Borislav Obradovic

Short-term isokinetic training versus isotonic training: effects on asymmetry in strength of thigh muscles.

Short-Term Isokinetic Training Versus Isotonic Training: Effects on Asymmetry in Strength of Thigh Muscles The aim of this study was to investigate the effects of two training protocols on the isokinetic performance of athletes. The study was conducted in 38 athletes, (age 23.3 ± 3.6 years) participating in national level leagues of different sports, whose initial concentric hamstrings-to-quadriceps (conH/Q) torque ratio was lower than 0.5. During seasonal testing, an isokinetic measurement of knee extensors and flexors was performed at 60º/s. The athletes were divided into two groups. Nineteen athletes performed the isokinetic training protocol (IT) while the second group of 19 athletes followed the isotonic training protocol (RT). Both protocols lasted 4 weeks. After completing the training protocols, both groups underwent a final isokinetic testing. The isokinetic data revealed significant increases after training in measures of peak torque in both extensor and flexor muscle groups, in both the IT and RT study groups (p < 0.05). There were significant increases (p< 0.05) in conH/Q ratio in both groups after the implemented protocols, but greater in IT group. Consequently, applied IT protocol induced changes in working muscles, thereby restoring detected asymmetry to an acceptable balance more efficiently compared to RT protocol.

ADAPTED PHYSICAL ACTIVITY IN THE PREVENTION AND THERAPY OF OSTEOPOROSIS

INTRODUCTION Osteoporosis, a disease characterized by the progressive loss of bone tissue, is one of the most common complications of aging. EPIDEMIOLOGY According to some calculations, there were 25% of women and 4% of men older than 50 years with osteoporosis in the world in 2010. It is assumed that the number of patients with osteoporosis will increase by 30% in every 10 years in the 21st century. There are many reasons for that: the worlds population is growing older, diet is getting poorer in vitamins and minerals and physical activity is decreasing. THE QUALITY AND QUANTITY OF BONE TISSUE: Developing bones are much more responsive to mechanical loading and physical activity than mature bones. This suggests that training in early childhood may be an important factor in the prevention of osteoporosis in later life. It is important to note that the quality of bone achieved by training at younger age cannot be maintained permanently if it is not supported by physical activity later in life. Adapted physical activity represents physical activity individually tailored according to the psychosomatic capabilities of a person and the goal to be achieved. It can be applied at any age in order to maintain strong bones and reduce the risk of fracture. Adapted physical activity is different for men and women, for different age, as well as for the individuals. Aerobic exercises, which lead to an acceleration of breathing, increased heart rate and mild perspiration, as well as resistance exercises and exercises against resistance done by stretching elastic bands, for hands, legs and torso have been proven to increase bone density and improve bone strength. Coordination and balance exercises are important in an individual workout program. An explanation of the action of adapted physical activity is the basis for the theory of control and modulation of bone loss, muscle strength, coordination and balance. Physical activity is very effective in reducing sclerostin, which is known to inhibit bone formation. In addition, physical training enhances the levels of insulinlike growth factor, which has a very positive effect on bone formation. CONCLUSION The aim of adapted physical activity is to improve bone formation in youngsters, to preserve the bone mass in adults and to prevent the bone loss in the elderly thus reducing the risk of falls and resulting fractures; in other words, to minimize the disability caused by fractures and improve the quality of life.

Lumbar and Abdominal Muscles Isometric Potential in Volleyball Cadets

Al considerar que un partido de voleibol requiere cierto nivel de caracteristicas antropologicas individuales de los jovenes jugadores de voleibol para actuar con exito en condiciones situacionales, el enfoque interdisciplinario principal en el estudio de las ciencias del deporte es la orientacion metodologica, como tambien lo es el estado antropologico de los jugadores. El objetivo de este estudio fue analizar las posibles diferencias en la columna lumbar y el potencial isometrico en los musculos abdominales masculinos y femeninos. En la muestra fueron incluidos 42 sujetos (15 varones y 27 mujeres) jugadores de voleibol masculino y femenino de la seleccion cadete de Serbia, de 14±0,5 anos. Se realizo evaluacion del potencial muscular utilizando cuatro tareas de movimiento de motor estandarizados en las siguientes areas: la contraccion estatica de los flexores del torso, de contraccion estatica de los extensores del tronco, contraccion estatica del flexor izquierdo del torso, y la contraccion estatica del flexor derecho del torso. Ademas de las estadisticas descriptivas y las estadisticas de base utilizadas, se uso la prueba t para las muestras independientes para comparar los valores medios de los parametros medidos en dos grupos diferentes de los deportistas - jugadores de voleibol (ninas - ninos). Los indicadores descriptivos de la muestra sugieren mayores valores de potencial isometrico de los musculos espinales profundos en ninos en todas las variables del estudio. Los resultados del estudio obtenidos por la prueba t de muestras independientes indicaron que existe una diferencia estadisticamente significativa entre los resultados medios en las variables de los flexores del tronco y en las contracciones estaticas de los extensores del tronco, en el nivel de 0,001. Con otras dos variables, los valores indicaron que la diferencia entre ambos sexos no es significativa pero es accidental. Los resultados de este estudio con respecto a la contraccion estatica del lado derecho y flexores laterales izquierdos del torso muestran la falta de significacion estadistica entre los jugadores masculinos y femeninos de voleibol.

Effects of group exercise on functional abilities: Differences between physically active and physically inactive women

BACKGROUND Aerobic exercises to music can have a positive effect on functional and motor skills of an exerciser, their health, as well as an aesthetic and socio-psychological component. OBJECTIVE The objective of this study was to determine the effects of reactive exercising in a group on functional capabilities in physically active and physically inactive women. METHODS A prospective study included 64 healthy women aged 40-60 years. The sample was divided into the experimental group (N= 36), i.e. physically active women who have been engaged in recreational group exercises at the Faculty of Sport and Physical Education, University of Novi Sad, Serbia, and the control group (N= 28), which consisted of physically inactive women. All the participants were monitored using the same protocol before and after the implementation of the research. All women had their height, weight and body mass index measured as well as their spiroergometric parameters determined according to the Bruce protocol. RESULTS A univariate analysis of variance has shown that there is a statistically significant difference between the experimental group and the control group in maximum speed, the total duration of the test, relative oxygen consumption, absolute oxygen consumption and ventilation during the final measurement. After the training intervention, the experimental group showed improvements in all the parameters analyzed compared with pretest values. CONCLUSION The recreational group exercise model significantly improves aerobic capacity and functioning of the cardiovascular system. Therefore, it is essential for women to be involved more in any form of recreational group exercising in order to improve functional capacity and health.