Research Center in Physical Activity

Porto, Portugal

Research Center in Physical Activity

Porto, Portugal
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Alves A.J.,Research Center in Physical Activity
Metabolism: Clinical and Experimental | Year: 2010

Hypoxia-inducible factor 1 (HIF-1) is a transcription factor that regulates gene expression in response to hypoxia and has been associated with athletic performance. The aims of this study were (1) to determine the frequency distribution of HIF1A Pro582Ser (rs11549465) polymorphism among 155 Israeli athletes (sprinters and endurance athletes) and 240 healthy controls and (2) to analyze the influence of the interaction between HIF1A Pro582Ser and ACTN3 R577X (rs1815739) genotypes on sprint performance. There were no differences across the HIF1A genotype and allele frequencies among endurance athletes, sprinters, and controls. Similarly, no differences were found between the subgroups of top-level and national-level endurance athletes, or between top-level and national-level sprinters. Conversely, interaction effects were found between HIF1A Pro582Ser and ACTN3 R577X polymorphisms and sprinters. The proportion of HIF1A Pro/Pro + ACTN3 R/R genotypes was significantly higher in sprinters than in endurance athletes and healthy controls (P = .002). In addition, the odds ratio for HIF1A Pro/Pro + ACTN3 R/R genotype carriers being a sprinter was 2.25 (95% confidence interval, 1.24-4.1); and that for HIF1A Pro/Pro + ACTN3 R/R genotype carriers being an endurance athlete was 0.5 (95% confidence interval, 0.2-1.24). We conclude that HIF1A Pro582Ser polymorphism by itself is not critical in determining sprint performance. However, sprinter performance is determined by the interaction between the wild-type HIF1A Pro/Pro genotype and ACTN3 RR genotype. © 2010 Elsevier Inc. All rights reserved.

Silva J.R.,University of Porto | Ascensao A.,University of Porto | Ascensao A.,Research Center in Physical Activity | Marques F.,University of Porto | And 4 more authors.
European Journal of Applied Physiology | Year: 2013

The main aim was to analyse the impact of an official match on hormonal and redox status, muscle damage and inflammation and neuromuscular function. Seven high-level male soccer players from the same team performed an official match and data were collected 72 h before, 24, 48 and 72 h post-match. Plasma testosterone/cortisol ratio (T/C), creatine kinase (CK), superoxide dismutase (SOD), glutathione peroxidase (GPX) and reductase (GR) activities, myoglobin (Mb), C-reactive protein (CRP), uric acid (UA), protein sulfhydryls (-SH), malondialdehyde (MDA) concentrations and total antioxidant status (TAS) were measured. Sprint, jump and change of direction performance, and maximal isokinetic knee extension and flexion were obtained as neuromuscular functional parameters. Cortisol increased and T/C decreased until 48 h recovery (P < 0.05). Mb, CRP and -SH (P < 0.05) increased at 24 h and CK, TAS, SOD and MDA (P < 0.05) increased up to 48 h recovery. GR increased and GPX decreased at 24 h recovery (P < 0.05). Jump performance decreased 24 h post-match (P < 0.05), but no significant alterations in sprint, change of direction and muscle strength were observed. In conclusion, an official match resulted in changes in plasma biomarkers until 48 h of recovery period, without major impact on performance. © 2013 Springer-Verlag Berlin Heidelberg.

Silva J.R.,University of Porto | Magalhaes J.F.,University of Porto | Magalhaes J.F.,Research Center in Physical Activity | Ascensao A.A.,University of Porto | And 4 more authors.
Journal of Strength and Conditioning Research | Year: 2011

