blood pressure and glycemic responses after interval exercise in older women attending (in) a public health physical activity program

BACKGROUND

and purpose: Interval exercise causes a positive impact on health status. Our aim was to evaluate the effects of a feasible and low-cost interval exercise on blood pressure and glycemic responses in people with controlled systemic arterial hypertension.

METHODS

Thirteen women with hypertension (HG; age: 60.2 ± 2.8 years) and 11 without hypertension (CG; age: 54.4 ± 3.8 years) were recruited. Groups performed one session of interval exercise with elastic resistance (10 series of 1:1 min/effort:rest).

RESULTS

There were slight reductions of absolute systolic blood pressure values for HG at 10, 30, and 60 min (4, 9, and 8 mmHg, respectively) at post-compared to pre-exercise. Glycemia was reduced (respectively, 17.6%, 17.6%, 19.4%, and 23.1%; p < 0.05) at pre-exercise vs. 0 min and 10, 30, and 60 min post-exercise for the HG.

CONCLUSION

A single session of a feasible and low-cost interval exercise modifies and promotes significant clinical effects in blood pressure and glycemic levels in female older adults with and without hypertension.

A validation study of a smartphone application for heart rate variability assessment in asymptomatic adults

BACKGROUND

Assessment of heart rate variability (HRV) is an effective non-invasive tool to obtain data on cardiac autonomic modulation and may be assessed by a range of devices, including mobile applications. Objective: This study aimed to validate a smartphone application by comparing the R-R intervals (RRi) obtained by the app with a classic electrocardiogram (ECG)-derived reference condition Methods: Fifteen asymptomatic adults (24.9±3.4 years) underwent an orthostatic challenge during which RRi were simultaneously recorded by a freeware smartphone application and by an ECG recorder. Pearson correlation coefficients (r) and coefficients of determination (r ²) were calculated to determine the degree of association between the two electronic devices. Two-way repeated measures analysis of variance and Bland-Altman analysis were used to calculate the measurement consistency and agreement, respectively, between the two methods. Effect size was also used to estimate the magnitude of the differences.

RESULTS

The number of RRi from asymptomatic adults recorded by the ECG and by the free smartphone application was similar at rest in supine position (13,149 vs. 13,157; P = 0.432) and during orthostatic challenge (10,666 vs. 10,664 P = 0.532). RRi in milliseconds from both devices presented a near perfect correlation in the supine position (r = 0.999; Confidence Interval [CI] at 95%: 0.999-0.999; P < 0.0001) and during orthostatic challenge (r = 0.988; 95% CI: 0.988-0.989; P < 0.0001). A negative bias of -0.526 milliseconds (95% limits of agreement [LoA] from -4.319 to 3.266 milliseconds) was observed in supine position between ECG and the smartphone application. On the other hand, a positive bias of 0.077 milliseconds (95% LoA from -10.090 to 10.240 milliseconds) during the orthostatic challenge was observed.

CONCLUSIONS

Our results cross-validated a freeware smartphone application with the ECG-derived reference condition for asymptomatic adults at rest in the supine position and during orthostatic challenge.

Resistance training promotes reduction in Visceral Adiposity without improvements in Cardiomyocyte Contractility and Calcium handling in Obese Rats

Resistance training (RT) improves the cardiomyocyte calcium (Ca²⁺) cycling during excitation-contraction coupling. However, the role of RT in cardiomyocyte contractile function associated with Ca²⁺ handling in obesity is unclear. Wistar rats were distributed into four groups: control, sedentary obese, control plus RT, and obesity plus RT. The 10-wk RT protocol was used (4-5 vertical ladder climbs, 60-second interval, 3× a week, 50-100% of maximum load). Metabolic, hormonal, cardiovascular and biochemical parameters were determined. Reduced leptin levels, epididymal, retroperitoneal and visceral fat pads, lower body fat, and adiposity index were observed in RT. Obesity promoted elevation of collagen, but RT did not promote modifications of LV collagen in ObRT. RT induced elevation in maximum rates of contraction and relaxation, and reduction of time to 50% relaxation. ObRT group did not present improvement in the cardiomyocyte contractile function in comparison to Ob group. Reduced cardiac PLB serine¹⁶ phosphorylation (pPLB Ser¹⁶) and pPLB Ser¹⁶/PLB ratio with no alterations in sarcoplasmic reticulum Ca²⁺ ATPase (SERCA2a) and phospholamban (PLB) expression were observed in Ob groups. Resistance training improved body composition reduced fat pads and plasma leptin levels but did not promote positive alterations in cardiomyocyte contractile function, Ca²⁺ handling and phospholamban phosphorylation.

