135 research outputs found
Can Off-Training Physical Behaviors Influence Recovery in Athletes? A Scoping Review
Recently, the attention on recovery in sport increased enormously although there is lack of scientific evidence on the role of lifestyle in terms of movement [i.e., physical behaviors (PBs)], apart from sleep. Few studies assessed physical activity (PA) and sedentary behavior (SB) in athletes. The aims of this scoping review were to answer to the following scientific questions: (1) How active/inactive are competitive athletes out of training? (2) Do off-training PBs affect recovery, performance, and health? (3) What strategies can be implemented to improve recovery using off-training PBs, apart from sleep? From 1,116 potentially relevant articles, nine were eligible for inclusion in this review. The main issues identified were related to the heterogeneity concerning the types of sports, age category, gender, competitive level, sample size, and instruments/devices adopted, the paucity of studies investigating the effects of PBs while awake on recovery, and the lack of experimental designs manipulating PBs while awake to accelerate recovery. Furthermore, PA and SB domains were rarely investigated, while no research articles focused on the combined effect of 24-h PBs. Eight out of nine studies measured PA, seven SB, and two included sleep. Three studies included training practice into PA measurement by the means of accelerometry. Overall, almost the totality of the athletes achieved recommended PA levels although they sustained prolonged SB. In conclusion, more descriptive researches are needed in different athletic populations and settings. Furthermore, experimental designs aimed at investigating the effects of PBs manipulation on recovery and the putative mechanisms are encouraged
The psychobiological model: a new explanation to intensity regulation and (in)tolerance in endurance exercise
Os mecanismos que explicam fadiga e exaustão, controle da intensidade e (in)tolerância ao exercício de resistência cardiorrespiratória têm sido estudados há mais de um século. Apesar de diversas teorias científicas atualmente disponíveis, nos últimos cinco anos um novo modelo chamado de Psicobiológico tem sido proposto. Este modelo dá maior importância aos fatores perceptuais e motivacionais em relação aos seus antecessores, bem como a respectiva influência destes fatores no processo consciente de tomada de decisão e controle comportamental. Nesta revisão, nós apresentamos evidências experimentais e sintetizamos os pontos chaves do modelo Psicobiológico que explicam o controle da intensidade e (in)tolerância ao exercício de resistência cardiorrespiratória. Adicionalmente, nós discutimos como o modelo explica as adaptações ao treinamento relacionadas à melhora no desempenho, as manipulações experimentais e suas predições. Ao final, propomos futuras direções para esta área investigativa. O modelo Psicobiológico pode proporcionar uma nova perspectiva aos resultados anteriormente publicados na literatura, ajudando os cientistas a entenderem melhor seus problemas de pesquisa, assim como analisar e interpretar novas evidências mais precisamente.The mechanisms underpinning fatigue and exhaustion, and the specific sources of exercise-endurance intensity regulation and (in)tolerance have been investigated for over a century. Although several scientific theories are currently available, over the past five years a new framework called Psychobiological model has been proposed. This model gives greater attention to perceptual and motivational factors than its antecedents, and their respective influence on the conscious process of decision-making and behavioral regulation. In this review we present experimental evidences and summarize the key points of the Psychobiological model to explain intensity regulation and (in)tolerance in endurance exercise. Still, we discuss how the Psychobiological model explains training-induced adaptations related to improvements in performance, experimental manipulations, its predictions, and propose future directions for this investigative area. The Psychobiological model may give a new perspective to the results already published in the literature, helping scientists to better guide their research problems, as well as to analyze and interpret new findings more accurately
Autonomic correlates of Yo-Yo performance in soccer referees
