José A. de Paz

Changes in oxidative stress markers and NF-κB activation induced by sprint exercise

This study was aimed to investigate changes in blood markers of oxidative damage induced by short-term supramaximal anaerobic exercise and to determine whether oxidative stress was associated to activation of the redox-sensitive transcription factor nuclear factor-κB (NF-κB). Both a single Wingate test (WAnT) test and series of four WAnTs separated by 60 min rest intervals were carried out by eight professional cyclists. Leukocyte 8-OH-2-deoxyguanosine levels were significantly elevated 24 h after both exercise protocols. A significant decrease in blood reduced glutathione (GSH) concentration was observed immediately after and at 15, 60 and 120 min of the single WAnT, followed by a return to basal value after 24 h. This decrease was parallel to a significant increase of the oxidised/reduced glutathione (GSSG/GSH) ratio, to an activation of NF-κB and to a significant decrease in the protein level of its inhibitor IκB. GSH concentration and the GSSG/GSH ratio changed significantly for the first three of the WAnTs series and normalised thereafter. A significant activation of NF-κB and a decrease in the IκB protein level were also detected. We conclude that short-term supramaximal anaerobic exercise induces oxidative stress, as evidenced by non cumulative damage to macromolecules and changes in the glutathione status. Our data also indicate that high intensity anaerobic work gives rise to an activation of the transcription factor NF-κB accompanied by a degradation of IκB.

Eccentric training impairs NF-κB activation and over-expression of inflammation-related genes induced by acute eccentric exercise in the elderly

The present study was aimed to investigate in elderly humans changes in NF-kappaB activation and in the expression of the inflammation-related genes inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) and interleukin-6 (IL-6) induced in peripheral blood mononuclear cells (PBMC) by acute eccentric exercise and by submaximal eccentric training. Eleven subjects, aged 66-75 years, carried out 2 bouts of eccentric exercise separated by 8 weeks of training. Following the first bout, NF-kappaB activation, and protein level of p50/p65 subunits, phospho-IkappaBalpha and phospho-IKKalpha increased, while IkappaBalpha protein level was significantly reduced. This was accompanied by a significant increase in iNOS, COX-2 and IL-6 mRNA protein level and protein content. Changes were significantly attenuated following the second exercise bout. In conclusion, acute eccentric exercise increases NF-kappaB activation and the expression of several inflammation-related genes in PBMC from elderly individuals. Regular eccentric training might be an effective method of preventing undesirable inflammatory responses induced by eccentric exercise.

The Effects of Movement Velocity During Squatting on Energy Expenditure and Substrate Utilization in Whole-Body Vibration

The purpose of this study was to examine whether and how cycle time duration affects energy expenditure and substrate utilization during whole-body vibration (WBV). Nine men performed 3 squatting exercises in execution frequency cycles of 6, 4, and 2 seconds to 90° knee flexion with vibration (Vb-) (frequency was set at 30 Hz and the amplitude of vibration was 4 mm) and without vibration (Vb-) during 3 minutes, each with an additional load of 30% of the subjects body weight. A 2-way analysis of variance for &OV0312;O2 revealed a significant vibration condition main effect (p < 0.001) and a cycle time duration effect (p < 0.001). When differences were analyzed by Fishers LSD test, cycle time duration of 2 seconds was significantly different from 4 and 6 seconds, both in Vb+ and Vb-. Total energy expenditure (EEtot), carbohydrate oxidation rate (EEcho), and fat oxidation rate (EEfat) demonstrated a significant vibration condition main effect (EEtot: p < 0.01; EEcho: p < 0.001; EEfat: p < 0.001) and cycle time duration main effect (EEtot and EEcho: p < 0.001; EEfat: p < 0.01). EEtot,EEcho, and EEfat post hoc comparisons indicated that values for the 2-second test significantly differed from 4 and 6 seconds when compared in the same vibration condition. &OV0312;O2 and EE values were greater in Vb+ than in Vb-conditions with the same cycle time duration. Our study confirms that squatting at a greater frequency helps to maximize energy expenditure during exercise with or without vibration. Therefore, cycle time duration must be controlled when vibration exercise is prescribed.

Effects of an exercise programme on self-esteem, self-concept and quality of life in women with fibromyalgia: a randomized controlled trial

This study was aimed to investigate the effects of an exercise trial on self-esteem, self-concept and quality of life in patients with fibromyalgia and to evaluate whether improvements in psychological distress were related to changes in physical functioning. Twenty-eight women with a primary diagnosis of fibromyalgia were randomized to a usual care control group or to a 12-week supervised training programme consisting of 3 weekly sessions of aerobic, strengthening and flexibility exercises. Outcomes were physical functioning (Fibromyalgia Impact Questionnaire (FIQ), lower-body strength and flexibility) and psychological functioning (SF-36, Rosenberg self-esteem scale and Erdmann self-concept scale). Outcomes were measured at study entry and at the end of the intervention. Compared to the control group, statistically significant improvements in self-esteem, self-concept, FIQ, physical functioning, role physical, bodily pain, vitality, role emotional, social functioning, mental health, isometric strength, muscular endurance and flexibility were evident in the exercise group at the end of treatment. Self-esteem and self-concept scores were correlated positively with role emotional, mental health and the mental component summary of SF-36 and were negatively correlated to FIQ scores. No significant correlation existed between self-esteem or self-concept and isometric strength, muscular endurance or flexibility. Our results highlight the need for a broader array of physical and mental outcomes and the importance of examining patient’s perceptions in future research therapies.