The purpose of this study was to analyze the effects of an entire season on physical fitness parameters (PFPs) in male professional soccer players (N = 18). Performance in 5- and 30-m sprint (T5 and T30), countermovement jump (CMJ), agility (T-test), knee extensor (KE) and knee flexor (KF) isokinetic strength, hamstrings/quadriceps strength ratio (H/Q) and bilateral differences (BDs), and Yo-Yo intermittent endurance test 2 (YYIE2) was evaluated in 4 moments (E1-E4) throughout the season. Individual match playing time was quantified. Significant improvements in CMJ and YYIE2 from E1 to E2 were observed (p < 0.05-0.01). The T30 improved from E2 to E3 (p < 0.01). The CMJ decreased from E2 to E3 and E4, and YYIE2 fromE2 to E4 (p < 0.05). There were increments in the H/Qratio and Agility from E1 and E2 to E3 and E4 (p< 0.05-0.01). Significant correlations were found in all evaluation points between different PFPs and between changes in strength parameters and agility, T5 and T30, CMJ, and YYIE2 (p < 0.05-0.001). Influence of individual match playing time was correlated to changes in T5 (E1 to E3; r = 20.705), KE nondominant leg (KEND; E2 to E3; r = 0.786), and KF (E3 to E4; r = 0.575-0.590). The interrelationship between muscle strength (e.g., KE), sprint (e.g., T5), and jump abilities (CMJ) suggests the importance ofmuscle strength and power training for soccer. This study suggests that the systematic participation of the players in soccer matches favors the increase and maintenance of soccer players KE and KF muscle strength and sprint ability (T5). Thus, given the unique demands of actual match play, coaches should try to incorporate a competitive friendly match in the weekly training cycle of nonstarter players. © 2011 National Strength and Conditioning Association.

Silva J.R.,University of Porto | Magalhaes J.,University of Porto | Magalhaes J.,Research Center in Physical Activity | AscensaO A.,University of Porto | And 4 more authors.
Journal of Strength and Conditioning Research | Year: 2013

Silva, JR, Magalhaes, J, Ascensao, A, Seabra, AF, and Rebelo, AN. Training status and match activity of professional soccer players throughout a season. J Strength Cond Res 27(1): 20-30, 2013-The purpose of this study was to examine match activity (MA) and fatigue development (FD) during official soccer games in different moments of a season and the influence of training status (TS) on MA and FD. Match activity of 13 professional players was examined by time-motion analysis at 4 time points of a competitive season. In addition, per time point within the 2-week period between the 2 games videofilmed, players performed the following physical tests: countermovement jump, 5- and 30-m sprints, change of direction, knee extensor and flexor isokinetic strength, and Yo-Yo intermittent endurance test-level 2. The players covered a greater high-intensity distance running (HI; p , 0.05) in the last quarter of the season (E4) than in the second (E2) and the third (E3) quarters. Within each assessment period, a greater distance was covered in HI during the peak 5-minute period of the match (P5-min) than in the 5-minute period after P5-min (Next5-min) and the remaining 5-minute periods (Av5-min; p , 0.05) of the match. Also, P5-min was higher in E4 than in the beginning of the season (E1, E2, and E3; p , 0.05). The physical fitness variables, composites scores of power-related and isokinetic strength tests were correlated (r ranging between 0.59 and 0.73, p , 0.05) with game physical parameters (GPPs) analyzed by time motion. Soccer players were found to cover more HI during the game and in the P5-min toward end of season. The players with greater muscle strength and power expressed lower performance decrements in theGPPs. In conclusion, the results highlight the relevance of players' neuromuscular function on game physical performance. © 2013 National Strength and Conditioning Association.

Silva J.R.,Aspetar Qatar Orthopaedic and Sports Medicine Hospital | Marques F.,University of Porto | Pereira L.,University of Porto | Seabra A.,Research Center in Physical Activity | And 2 more authors.
Applied Physiology, Nutrition and Metabolism | Year: 2014