INFLUENCE OF CREATINE KINASE ON C-REACTIVE PROTEIN IN MUSCLE ADAPTATION

ABSTRACT Introduction Aging is a natural process and marked by changes and adaptations of both a biological and physiological nature. As regards adaptations, there are numerous works that address these responses following various types of training programs. Resistance training (RT) can be assessed by biochemical parameters such as creatine kinase (CK), which is a major marker of stress in the skeletal muscles. C-reactive protein (CRP) is a biochemical marker used to assess damage to the cardiac muscles. Objective To evaluate the influence of CK on CRP in elderly female subjects undergoing RT. Methods An experimental study was carried out with 10 elderly women (61 ± 1.8 years). Peripheral venous blood was collected for the CK and CRP analysis both before and 24 hours after 8 weeks of RT. Anthropometric measurements involved BMI (Body Mass Index), WHR (waist-to-hip ratio) and body composition. The RT involved combined series - Bi-Set. For statistical analysis, the Shapiro-Wilk normality test was conducted first and presented p >0.05, confirming the use of parametric tests. Group variables were presented as mean and standard deviation. To compare the load-dependent samples, the repeated measures one-way ANOVA was performed first, followed by Tukey’s post hoc test. For CK and CRP variables, we conducted the paired Student’s t-test for the timepoints pre- and post-eight weeks of RT along with the one-way ANOVA test, also conducting Tukey’s post-test when necessary. The level of significance was set at p ≤0.05. Results There was a statistically significant decrease in both serum CK and CRP, which indicated a reduction of 73.14% and 75%, respectively. Conclusion Long-term RT promoted influences among biomarkers assessed through skeletal muscle (CK) and cardiac muscle (CRP) damage, determining adaptation and muscle remodeling in any age group. Level of evidence II, Investigation of treatment results.

Effects of Resistance Training on Immunoinflammatory Response, TNF-Alpha Gene Expression, and Body Composition in Elderly Women

The aim of this study was to determine the effects of resistance training on the immunologic response, body composition, tumor necrosis factor-alpha (TNF-alpha) gene expression obtained from blood leukocytes, and the cytokines interleukin-6, TNF-alpha, and C-reactive protein (CRP), in the elderly women (mean age 63 ± 2 y). A randomized controlled trial was performed using a bi-set training method for eight weeks in nineteen elderly women. Peripheral blood samples were collected by puncture in pretraining (Pre) and posttraining (Post) moments. In the resistance training group, there was a statistically significant decrease from 38.43 ± 9.48 pg/mL to 11.76 ± 5.19 pg/mL (p=0.01) in the serum levels of interleukin-6. Considering serum levels of TNF-alpha, there was a statistically significant difference, comparing the resistance training group at Pre (66.27 ± 10.31 pg/mL) and Post (37.85 ± 9.05 pg/mL) moments (p=0.01). In molecular analysis of TNF-alpha gene expression, there was a statistically significant decrease (p=0.007) between Pre (0.010 ± 0.01 ng/ml) and Post (0.0002 ± 0.0001 ng/ml) moments. Among CRP data, in the resistance training group, there was a statistically significant reduction, between Pre (2.04 ± 0.32 mg/L) and Post (0.90 ± 0.22 mg/L) moments (p=0.001). In the Control group, there was no statistical significance between these two moments. Therefore, the resistance training demonstrated changes in the TNF-alpha gene expression in elderly women, as well as decreased serum levels of interleukin-6, TNF-alpha, and CRP. Such conditions may be related to immune modulation and anti-inflammatory effects, since resistance training releases cytokines, especially interleukin-6, which acts as a TNF-alpha antagonist during exercise.

Resistance training improves body composition and increases matrix metalloproteinase 2 activity in biceps and gastrocnemius muscles of diet-induced obese rats

OBJECTIVE

We investigated the influence of resistance training on body composition and matrix metalloproteinase 2 activity in skeletal muscles of rats fed a high-fat diet.

