Investigating the effects of resistance training on body composition and maximum strength of the upper body muscles of sitting female volleyball players

Academic thesis for obtaining a master's degree

Abstract

Key words: resistance training, body composition, muscle strength, muscle endurance, muscle volume

1- 1. Introduction

By examining and carefully in different sports, in most of them we will see skills and movements that require a lot of high physical fitness, strength and speed (2). Sitting volleyball [1] is one of those sports that players need high physical fitness to achieve excellence in high-level competitions. To reach this level of preparation, strength is one of the important and effective factors (130).         

     In all recorded historical texts, the ability to generate power has fascinated man. Although modern technology has reduced the need for maximum strength levels for normal daily activities, from a scientific and clinical point of view muscle strength is of particular importance for health (43), optimal sports performance (174) and increased quality of life [2] (147). The conducted research shows that resistance training is a method for developing health, general fitness and developing skeletal muscle strength (30). Today, resistance exercises are used for the purpose of physical fitness and increasing life expectancy in non-athletes (131). In the past, resistance training was performed by a small number of people (such as strength athletes and bodybuilders), today resistance training is recommended for the general public by prestigious international organizations such as the American College of Sports Medicine [3] and the American Heart Association [4]. Muscular strength and endurance resulting from resistance training is of special importance for the general health and physical fitness of people, and it improves people's ability to participate in leisure physical activities as well as easier implementation of daily life activities, and makes people maintain functional independence for a longer period of their lives. Resistance exercises are necessary for the development of the muscular system (29).

The key to successful action in resistance training at any level of preparation or any age is the use of a designed program so that the adaptations created from resistance training are aimed at improving the specific goals of the desired exercise (66). To design a resistance training, it is necessary to pay attention to primary variables such as intensity (load) and training volume (67). Through appropriate manipulation of program variables of resistance training such as type of training, number of sets, choice of resistance, number of repetitions or rest between training periods, various programs can be designed for people with different preparation. For example, the need to develop strength in people who exercise for health is moderate. Muscular endurance and hypertrophy [5] is sufficient for this group at the level of general fitness, but for elite athletes, exercises should be done that the athlete can achieve maximum strength, muscular endurance or hypertrophy (100).

Since sitting volleyball is a strength-speed sport, resistance training is necessary to improve the athlete's performance, and since the execution of techniques and skills at a high level requires high muscle strength. (138) In this research, an attempt is made to investigate the effect of resistance training program on maximal strength, body composition, endurance, and muscle volume in female sitting volleyball players of Isfahan.

2-1. Statement of the problem

It should be noted that disabled people have less ability than healthy people due to the complications caused by disability, and for this reason, they are subject to injury. The participation of disabled people in sports competitions multiplies the possibility of their injuries. Some sports injuries also occur only in disabled athletes (117). Gaining strength reduces the risk of vulnerability in athletes (106).

Most disabled people rely on their upper limbs to move and move, and often perform daily tasks and most sports activities with this limb (111). On the other hand, sitting volleyball activities are very difficult. The rule of sitting is considered as the primary source and shows that movement without the ball, participation in games is one of the most important things in this sport. The fact that they sit on the ground and play does not mean that these players are not able to move; Because the ball and the direction of movement of the variable forces make the players move to the side, forward or backward [8]. The movement is as fast as possible to obtain the investigated methods to receive the ball using the influence of the upper body muscles at any time during the game, especially since the area of ??the field (10 meters long x 6 meters wide) makes the performance more difficult, which requires more muscle power to execute movement skills (35). Maximum strength and explosive power are among the most important factors of muscle preparation for optimal performance of sports skills such as jumping, increasing speed in minimum time, changing direction and turning (80). Muscular strength plays a great role in optimal performance of daily life and work activities and especially the effective performance of athletes (67). Yesis [9] stated that most of the activities of athletes need speed and strength. However, Waten [10] considers the importance of speed and strength to be different according to the sport and game position (23).  Resistance training is one of the types of sports activities that, in addition to developing strength, power, and muscular endurance (100), is also common in rehabilitation programs for patients with muscle injuries and disorders. Resistance training increases the production of contractile proteins and muscle hypertrophy, especially in fast-twitch tissues [11], increases fat-free mass [12] and decreases body fat percentage (103). On the other hand, a lot of evidence shows that resistance training is a very important part of sports recommendations for weight loss. However, it seems that the changes caused by resistance training are more beneficial for men (88). Compared to men, women, 55% in the upper body, and 72% in the lower body, have less resistance (130), because the hormone testosterone [13], which plays the main role in hypertrophy and muscle strength, is naturally 10 times higher in men at rest than in women (157). Weight training increases the amount of this hormone in men's blood, while in women, weight training has little effect on increasing this hormone (74).