This study aimed to analyze changes in performance, muscle function, and stress-related biochemical markers in professional soccer players (n = 14) at 4 timepoints (3 for performance and 4 for stress-related biochemical markers) during the soccer seasonOpreseason (E1), midseason (E2), end of the season (E3)Oand after the end of the recovery period (E4). Performance in 5- and 30-m sprints, countermovement jump, and agility, and maximal isokinetic knee extension and knee flexion strength were measured (E1 to E3). We observed increased in-season levels of myoglobin (E2 > E1 and E4; p < 0.05), a higher testosterone/cortisol ratio (T/C), and increased levels of creatine kinase (CK), C-reactive protein, superoxide dismutase (SOD), protein sulfhydryls (-SH), and malondialdehyde (E2 and E3 > E1 and E4; p < 0.05). Lower cortisol concentrations (E3 < E1 and E4; p < 0.05) and glutathione reductase activity (E3 < E2 and E4; p < 0.05) were observed at the end of the season. T/C, CK, SOD, -SH, and malondialdehyde decreased during the off-season, and cortisol and glutathione reductase increased (E3 < E4; p < 0.05). Agility increased in E2 and E3 (p < 0.01). Significant correlations were found during the season between hormonal and muscle function parameters (r = 0.56-0.86; p < 0.05). In addition, in E2, significant associations were observed between match-accumulated time (MATE2; minutes played by each player during the competition period), performance, and hormonal and redox parameters (r = 0.456-0.615; p<0.05). In conclusion, this study shows that soccer players face significant changes in biomarkers of physiologic strain (muscle damage and oxidative stress-related markers) during the season, but values return to normal during the off-season. Additionally, MAT influences physical, hormonal, and oxidative stress-related parameters in professional soccer players.

Mota N.,Polytechnic Health Institute of the North | Ribeiro F.,Polytechnic Health Institute of the North | Ribeiro F.,Research Center in Physical Activity
Isokinetics and Exercise Science | Year: 2012

This study aimed to investigate the association between shoulder proprioception and shoulder rotators strength in water polo players. Twenty male water polo players aged 20.2 ± 2.3y participated in the study. Shoulder proprioception was evaluated by assessing joint position sense (JPS) at 30° of external rotation and at 30° of internal rotation. Shoulder external and internal rotators concentric and eccentric muscle strength was evaluated isokinetically at 120°/s. JPS acuity at 30° of external rotation [4.7 (3.5°)] was similar to that observed at 30° of internal rotation [4.0 (5.3°)]. The external/internal rotators strength ratio were 0.67 (0.23) and 0.66 (0.18), respectively for concentric and eccentric efforts while the dynamic control ratio was 0.69 [0.16]. Negative and significant correlations were found between relative error at 30° of external rotation and concentric and eccentric external rotators PT: r = -0.445 and r = -0.483, respectively, and the eccentric strength ratio of the external to internal rotators (r =-0.505). In addition the dynamic control ratio was lower than the recommended values for overhead athletes, which may expose/predispose the players to shoulder injury. © 2012 - IOS Press and the authors. All rights reserved.

Guilherme J.,University of Porto | Garganta J.,University of Porto | Graca A.,University of Porto | Seabra A.,University of Porto | Seabra A.,Research Center in Physical Activity
Revista Brasileira de Cineantropometria e Desempenho Humano | Year: 2015

The functional asymmetry of the lower limbs has been considered an important factor in the performance of soccer players. In this sense, the purpose of this study was to examine the effects of specific technical training for non-preferred foot on its utilization rate during the game; and to investigate if interruption of a technical training program me for the non-preferred foot influences its utilization rate during the game. Fifty young soccer players were randomly divided into two groups: G1 (n=26, 9.50±1.04 years) and G2 (n=24, 9.58±1.02 years). At the beginning of the first 4 months, each player’s use of both feet during the game was assessed. Te study lasted eight months divided into two periods of four months. In the first training period G1 was subjected to a technical training programme directed to the non-preferred foot, while G2 had no constraints on the use of both feet. At the end of the 4th month the two groups were newly assessed. During the second training period G1 and G2 reversed the training programmes. After the 8 months of training the evaluation of the utilization rate of both feet during small-side games was again performed. Te main conclusions of the study were: (i) the technical training of the non-preferred foot allowed significant increases in its utilization rate during small-sided games; (ii) the interruption of such training partially reversed this effect. Thus, technical training for the non-preferred foot should be systematically performed in order to maintain the positive effects induced over functional asymmetry. © 2015, Universidade Federal de Santa Catarina. All rights reserved.