METHODS

Thirty-two Wistar rats were divided into four experimental groups (n = 8/each) according to diet and exercise status: Control (standard diet), Obese Control (high-fat diet), Resistance Training (standard diet) and Obese Resistance Training (high-fat diet) groups. Animals were fed a high-fat diet for 12 weeks to promote excessive weight gain. Resistance Training groups performed 12 weeks of training periods after this period in a vertical ladder three times/week. Fat percentage, fat-free mass and fat mass were assessed using dual-energy X-ray absorptiometry, and matrix metalloproteinase 2 activity in biceps and gastrocnemius muscles was analyzed using zymography.

RESULTS

Resistance training significantly reduced body and fat masses and fat percentages in both trained groups (p<0.05). The maximal carrying load between trained groups was not different, but relative force was higher in the Resistance Training group (p<0.05). Of note, increased matrix metalloproteinase 2 activity was noted in the tested muscles of both trained groups (p<0.05).

CONCLUSION

In conclusion, altered body composition and muscle matrix metalloproteinase 2 activity promoted by excessive weight gain were positively modified by resistance training.

Resistance training may concomitantly benefit body composition, blood pressure and muscle MMP-2 activity on the left ventricle of high-fat fed diet rats

OBJECTIVE

The purpose of this study was to evaluate the effect of resistance training (RT) on body composition, systolic and diastolic blood pressures (BP), and activity of muscle MMP-2 in the left ventricle of high-fat fed rats.

MATERIALS/METHODS

We have evaluated 32 male Wistar rats divided into four experimental groups (n=8/each) according to diet and exercise status: sedentary (SED; standard diet), sedentary obese (SED-OB; diet: 30% of fat), RT (RT; standard diet) and RT obese (RT-OB; diet: 30% of fat). After weaning (day 21), animals were subjected to the experimental diet according to their groups during 24 weeks. A 12-week strength-training period was used, during which the rats climbed a 1.1-m vertical ladder with weights attached to their tails. Sessions were performed three times/week (Mondays, Wednesdays and Fridays), with 4-9 climbs/session and 8-12 dynamic movements/climb.

RESULTS

RT induced higher muscle MMP-2 activity in the left ventricle in RT and RT-OB groups. Moreover, this study demonstrated that RT promoted lower body and fat masses, fat percentage, systolic and diastolic BPs and higher fat free mass in both trained groups.

CONCLUSION

RT increased muscle MMP-2 activity in the left ventricle, induced positive changes on body composition and lowered BPs in high-fat diet fed rats, suggesting that it may be a useful tool to prevent alterations induced by high-fat diet consumption.

Effects of ovariectomy and resistance training on oxidative stress markers in the rat liver

OBJECTIVE

The objective of this study was to assess the effects of resistance training on oxidative stress markers in the livers of ovariectomized rats.

METHOD

Adult Sprague-Dawley rats were divided into the following four groups (n = 8 per group): sham-operated sedentary, ovariectomized sedentary, sham-operated resistance training, and ovariectomized resistance training. During the resistance training period, the animals climbed a 1.1-m vertical ladder with weights attached to their tails; the sessions were conducted 3 times per week, with 4-9 climbs and 8-12 dynamic movements per climb. The oxidative stress was assessed by measuring the levels of reduced glutathione and oxidized glutathione, the enzymatic activity of catalase and superoxide dismutase, lipid peroxidation, vitamin E concentrations, and the gene expression of glutathione peroxidase.

RESULTS

The results showed significant reductions in the reduced glutathione/oxidized glutathione ratio (4.11±0.65 nmol/g tec), vitamin E concentration (55.36±11.11 nmol/g), and gene expression of glutathione peroxidase (0.49±0.16 arbitrary units) in the livers of ovariectomized rats compared with the livers of unovariectomized animals (5.71±0.71 nmol/g tec, 100.14±10.99 nmol/g, and 1.09±0.54 arbitrary units, respectively). Moreover, resistance training for 10 weeks was not able to reduce the oxidative stress in the livers of ovariectomized rats and induced negative changes in the hepatic anti-oxidative/oxidative balance.

CONCLUSION

Our findings indicate that the resistance training program used in this study was not able to attenuate the hepatic oxidative damage caused by ovariectomy and increased the hepatic oxidative stress.