Role of Toll-like receptor 2 and 4 signaling pathways on the inflammatory response to resistance training in elderly subjects

This study assessed the effects of a resistance exercise training program on the inflammatory response associated with Toll-like receptor (TLR) 2 and TLR4 signaling pathways in senior participants. Twenty-six healthy subjects (age, 69.5 ± 1.3) were randomized to a training (TG; n = 16) or a control (CG; n = 10) group. TG performed an 8-week resistance training program, while CG followed their daily routines. Peripheral blood mononuclear cells were isolated from blood samples obtained before and after the intervention, and levels of proteins involved in the TLR2, TLR4, and myeloid differentiation primary response gene 88 (MyD88)-dependent and MyD88-independent pathways were analyzed. The inflammatory status was evaluated through messenger RNA (mRNA) and protein content of interleukin (IL)-10 and tumor necrosis factor alpha (TNF-α) and plasma levels of C-reactive protein (CRP). After the 8-week resistance training, TLR2 and TLR4 protein expression was reduced in TG. MyD88, p65, phospho-p38, TIR domain-containing adaptor inducing interferon (TRIF), IKKi/IKKε, phospho-interferon regulatory factor (IRF) 3, and phosho-IRF7 were also downregulated in TG after the intervention. The training program induced an increase of phospho-extracellular signal-regulated kinases 1 and 2 (ERK1/2) and Hsp70 and a reduction of Hsp60. While TNF-α mRNA and protein values remained unchanged in both TG and CG, IL-10 mRNA and protein content were upregulated in TG after the intervention. CRP values decreased in TG only. The increase in Hsp70 negatively correlated with TLR2 and TLR4 downregulation. These data suggest that resistance exercise may represent an effective tool to ameliorate the pro-inflammatory status of old participants through an attenuation of MyD88-dependent and MyD88-independent TLR2 and TLR4 signaling pathways.

Monitoring biological and psychological measures throughout an entire season in male handball players

Abstract The aim of this study was to monitor biological markers of inflammation and oxidative stress, mood states, and recovery-stress states throughout an entire season in male handball players. Fourteen handball players (age 20.1±2.5 years) with a regular training and competitive background in handball (11.0±3.7 years) from the same club volunteered to participate. All participants completed 40 weeks of training. The training load was increased progressively throughout the season. Blood samples were collected and questionnaires were administered during preparatory, competitive, and recovery periods. Blood C-reactive protein and oxidized glutathione (GSSG) concentrations increased during periods of high load, while the reduced/oxidized glutathione ratio (GSH/GSSG) decreased. These changes were accompanied by a significant increase in total leukocyte count. Positive correlations were found between C-reactive protein, GSSG, GSH/GSSG ratio, and training load. No changes were observed in the Total Mood Disturbance score of the Profile of Mood States (POMS). However, scores on some Recovery-Stress Questionnaire for Athletes subscales, such as Injury, Physical Recovery, and Being in Shape, correlated with training load. Findings indicate that during periods of high training load, handball players developed a low grade of inflammation and oxidative state. Results support the usefulness of monitoring psychological and biological markers of inflammation, oxidative stress, and training load during season.

Effects of eccentric exercise on toll-like receptor 4 signaling pathway in peripheral blood mononuclear cells.

This study aimed to investigate the response of the toll-like receptor 4 (TLR4) signaling pathway to an acute bout of eccentric exercise, and to assess whether eccentric training attenuated the effects induced by acute eccentric exercise. Twenty men (22.4 ± 0.5 yr) were divided into a control group (CG, n = 8) and a training group (TG, n = 12). Both groups performed two acute eccentric bouts on a squat machine in a 9-wk interval. During this time, TG followed a 6-wk eccentric training program (3 session/wk; 3-5 sets of 10 repetitions with loads ranging between the 40 and 50% of maximal isometric voluntary contraction). CD14, TLR4, and TNF-α mRNA levels, and CD14, TLR4, myeloid differentiation factor 88, tumor necrosis factor receptor-associated factor 6, TIR-domain-containing adapter-inducing interferon-β, phospho-IκB kinases, phospho-IκB, phospho-ERK-1/2, and TNF-α protein concentration were measured in peripheral blood mononuclear cells, before, immediately, and 2 h after each eccentric bout. The first acute eccentric bout triggered a proinflammatory response mediated by an upregulation of all of the factors measured within the TLR4 signaling pathway. Following the training period and after the second acute bout, CG showed a similar proinflammatory response than that seen after the first bout. However, the eccentric training intervention decreased significantly the protein concentration of all factors analyzed in TG compared with results obtained after the first bout. These results suggest that the TLR4-signaling pathway plays a critical role in the proinflammatory response seen after acute eccentric exercise. This response was attenuated after an eccentric training program through myeloid differentiation factor 88-dependent and -independent pathways.

