THE IMPACT OF PLYOMETRIC STRENGTH TRAINING ON THE 50 M FREESTYLE PERFORMANCE IN 16-17 YEARS OLD SWIMMERS

Abstract

The aim of this study was to investigate the effect of long-term combined speed-strength and plyometric training on explosive power and 50 m freestyle performance in young swimmers (16–17 years) applied during the pre-competition period. Therefore, we studied the literature on this topic and the methods used in previous research papers. We developed and implemented an experimental methodology for the long-term combined speed-strength and plyometric training based on the theory of potentiation after activation (Post-activation Performance Enhancement - PAPE). This theory suggests, that muscle performance increase after voluntary muscle activation in the following 6-8 minutes. We used biomechanical expediency for this type of sports exercise. We analyzed the results of speed-power and plyometric tests and determined the influence on 50 m freestyle performance. The purpose of the study is to determine the main factors that influence the explosive power of the swimmers studied and the influence of low-volume and speed-strength training on the achievement in the 50 m freestyle. Competitors from the M.G.S. Panseraikos swimming club from Serres, Greece participated in the study. Sixteen athletes (n=8 girls and n=8 boys) participating in the Greek Swimming Championships, signed are informed consent statement. The study was conducted in the indoor Municipal Swimming Pool of Serres, Greece, with sizes 25/12.5 m. The anthropometric data were measured with a TANITA RD-545 Body Analyzer and a Go Pro HERO 11 Black Cinematic 5.3K60 video camera and software GraphPad Prism version 3.0 for statistics. Anthropometric parameters in boys showed the following values (M±SD), age 16.38±0.52 y, weight 65.40±3.36 kg, height 172.1±2.90 cm, arm span 181.3±2.61 cm and body fat 12.6%±2.03. For girls, the data were age 16.63±0.52 y, weight 62.76±3.41 kg, height 165.8±4.20 cm, arm span 175.8±6.36 cm and body fat 16, 20 ±1.4%. Both groups participated in routine water training (1.5-2 hours per day). Methodology - Participants in the experimental group had a 20-week speed-strength training program that included upper and lower body exercises aimed at increasing explosive power, unlike the control group. Training with Plyometric exercises includes, 1) squat (SQ); 2 squat jump (SJ); 3) countermovement jump (CMJ); 4) bench press (BP); 5) pull ups (PU); 6) shoulder press (SP). Testing was performed before and after the 20-week exercise intervention using the following tests: 1) medicine ball put (MBP); 2) half-squat (HS); 3) vertical jump (VJ); 4) 50 m freestyle. Results - 1) medicine ball put from the chest, increase in girls - 13 cm., 2) half-squat increase in boys 0.030 sec., 3) vertical jump 2.5 cm, 4) 50 m freestyle - increase 2.88 sec. We found a positive effect and an increase in the results of the experimental group in speed-strength tests, after the application of a methodology including plyometric speed-strength training with light weights, a low number of repetitions per set and maximal lifting velocity. We recommend conditioning coaches and narrow swimming specialists to apply a similar kind of speed-strength training in combination with plyometric exercises, especially in the preparation and pre-competition period of preparation. We also recommend coaches to use a wide range of exercises to develop the 'start' and 'turn' elements because the explosive power of the lower limbs accompanied by the action of the upper limbs helps to better underwater propulsion and get into 'swimming velocity" for to be improved the final score.