Influence of upper-body exercise order on hormonal responses in trained men

The aim of this study was to examine acute hormonal responses after different sequences of an upper-body resistance-exercise session. Twenty men completed 2 sessions (3 sets; 70% 1-repetition maximum; 2 min passive rest between sets) of the same exercises in opposite sequences (larger to smaller vs. smaller to larger muscle-group exercises). Total testosterone (TT), free testosterone (FT), testosterone/cortisol (T/C) ratio, sex-hormone-binding globulin (SHBG), growth hormone (GH), and cortisol (C) concentrations were measured before and immediately after each sequence. The results indicate that the GH concentration increased after both sessions, but the increase was significantly greater (p < 0.05) after the sequence in which larger muscle-group exercises were performed prior to the smaller muscle-group exercises. No differences were observed between sessions for TT, FT, SHBG, C, or the T/C ratio at baseline or immediately after resistance exercise. These results indicate that performing larger muscle-group exercises first in an upper-body resistance-exercise session leads to a significantly greater GH response. This may have been due to the significantly greater exercise volume accomplished. In summary, the findings of this investigation support the common prescriptive recommendation to perform larger-muscle group exercises first during a resistance-exercise session.

The effects of exercise modalities on adiposity in obese rats

OBJECTIVE

The aim of the present study was to evaluate the effect of both swimming and resistance training on tumor necrosis factor-alpha and interleukin-10 expression, adipocyte area and lipid profiles in rats fed a high-fat diet.

METHODS

The study was conducted over an eight-week period on Wistar adult rats, who were divided into six groups as follows (n = 10 per group): sedentary chow diet, sedentary high-fat diet, swimming plus chow diet, swimming plus high-fat diet, resistance training plus chow diet, and resistance training plus high-fat diet. Rats in the resistance training groups climbed a vertical ladder with weights on their tails once every three days. The swimming groups swam for 60 minutes/day, five days/week.

RESULTS

The high-fat diet groups had higher body weights, a greater amount of adipose tissue, and higher tumor necrosis factor-alpha expression in the visceral adipose tissue. Furthermore, the high-fat diet promoted a negative change in the lipid profile. In the resistance training high-fat group, the tumor necrosis factor-alpha expression was lower than that in the swimming high-fat and sedentary high-fat groups. Moreover, smaller visceral and retroperitoneal adipocyte areas were found in the resistance training high-fat group than in the sedentary high-fat group. In the swimming high-fat group, the tumor necrosis factor-alpha expression was lower and the epididymal and retroperitoneal adipocyte areas were smaller compared with the sedentary high-fat group.

CONCLUSION

The results showed that both exercise modalities improved the lipid profile, adiposity and obesity-associated inflammation in rats, suggesting their use as an alternative to control the deleterious effects of a high-fat diet in humans.

Linear and daily undulating resistance training periodizations have differential beneficial effects in young sedentary women

The aim of this randomized controlled study was to verify the impact of a 12-weeks muscular endurance (ME) training of high repetitions (i. e., 15-30) with 2 different periodization models on body composition, maximal strength, muscular endurance and cardiorespiratory fitness. Twenty eight sedentary women aged 20-35 years were randomly assigned to: control (CON) (n=8), linear periodization (LP) (n=10) and daily undulating periodization (DUP) (n=10). LP and DUP models significantly improved body composition, maximal strength and ME. However, no significant changes were detected for cardiorespiratory fitness. LP showed a higher body fat loss (- 12.73%) compared to DUP (- 9.93%) (p=0.049), and systematically higher effect sizes (ES) when compared with DUP for maximal strength and cardiorespiratory fitness parameters (e. g. ES=0.53 for ventilatory threshold). In contrast, DUP exhibited a significantly (p=0.002) greater ME gain (129.43%) compared to LP (70.72%) in bench press, and greater ES in all exercises. It may be suggested that LP performed with a high number of repetitions may be considered an appropriate periodization model for untrained young women that would likely lead to the improvement of body composition and maximum strength performance, whereas DUP is more effective for the development of ME.

Different cardiovascular responses to a resistance training session in hypertensive women receiving propanolol compared with normotensive controls

The aim of the present study was to compare the responses of blood pressure, heart rate, and rate-pressure product of hypertensive women using beta-blockers with healthy controls during resistance exercise (by the end of the concentric phase of the contractions) and in the postexercise period (5 and 30 minutes after). Ten untrained normotensive women (N) and 10 mildly hypertensive females receiving 40 mg/day of propanolol (H) were selected. Three sets of 10 repetitions at 80% of 10 repetitions maximum with 30 s rest interval were performed on the leg press exercise. The H group exhibited lower systolic blood pressure after the second set compared with N. Heart rate and rate-pressure product were lower in H in all analyzed periods compared with N. Propanolol attenuates the cardiovascular response to a leg press resistance exercise in mildly hypertensive women.