[EN] We tested the hypothesis that: basal cardiac autonomic modulation (i.e. heart rate variability, HRV) was associated with the parasympathetic withdrawal during, and overall Yo-Yo IR1 performance; and therefore HRV could be used as a simple tool for specific fitness assessment. Nine sub-elite soccer referees performed the Yo-Yo IR1 until exhaustion with simultaneous recording of heart rate with the autonomic response during exercise calculated as the area under the curve (AUC). In the same week but with at least 48 hrs between days, a night-time HR recording was obtained from participants for determination of basal HRV. Correlation analysis demonstrated strong (r>0.83) relationships among Yo-Yo IR1 performance, AUC and basal HRV. These results indicate that both nocturnal HRV and AUC can be utilised as simple and valid monitoring tools of soccer referees' fitness.[TD] Nós testamos a hipótese de: que a modulação autonômica cardíaca (i.e. variabilidade da freqüência cardíaca, VFC) está associada com a retirada parassimpática durante a execução do Yo-Yo IR1; e que, portanto, a VFC poderia ser usada como uma ferramenta simples para a avaliação do desempenho físico específico. Nove árbitros sub-elite de futebol executaram o Yo-Yo IR1 até a exaustão com registro simultâneo da freqüência cardíaca e VFC para o cálculo da área sob a curva (ASC). Na mesma semana, mas com mínimo de 48 horas entre dias, obteve-se um registro noturno da FC dos participantes para a determinação da VFC basal. As análises de correlação demonstraram elevados coeficientes (r>0,83) entre o desempenho no Yo-Yo IR1, a ASC e a VFC basal. Estes resultados indicam que a VFC noturna e a ASC podem ser empregadas como ferramentas simples e válidas para o monitoramento do desempenho de árbitros de futebol
Repeated Acceleration Ability (RAA): A new concept with reference to top-level field and assistant soccer referees
PURPOSE: To perform an exploratory characterization of repeated sprint sequences (RSS) and repeated acceleration sequences (RAS) in top level soccer referees. METHODS: 7 field and 7 assistant referees were monitored during 2007 America's Soccer Cup with GPS technology. Sprints of >18 km·h(-1) and accelerations of >1.5 m·s(-2) were considered as high intensity activities. RSS and RAS were defined as a minimum of 3 consecutive bouts interspersed with a maximum of 45 s. RESULTS: Field and assistant referees performed substantially more accelerations than sprints. Neither field nor assistant referees recorded any RSS. In contrast, total distance performing RAS amounted to ∼37% and ∼20% of the total distance covered by accelerations during the entire match for field and assistant referees, respectively. Only field referees exhibited fatigue-related reductions in RAS characteristics between halves. CONCLUSION: The results of the present study would appear to support the appropriateness of a repeated acceleration ability (RAA) concept, instead of the repeated sprint ability (RSA) concept, in soccer referees. Further studies should assess RAS in referees and athletes of different team sports for designing better training exercises and physiological testing
Effects of short-term strength and jumping exercises distribution on soccer player’s physical fitness
The aim of this study was to examine the effects of a short-term (six weeks) preseason strength and jumping exercises distribution program on amateur adult soccer player’s indicators of physical fitness. Twenty male athletes (age 20.1±1.6 years) were randomly divided into two groups that completed a volume-equated training program differing only in exercises distribution: a group that completed three weeks of strength followed by three weeks of plyometric training (TT; n=10) and a group that completed six weeks of combined strength and plyometric drills (S+P; n=10). Athletes completed a triple hop test with the dominant (HOPd) and non-dominant leg (HOPnd), a 15 meters sprint, a change of direction speed (CODS) test (i.e. T test), and a 6×30 meters repeated sprint with change of direction for the best (RSCODb) and mean velocity (RSCODm), and the percentage of decrement (%Dec) in sprint time. Moreover, athletes performed a squat test for maximal power. Both strength and jumping training programs were performed two times per week, equated for exercises, frequency, volume, and intensity per session. The TT group completed the strength training volume during the first three weeks, and the plyometric training volume in the last three weeks, while the S+P combined strength and plyometric training during the six weeks. A 2 (group) × 2 (time: pre, post) ANOVA with repeated measures was used for statistical analysis. Analyses revealed significant improvements for the TT and S+P (HOPd: ES=0.91, 10.28 and 16.69%, respectively; HOPnd: ES=0.86, 11.49 and 14.71%, respectively; RSCODb: ES=0.84, 9.23 and 8.34%, respectively; RSCODm: ES=0.89, 8.56 and 7.51%, respectively). In the post-test there were no significant differences between the groups in any variable analyzed. In conclusion, both training approaches were equally effective at improving jumping and repeated sprinting ability. However, only after the S+P training approach a significant improvement in CODS was observed, with more substantial changes in maximal sprinting speed
Previous Participation In Fifa World-cup: The Key To Success?
