Universidade Estadual de Londrina

About: Universidade Estadual de Londrina is a education organization based out in Londrina, Brazil. It is known for research contribution in the topics: Population & Toxoplasma gondii. The organization has 13052 authors who have published 19291 publications receiving 212123 citations.

Training for Power and Speed: Effects of Increasing or Decreasing Jump Squat Velocity in Elite Young Soccer Players.

Abstract: The aim of this study was to test the effects of 2 different velocity-oriented power training regimens by either increasing or decreasing the jump squat velocity during jump training sessions applied 3 times a week for 6 weeks in soccer players. Twenty-four elite under-20 soccer players were randomly assigned to an increased bar velocity group (IVG) or a reduced bar velocity group (RVG). Athletes had their countermovement jump heights, mean propulsive velocities (MPVs) in jump squat, leg press maximum dynamic strength (1 repetition maximum [RM]), 20-m sprint times, and zig-zag change of direction (COD) abilities assessed before and after the intervention. Performance in all tests improved after training in both groups. However, greater gains in 1RM and MPV using 50�90% of body mass (BM) were noted for the RVG. The IVG demonstrated greater improvements in speed at 5, 10, and 20 m and MPV with no additional external load and with 40% BM. Both groups improved similarly in countermovement jumps and COD. To conclude, both velocity-oriented power training regimens were effective in eliciting neuromechanical adaptations, leading to better strength/power/speed performances, and the choice as to the most suitable method should be tailored according to players' needs/deficiencies.

[The Baby-Friendly Hospital Initiative and breastfeeding in a neonatal unit].

Abstract: OBJETIVO: Avaliar o impacto da iniciativa Hospital Amigo da Crianca sobre a pratica do aleitamento materno durante a internacao de recem-nascidos em unidade de neonatologia e durante os primeiros seis meses de vida. METODOS: Foram consultados todos os prontuarios de recem-nascidos internados em unidade de neonatologia de um hospital de ensino durante os anos de 1994 (N=285) e 1998 (N=368). Foram analisadas informacoes sobre o regime alimentar durante a internacao e apos a alta hospitalar, ate os primeiros seis meses de vida. Para estimar a duracao do aleitamento materno e do aleitamento materno exclusivo e as diferencas entre os dois anos, foram utilizados a tecnica de Kaplan-Meier e o teste de Log-Rank. Analises de regressao logistica e de Cox foram aplicadas para controlar variaveis de confusao. RESULTADOS: Durante o periodo de internacao, houve aumento expressivo do percentual de criancas em aleitamento materno exclusivo (de 1,9%, em 1994, para 41,7%, em 1998) e alimentacao exclusiva por formula, que era de 17,9%, em 1994, e deixou de existir em 1998. Quanto a amamentacao nos primeiros seis meses de vida, o tempo mediano do aleitamento materno exclusivo aumentou de 12 para 45 dias. Para o aleitamento materno, que inclui a ingestao de outros alimentos, nao houve diferenca significativa. CONCLUSOES: A implantacao da iniciativa do hospital estudado contribuiu para aumentar o indice de aleitamento materno exclusivo durante a internacao de recem-nascidos em uma unidade de neonatologia e nos primeiros seis meses de vida.

A Correlational Analysis of Tethered Swimming, Swim Sprint Performance and Dry-land Power Assessments.

Abstract: Swimmers are often tested on both dry-land and in swimming exercises. The aim of this study was to test the relationships between dry-land, tethered force-time curve parameters and swimming performances in distances up to 200 m. 10 young male high-level swimmers were assessed using the maximal isometric bench-press and quarter-squat, mean propulsive power in jump-squat, squat and countermovement jumps (dry-land assessments), peak force, average force, rate of force development (RFD) and impulse (tethered swimming) and swimming times. Pearson product-moment correlations were calculated among the variables. Peak force and average force were very largely correlated with the 50- and 100-m swimming performances (r=− 0.82 and −0.74, respectively). Average force was very-largely/largely correlated with the 50- and 100-m performances (r=− 0.85 and −0.67, respectively). RFD and impulse were very-largely correlated with the 50-m time (r=− 0.72 and −0.76, respectively). Tethered swimming parameters were largely correlated (r=0.65 to 0.72) with mean propulsive power in jump-squat, squat-jump and countermovement jumps. Finally, mean propulsive power in jump-squat was largely correlated (r=− 0.70) with 50-m performance. Due to the significant correlations between dry-land assessments and tethered/actual swimming, coaches are encouraged to implement strategies able to increase leg power in sprint swimmers.

High-Speed Resistance Training in Older Women: The Role of Supervision.

Abstract: Older women participated in a 12-week high-speed resistance training program under two supervisor-to-subject ratio methods (i.e., high versus low supervision) to assess its effects on muscle strength, power, functional performance, and quality of life assessed before (T1) and after (T2) intervention. Women were divided into either the control group (CG, n = 15), high supervision group (HSG, n = 30), or low supervision group (LSG, n = 28). The training program included exercises requiring high-speed concentric muscle actions. No differences were observed among groups at T1. Between T1 and T2, the HSG showed a higher (p < .05) improvement in muscle strength (ES = 0.36-1.26), power (ES = 0.5-0.88), functional performance (ES = 0.52-0.78), and quality of life (ES = 0.44-0.82) compared with LSG and CG. High-speed resistance training under closer supervision is more effective for improving muscle strength, power, functional performance, and quality of life in older women.