Resistance training and glycogen content in ovariectomized rats

The aim of the present study was to investigate the effects of resistance training on glycogen content and muscle cross-sectional area (CSA) in ovariectomized rats. Wistar rats were divided into: sedentary; ovariectomized sedentary; resistance trained; and ovariectomized resistance trained. In the 12-week resistance training, the animals climbed a 1.1 m vertical ladder, 3 days per week, with 4-8 climbs. Cardiac, liver and muscle glycogen content was determined. After the 12-week resistance training period there was a higher hepatic and muscle glycogen content in the resistance training group compared with the other groups (p<0.01). CSA was higher in soleus for the resistance trained, ovariectomized resistance trained and sedentary compared with ovariectomized sedentary (p<0.05). Ovariectomy attenuated the increase in liver and muscle glycogen content, while soleus muscle cross-sectional area increased with resistance training, even in ovariectomized rats. Resistance training could be an important exercise to increase muscle function in situations of reduced estrogen and progesterone.

Immune parameters, symptoms of upper respiratory tract infections, and training-load indicators in volleyball athletes

Background

The control of immunological alterations becomes important during in-season training, as a result of increased incidence of infectious diseases, and may assist in avoiding interruptions to training due to illness.

Objective

The aim of the present study was to evaluate 28 weeks of chronic immune modulations in female volleyball athletes.

Methods

The sample was composed of twelve athletes aged 19.47 ± 2.49 years, height 1.78 ± 0.08 cm, and body mass 66.77 ± 7.8 kg. Leukocytes, individual immune cell count, interleukin (IL)-2, IL-6, and tumor necrosis factor (TNF)-α plasma cytokines were measured during the competitive period.

Results

Results revealed that immune variables were correlated with symptoms of upper respiratory tract infections and training-load indicators, indicating a possible marker of immune status. There was a statistically significant increase in total leukocytes, neutrophils, and monocyte count, a decrease in lymphocytes, and an increase in upper respiratory tract infection symptoms, with no change in IL-2, IL-6, and TNF-α. Correlations between subjective levels of tiredness, total leukocyte count, and neutrophils with upper respiratory tract infection symptoms were observed.

Conclusion

In conclusion, these correlations can represent important tools to access the immune status of an athlete during long training periods, preventing a possible immunosuppressive status.

Acute effect of resistance training volume on hormonal responses in trained men

AIM

The purpose of this study was to investigate the acute hormonal response to resistance training sessions with different volumes in men.

METHODS

Ten recreationally trained men (24.5±7.6 years; 76.2±9.2 kg; 175.6±1.5 cm; 24.5±5.5 kg/m(-2)) participated in the study. All subjects completed two experimental protocols with different volumes. The first protocol consisted of 3 sets at 80% of 6 RM and the second protocol was 3 sets at 80% of 12 RM with 2 minutes rest between sets and exercises, separated by seven days between them. The exercise order used was: barbell bench press, leg press, machine front lat-pull down, leg curl, shoulder abduction and leg extension. The blood variables analyzed were: testosterone, growth hormone (GH), cortisol and testosterone/cortisol ratio (T:C) before (Pre) and immediately after (Post) each exercise session.

RESULTS

The intra-groups comparison for testosterone and hGH revealed a significant increase in 80%-6RM and 80%-12RM. Cortisol levels was significantly higher in 80%-12RM and T:C ratio in 80% 6 RM when compared Pre and Post values. Inter-groups comparison showed higher hGH and cortisol levels and lower T:C ratio for 80% 12 RM. There was no statistically significant different between 80%-6RM and 80%-12RM for testosterone.

CONCLUSION

The present study confirms that the volume of resistance training can be an important factor in the modulation of acute hormonal responses.