This qualitative-descriptive investigation examining the influence exerted by experienced soccer-players on the ranking obtained from the four best-ranked by their teams in the last four FIFA World Cups (WC). They were divided into experienced-players (at least one WC participation [+1WC]) or non-experienced players (no previous participation [1WC]). Thereafter, they were classified according to their contribution in each of the playoff matches in a given WC: STARTER (started all matches); START/SUBST (started at least one match); SUBST/BENCH (did not start any matches, but replaced a player in at least one match); and BENCH (did not participate in matches). The sample was composed of 33.7% experienced and 66.3% non-experienced players. The number of players +1WC in finalist teams was significantly higher than in the non-finalist teams (p<0.05). In addition, when compared with the non-finalist teams, the finalists presented significantly higher number of players STARTER with +1WC (p<0.05). Possibly, the selection of experienced players to participate in WC may be an effective strategy to achieve better competitive performance.222737
The effect of number of players on physical demand and physiological responses during small-sided games in under-15 soccer players
The aim of this study was to analyze the effect of number of players in small-sided games (SSG) on time-motion characteristics and physiological responses in young soccer players. Fourteen soccer players from a state-level youth soccer team (age 14.4 ± 0.5 years; body mass 56.2 ± 7.0 kg; height 1.7 ± 0.1 m; BMI 20.3 ± 1.4 kg∙m-2) performed two formats (3 vs. 3 e 7 vs. 7) of the SSG. Heart rate (HR), rating perceived exertion (RPE) and blood lactate ([La]) and physical demands were analyzed using a global positioning system (GPS). Although there were not statistical differences in distance covered at different zones between SSG formats, the total distance covered, distance covered at high-speed, the quantity of high-intensity activities and quantity of accelerations >; 1.0 m∙s-2 were higher (p ; 1 m∙s-2 foram maiores (p < 0,05) no JCR 3 vs 3 (1794 m; 885 m; 69; 87, respectivamente) em relação ao JCR 7 vs 7 (1663 m; 712 m; 57; 68). O percentual da frequência cardíaca máxima (FCmáx), PSE e [La] foram superiores (p < 0,05) no JCR 3 vs 3 quando comparado ao 7 vs 7 (91,3%; 6,1 u.a.; 5,0 mmol∙L-1 vs 85,1%; 5,1 u.a.; 2,1 mmol∙L-1, respectivamente). Os resultados demonstram que a intensidade é maior durante o JCR 3 vs 3 do que no JCR 7 vs 7; além disso, a demanda física é influenciada pelo número de jogadores, com uma maior distância total e distância em alta velocidade, além de maior quantidade de atividades em alta intensidade e acelerações no JCR 3 vs 3
Training load, stress tolerance and upper respiratory tract infection in basketball players
O objetivo do estudo foi avaliar o efeito da manipulação das cargas externas\ud
sobre a dinâmica da carga interna de treinamento (CIT), a tolerância ao estresse (TE) e\ud
a severidade de episódios de infecção do trato respiratório superior (ITRS) em atletas de\ud
basquetebol, durante um macrociclo de 19 semanas, dividido em uma etapa preparatória\ud
(E1) e duas etapas de competição (E2 e E3). Os instrumentos Wisconsin Upper Respiratory\ud
Symptom Survey (WURSS-21) para o monitoramento das ITRS e o Daily Analysis\ud
of Life Demands for Athletes’ (DALDA; TE) foram preenchidos semanalmente. A CIT foi\ud
aferida a partir da percepção subjetiva de esforço da sessão (PSE da sessão). Foi detectada\ud
queda da CIT na E3, quando comparadas às etapas E1 e E2 (p < 0,05), e decréscimo no\ud
número de respostas “melhor que o normal” na parte A (fontes de estresse) e na parte\ud