Effects of short vs. long rest period between sets on elbow-flexor muscular endurance during resistance training to failure.

This study aimed to examine short- term resistance training effects of resting period length between sets on maximal number of repetitions and mean velocity over a moderate-intensity (60% of the maximum voluntary isometric contraction [MVIC]) set to failure on elbow-flexor muscles. The MVIC and surface electromyographic activity (sEMG) were also measured. Twenty-one untrained subjects were divided into 3 groups: short rest between sets (1 minute; SR), long rest between sets (4 minutes; LR), and nontraining control group (CG). The SR and LR performed 3 sets to failure in an arm-curl machine, 2 days per week for 5 weeks, with moderate loads (60–75% of the MVIC). The LR completed a significantly higher (31.6%, p < 0.05) total training volume than the SR. Both training groups enhanced the maximal number of repetitions to failure, with no significant differences in the magnitude of gains. The posttraining average velocity achieved by the SR at 40, 50, 60, 70, 80, and 90% of the total number of repetitions completed was significantly higher (p < 0.05) than the corresponding average velocity achieved on pretraining conditions, whereas no significant differences were observed in the LR. No significant changes in the MVIC or sEMG were observed in any group. We conclude that short-term elbow-flexor resistance training to failure, allowing 1 or 4 minutes of rest between sets, induces similar gains concerning local muscular endurance. Nevertheless, only the SR training approach reduced the rate of decline in the average repetition velocity during a set to failure. This can be of some importance in sport modalities in which not only the maximal number of repetitions (e.g., muscle endurance), but also a greater maintenance of high repetition velocities, may be critical for performance.

Functional, balance and health determinants of falls in a free living community Amazon riparian elderly

The aim of this study was to investigate socio-economic, clinical, anthropometric, balance and functional fitness factors present in Amazon riparian older persons that can be associated with a risk of falling. A cross sectional study was performed with 637 riverine elderly residents (≥60 years old) in Maués city Amazonas, Brazil. The elderly were grouped in two categories with and without a history of falls in the past six months. The following variables were compared between these groups: self-reported social and health conditions; biochemical and physiological variables related to the control of metabolic diseases; body composition; hand grip strength; functional fitness evaluation using the Senior Fitness Test (SFT) battery, and balance condition using the Berg Balance Test (BBT). The prevalence of at least one fall in the past six months was 24.6% (n=157) and was similar between the sexes. The mean age between males and females with and without a history of falls was also similar (males with falls=72.67 ± 8.86; males with no falls=73.26 ± 7.58) female falls=71.78 ± 8.18, female with no falls=71.48 ± 8.17). A history of falls was associated with hospitalization in the last year and to self-health perception to both sexes and presence of chronic morbidity and percentage of body fat (BF) to women. However, the other variables including balance and functional fitness, did not present differences between elderly with and without a history of falls. These results suggest that falls experienced by the riparian elderly are strongly associated to accidents due to environmental conditions related to daily life.

Comparison of technical and physiological characteristics of prepubescent soccer players of different ages

Fernandez-Gonzalo, R, De Souza-Teixeira, F, Bresciani, G, García-López, D, Hernández-Murúa, JA, Jiménez-Jiménez, R, and De Paz, JA. Comparison of technical and physiological characteristics of prepubescent soccer players of different ages. J Strength Cond Res 24(7): 1790-1798, 2010-Although soccer is one of the most widely played sports around the world, studies about young players and the success factors in soccer are still scarce. Therefore, the purpose of this study was to offer some insight into the factors contributing to success in this sport and to describe how physiological and technical performance evolves in young soccer players. Soccer technical skills during match play, maximum voluntary isometric contraction and power of lower limbs, jumping ability and endurance parameters were assessed in 30 prepubescent male soccer players with the same experience in soccer training. Subjects were divided into 2 groups of 15 children, a younger group (YG), aged 9.4 ± 0.3 years, and an older group (OG), aged 11.8 ± 0.2 years. Correlations between technical and physiological parameters were also described. Significant difference was set at p < 0.05. Differences between YG and OG appeared in physiological performance, mainly in &OV0312;o2peak expressed in absolute values, &OV0312;o2 at different speeds, perceived exertion in treadmill test, jump performance, strength, and peak power of lower limbs. Among the technical skills measured, significant differences were found only in heading. The differences found between groups showed that most physical capacities that were measured here have an important increase during the first stages of puberty, pointing out that a specific training at these ages is necessary to get an appropriate basis for future performance. Besides, over 30% of the technical performance measured in this study can be explained with the physiological parameters. The data shown in this paper help to determine the most important capacities in youth soccer, which can facilitate the development of more appropriate selection models and trainings.