Effects of resistance training on matrix metalloproteinase-2 activity and biomechanical and physical properties of bone in ovariectomized and intact rats

The purpose of this study was to investigate the influence of resistance training on the activity of matrix metalloproteinase (MMP)-2 and bone biomechanical properties in ovariectomized and intact rats. Forty-eight female rats were divided into two distinct groups, ovariectomized (OVX) and intact (Int), which were subdivided into three similar subgroups: sedentary, acute exercise and chronic exercise. Rats performed a resistance training for 12 weeks in which animals climbed a vertical ladder of 1.1 m with weights attached to their tails. Sessions were performed with an interval of 3, 4-9 and 8-12 days scaled dynamic movements of climbing. Biomechanical and physical analyses were performed using a universal testing machine, and MMP-2 activity analysis by zymography. Bone density (BD), mineral density (MD), maximum load and fracture load was reduced in sedentary and acute exercise OVX groups compared with the sedentary intact group (P<0.05); in contrast, chronically trained groups (OVX and Int) showed a significant increase in BD, MD and fracture load compared with all the other groups. MMP-2 activity in chronically trained groups also showed a significant increase, while the sedentary OVX group showed a decrease in MMP-2 activity compared with the intact sedentary group (P<0.05). Our results suggest that the resistance training proposed in our work was efficient in reverting the deleterious effects of ovariectomy on bone tissue, and also produced modeling effects in intact rats. On the other hand, ovariectomy reduced the activity of MMP-2 and produced deleterious effects on bone tissue, mimicking menopause intrinsically.

Resistance training associated with the administration of anabolic-androgenic steroids improves insulin sensitivity in ovariectomized rats

The aim of the present study was to investigate the effects of anabolic-androgenic steroids and resistance training (RT) on insulin sensitivity in ovariectomized rats. Adult female Wistar rats were divided into ten experimental groups (n = 5 animals per group): (1) sedentary (Sed-Intact); (2) sedentary ovariectomized (Sed-Ovx); (3) sedentary nandrolone (Sed-Intact-ND); (4) sedentary ovariectomized plus nandrolone (Sed-Ovx-ND); (5) trained (TR-Intact); (6) trained nandrolone (TR-Intact-ND); (7) trained ovariectomized (TR-Ovx); (8) trained ovariectomized plus nandrolone; (9) trained sham; and (10) trained ovariectomized plus sham. Four sessions of RT were used, during which the animals climbed a 1.1 m vertical ladder with weights attached to their tails. The sessions were performed once every 3 days, with between four and nine climbs and with eight to twelve dynamic movements per climb. To test the sensitivity of insulin in the pancreas, glucose and insulin tolerance tests were performed. For insulin sensitivity, there was a statistically significant interaction for the TR-Ovx group, which presented higher sensitivity than the Sed-Intact, Sed-Ovx, and TR-Intact groups. Sed-Intact-ND and TR-Intact-ND groups exhibited higher values of insulin sensitivity than the Sed-Intact group. Except for the TR-Intact group, sensitivity was greater in trained groups than in the Sed-Intact group. There was higher insulin sensitivity in the TR-Intact-ND group than in the Sed-Intact and Sed-Intact-ND groups (P < 0.05). In conclusion, ovariectomy and short-term RT alone induced no change on insulin action. Administration of nandrolone decanoate improved insulin action, mainly when it was associated with RT.

Effects of ovariectomy and resistance training on MMP-2 activity in rat calcaneal tendon

Tendon remodeling relies on extracellular matrix (ECM) restructuring by the matrix metallopeptidases (MMPs). The aim of this study was to investigate MMP-2 activity in different regions of the calcaneal tendon (CT) after resistance training (RT) in ovariectomized rats. Wistar adult female rats were grouped into sedentary (Sed-Intact), ovariectomized sedentary (Sed-Ovx), acute exercise (AcuteEx-Intact), ovariectomized acute exercise (AcuteEx-Ovx), resistance trained (ChronicEx-Intact), and ovariectomized resistance trained (ChronicEx-Ovx) (n = 10 each group). The RT protocol required the animals to climb a 1.1-m vertical ladder with weights attached to their tail. The sessions were performed once every 3 days with 4-9 climbs and 8-12 dynamic movements per scaling. The acute groups performed one session and the chronic groups underwent 12 weeks of RT. There was an increase in total MMP-2 activity in Sed-Ovx, AcuteEx-Intact, and ChronicEx-Intact compared with that in Sed-Intact in the proximal region of CT. AcuteEx-Ovx exhibited higher total MMP-2 than Sed-Ovx and AcuteEx-Intact in the distal region of CT. Chronic-Ovx presented lower total MMP-2 activity than Sed-Ovx and Chronic-Intact in the distal region of tendon. The active MMP-2 was higher for the AcuteEx-Ovx than Sed-Ovx and AcuteEx-Intact in proximal region of tendon. There was higher active MMP-2 in the distal region of tendon in the Acute-Ovx than in the Sed-Ovx and AcuteEx-Intact. Ovariectomy and resistance exercise modulate MMP-2 activity according to specific tendon region, indicating a differentiated tissue remodeling.