B (sintomas de estresse) do DALDA, em E2 e E3, comparado com E1 (p < 0,05). Na\ud
última etapa (E3), houve incremento da severidade de ITRS (p < 0,05). Adicionalmente,\ud
correlações significantes entre TE e ITRS foram verificadas, sugerindo que a tolerância\ud
ao estresse pode modular a severidade de ITRS. Em conclusão, a manipulação da CET\ud
provocou alterações na CIT. Entretanto, ao contrário da hipótese inicial, a redução da\ud
CIT no período competitivo foi acompanhada por redução da tolerância ao estresse e\ud
aumento da severidade da ITRS. Além disso, a magnitude do estresse parece induzir o\ud
aumento da severidade de ITRSThe present study aimed to investigate the effect of external training load manipulation\ud
on internal training load (ITL), stress tolerance (ST) and upper respiratory tract\ud
infection (URTI) severity in basketball players during a 19-week macrocycle. The macrocycle\ud
was divided into three distinct phases: preparatory phase (P1) and two competitive phases\ud
(P2 and P3). The Daily Analysis of Life Demands for Athletes questionnaire (DALDA), for\ud
assessment of sources and symptoms of stress, and the Wisconsin Upper Respiratory Symptom\ud
Survey (WURSS-21), for evaluation of URTI severity, were used on a weekly basis. The ITL\ud
was assessed by Rating of Perceived Exertion (session RPE). There was a decrease in ITL at\ud
P3 when compared to P1 and P2 (p < 0.05). A decrease in “better than normal” responses in\ud
DALDA for both sources and symptoms of stress was observed at P2 and P3 when compared\ud
to P1 (p < 0.05). There was also a significant increase in URTI severity. In addition, significant\ud
relationships between ST and URTI were shown at P3, suggesting that stress tolerance may\ud
modulate URTI severity. In summary, ETL manipulation induced changes in ITL. However,\ud
unlike the initial hypothesis, a decrease in ITL during the competitive period was followed by\ud
a decrease in stress tolerance and an increase in URTI severity. Furthermore, the magnitude\ud
of stress seems to provoke an increase in URTI severit
Influence of aerobic fitness on the correspondence between heart rate variability and ventilatory threshold
The aims of this study were to verify the correspondence between heart rate variability (HRV) and ventilatory thresholds during a progressive exercise test and the relationship with low and high aerobic fitness levels. Twenty male volunteers (29.5±6.2 years; 75.9±13.0 kg; 175.0±7.4 cm) were recruited. The subjects were allocated to two groups according to their VO2max <48.8 ml•kg−1•min−1 (low cardiorespiratory fitness group) (n=10) and >48.81 ml•kg−1•min−1 (high cardiorespiratory fitness group) (n=10). A progressive test was performed, consisting of 3-min stages beginning at 25 watts and increasing by 25 watts every 3-min. The HRV threshold (HRVT) and ventilatory threshold (VT) analyses were performed through visual inspection. The comparisons with RMSSD values in percentage of maximum workload resulted in a higher effect size (ES) than the SDNN values. The VO2 in the high cardiorespiratory fitness group at VT (+32%), HRVTRMSSD (+27%), and HRVTSDNN (+31%) was signifi cantly higher compared to the group with low cardiorespiratory fitness. Higher values were observed for relative load (W•kg-1) at VT and HRVTSDNN in the high cardiorespiratory fitness group in comparison with the low cardiorespiratory fitness group (P<0.05), but no difference for VT and HRVTRMSSD. Signifi cant correlations between at VT and HRVTSDNN (r=0.77) were found only in the low cardiorespiratory fitness group. Cardiorespiratory fitness should be regarded as a factor for HRVT evaluation. The HRVTSDNN was closer to the