Ribeiro F.,Research Center in Physical Activity | Alves A.J.,Research Center in Physical Activity | Duarte J.A.,Research Center in Physical Activity | Oliveira J.,Research Center in Physical Activity
International Journal of Cardiology | Year: 2010

There is an increasing evidence that endothelial dysfunction and vascular wall inflammation are present in all stages of atherosclerosis. Atherosclerosis does not have to necessarily progress to an acute clinical event. Several therapeutic strategies exist, such as exercise training, which mitigates endothelial dysfunction and inflammation. Exercise training consistently improves the nitric oxide bioavailability, and the number of endothelial progenitor cells, and also diminishes the level of inflammatory markers, namely pro-inflammatory cytokines and C-reactive protein. However, the mechanisms by which exercise improves endothelial function in coronary artery disease patients are not fully clarified. Several mechanisms have been proposed to explain the positive effect of exercise on the disease progression. They include the decrease in cytokine production by the adipose tissue, skeletal muscles, endothelial cells, and blood mononuclear cells, and also, the increase in the bioavailability of nitric oxide, antioxidant defences, and regenerative capacity of endothelium. This study aims to provide a critical review of the literature linking exercise, inflammation, and endothelial dysfunction in coronary artery patients, and to discuss the potential mechanisms behind the exercise-training improvement of endothelial function and inflammatory status. © 2009 Elsevier Ireland Ltd. All rights reserved.

PubMed | Research Center in Physical Activity
Type: Journal Article | Journal: The Journal of sports medicine and physical fitness | Year: 2011

The aim of the present study was to analyze the physiological and neuromuscular impact of a one 3-set beach-volleyball match and to analyze the ability of the players to recover from fatigue.Heart rate (HR) and blood lactate concentration (BLC) were measured in sixteen Portuguese male elite volleyball players during beach-volleyball matches. Vertical countermovement jump (CMJ), sprint (7.5 and 15m) ability and maximal isometric voluntary contraction (MIVC) were evaluated at baseline, immediately (0h) and 3 hours after each match.Mean HR during the match was 146 3 bpm (117 2-185 3 bpm) corresponding to about 75% of HRmax (61-90%HRmax). Players spent 34% of match time above 80% HRmax. BLC during the 3-sets increased from rest (0.95 0.23 vs. 2.10 0.66 [1st-set] vs. 2.41 0.15 [2nd-set] vs. 2.39 0.21mM [3rd-set]). No changes in CMJ were observed at 0 and 3h. Knee extensor and flexor muscles MIVC decreased at 0h (~19 and 17%, respectively) and returned to baseline 3h after. Sprint performance was the only variable that was impaired both at 0h and 3h after the match (~3%).Beach-volleyball is performed intermittently at moderate-to-high intensity with brief bouts of high intensity exercise interspersed by long low intensity periods. Match induced a temporary reduction in lower limb strength and sprinting time but 3h after the match all variables with the exception of the sprinting time, that was only slightly reduced, were recovered.

PubMed | Research Center in Physical Activity
Type: Journal Article | Journal: Annals of human biology | Year: 2013

There is clear evidence that environmental factors play an important role regarding physical activity (PA) and sedentary behaviour (SB) in youth. This short report highlights seasonal differences in the amount and intensities of PA and SB, in Portuguese youth.Three hundred and eighty-seven participants (aged 14.71.9 years), 220 girls, used the Actigraph GT1M accelerometer for 7 days (15-second epochs), between January and June in 2008. PA and SB differences were assessed using an ANCOVA.Boys had significantly higher values of PA, with the exception of Light intensity. Girls were significantly more sedentary. PA intensities and SB changed significantly according to gender and month of assessment. SB (Gender F=16.32, p<0.001; Month F=2.95, p<0.013), Light PA (Gender F=9.30, p=0.002; Month F=8.37, p<0.001; Gender*Month F=2.24, p=0.050), Moderate PA (Gender F=40.04, p<0.001), Vigorous PA (Gender F=32.89, p<0.001; Month F=2.56, p=0.027). Both genders increased PA from winter to summer months and SB decreased.Seasonality in PA intensities and SB suggest that interventions to promote PA and decrease SB must be tailored to take into consideration the month of the year they are going to be implemented and also gender characteristics.

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