Effects of ovariectomy and resistance training on lipid content in skeletal muscle, liver, and heart; fat depots; and lipid profile

The aim of the present study was to investigate the effects of resistance training on skeletal muscle lipid content, liver lipid content, heart lipid content, fat depots, and lipid profile in ovariectomized rats. Wistar adult female rats were divided into 4 groups (n = 10 per group): sedentary (Sed-Intact), sedentary ovariectomized (Sed-Ovx), strength trained (ChronicEx-intact), and strength trained ovariectomized (ChronicEx-Ovx). A 12-week strength-training period was used, during which the animals climbed a 1.1-m vertical ladder with weights attached to their tails. The sessions were performed once every 3 days, with 4-9 climbs and 8-12 dynamic movements per climb. Ovariectomy increased liver lipid content and fat depots, and heart and muscle lipid content. There was an increase in the atherogenic index and a negative change in lipid profile because of the ovariectomy. Resistance training decreased lipid content in the liver, soleus, and tibialis anterior, decreased fat depots (mesenteric and retroperitoneal), and changed the lipid profile, independently of ovarian hormone status. These results indicate the potential benefits of resistance training as an alternative strategy to control the effects of ovariectomy on fat depot, lipid profile, and tissue lipid content.

Effects of ovariectomy and resistance training on MMP-2 activity in skeletal muscle

Matrix metallopeptidases (MMPs) are crucial to the maintenance of healthy tissue. The aim of this study was to investigate MMP-2 activity in gastrocnemius, soleus, tibialis anterior (TA), and extensor digitorium longus (EDL) muscle after resistance training in ovariectomized rats. Wistar adult female rats were grouped into 7 groups (n = 10 per group): sedentary (Sed-Intact); ovariectomized sedentary (Sed-Ovx); pseudo-ovariectomized sedentary (Sed-Pseudo); acute exercise (AcuteEx-Intact); ovariectomized acute exercise (AcuteEx-Ovx); strength trained (ChronicEx-Intact); and ovariectomized strength trained (ChronicEx-Ovx). A 12-week resistance training period, during which the animals climbed a 1.1-m vertical ladder with weights secured to their tails, was used. The sessions were performed once every 3 days, with 4-9 climbs and 8-12 dynamic movements per climb. The MMP-2 activity was analyzed by zymography. There was higher MMP-2 activity in soleus muscle in the ChronicEx-Intact and ChronicEx-Ovx groups, and lower MMP-2 activity in the AcuteEx-Ovx group, compared with the Sed-Intact group (p < or =0.05). The Sed-Ovx and ChronicEx-Ovx groups presented lower MMP-2 activity than the Sed-Intact group in TA. There was higher MMP-2 activity in AcuteEx-Intact and the AcuteEx-Ovx compared with the Sed-Intact and Sed-Ovx in TA, respectively (p < or = 0.05). In TA and EDL, training increased MMP-2 activity in the Sed-Intact group. No statistically significant alterations were observed for gastrocnemius muscle. Strength training increases MMP-2 activity in soleus, TA, and EDL muscle, which may be important for muscle remodeling. Ovariectomy downregulates MMP-2 in TA and EDL, which may compromise muscle function.

MMP-2, jumping exercise and nandrolone in skeletal muscle

Matrix metalloproteinases (MMPs) are crucial to the development and maintenance of healthy tissue. The aim of this study was to investigate MMP-2 activity in gastrocnemius, soleus, extensor digitorium longus (EDL) and tibialis anterior (TA) muscles after exercise associated with an anabolic androgenic steroid (AAS). Wistar rats were grouped into: sedentary (S); sedentary with AAS (AAS); trained without (T) and with (AAST) AAS. Exercised groups performed a 7-week water-jumping program. The exercise increased MMP-2 activity in gastrocnemius and soleus, but not in TA and EDL. The AAS treatment decreased MMP-2 activity of EDL, as compared to the S group, with no effect in gastrocnemius and soleus. The association of AAS and training restored the normal MMP activity of EDL. Training increases tissue turnover in primary motor muscles, which in turn respond differently to AAS treatment. This data may be useful for a better understanding of muscular physiology under AAS use.