VT in the low cardiorespiratory fitness group than the HRVTRMSSD, however, the use of vagal modulation assessed using the HRV parameter was more sensitive to observe possible differences regarding cardiorespiratory fitness.The aims of this study were to verify the correspondence between heart rate variability (HRV) and ventilatory thresholds during a progressive exercise test and the relationship with low and high aerobic fitness levels. Twenty male volunteers (29.5±6.2 years; 75.9±13.0 kg; 175.0±7.4 cm) were recruited. The subjects were allocated to two groups according to their VO2max <48.8 ml•kg−1•min−1 (low cardiorespiratory fitness group) (n=10) and >48.81 ml•kg−1•min−1 (high cardiorespiratory fitness group) (n=10). A progressive test was performed, consisting of 3-min stages beginning at 25 watts and increasing by 25 watts every 3-min. The HRV threshold (HRVT) and ventilatory threshold (VT) analyses were performed through visual inspection. The comparisons with RMSSD values in percentage of maximum workload resulted in a higher effect size (ES) than the SDNN values. The VO2 in the high cardiorespiratory fitness group at VT (+32%), HRVTRMSSD (+27%), and HRVTSDNN (+31%) was signifi cantly higher compared to the group with low cardiorespiratory fitness. Higher values were observed for relative load (W•kg-1) at VT and HRVTSDNN in the high cardiorespiratory fitness group in comparison with the low cardiorespiratory fitness group (P<0.05), but no difference for VT and HRVTRMSSD. Signifi cant correlations between at VT and HRVTSDNN (r=0.77) were found only in the low cardiorespiratory fitness group. Cardiorespiratory fitness should be regarded as a factor for HRVT evaluation. The HRVTSDNN was closer to the VT in the low cardiorespiratory fitness group than the HRVTRMSSD, however, the use of vagal modulation assessed using the HRV parameter was more sensitive to observe possible differences regarding cardiorespiratory fitness
Effects of Different Post-Activation Potentiation Warm-Ups on Repeated Sprint Ability in Soccer Players from Different Competitive Levels
[EN] This study aimed to compare the effects of a traditional warm-up with two post-activation potentiation (PAP)
warm-up strategies on the repeated sprint ability (RSA) of soccer players from national (NL) and regional (RL)
competitive levels. Sixteen young players (NL, n = 8, age = 20.7 ± 1.4 y, body mass = 68.5 ± 7.0 kg, body height = 177.4
± 5.2 cm; RL, n = 8, age = 20.8 ± 1.0 y, body mass = 68.7 ± 4.0 kg, body height = 176.6 ± 5.6 cm) were recruited to
complete a traditional warm-up (CONTROL), a PAP warm-up incorporating squats with a load (~60% 1RM) that
allowed a high speed (1 m/s) of movement and a high number of repetitions (PAP-1), and a PAP warm-up with a load
(~90% 1RM) that allowed a moderate speed (0.5 m/s) of movement and a reduced number of repetitions (PAP-0.5). A
RSA test (six 20-m sprints with 20 s of recovery) was performed 5 min after the PAP warm-up to assess the effects of
the different protocols on the fastest sprint (RSAb) and the mean time of all sprints (RSAm). A meaningful
improvement of RSA performance was observed with PAP-0.5, attaining a large effect on NL (RSAb, ES = -1.5; RSAm,
ES = -1.3) and only a small effect on RL athletes (RSAb and RSAm, ES = -0.2). Moreover, when each RSA sprint
performance was compared between NL and RL players, after PAP-0.5 greater performance for all sprints was observed
in the NL players. Therefore, adding a heavy strength-based conditioning exercise during the warm-up prior to a RSA
test may induce significant performance improvements in NL, but only small effects in RL players.S
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