162 Introduction Flexibility is an element of physical fitness, which particularly determines an individual’s wholesomeness and independence [1]. Like other physical features, flexi- bility may be trained at submaximal intensity (stretch- ing), performed within the normal range of motion and slightly forcing for 4 to 6 seconds, or at the maximal intensity (flexibilizing), performed with discomfort on the pain threshold for at least 10 to 15 seconds. In flexi- bility training, ballistic, proprioceptive neuromuscular facilitation (PNF), and static methods are traditionally used, with the latter having greater applicability [2]. Flexibility training has been used by athletes to pre- vent lesions and enhance athletic performance [2–4]. Nevertheless, its use in isolation as preparation for exer- cise is unlikely to prevent lesions and may even hamper performance in sports involving strength and power [5]. Static flexion prior to physical activity has been shown to reduce force production and power output [6–9], inhibit dislocation speed [10]. Likewise, Bezerra et al. [11] have demonstrated that PNF exerts a negative acute influence on force resistance. On the other hand, there are investigations pointing to a favorable in- fluence of stretching exercises on performance [3, 12, 13]. On the other hand, the results with constant training in sports without stretching also decrease maximal power output of lower extremities [14]. These results may be conflicting due to the lack of intensity standardization of flexibility training. There- fore, the aim of this study was to investigate changes in the performance levels of explosive force in young adult women when the same muscle group previously underwent flexibility exercises (stretch & flex) of diffe- rent intensities. Material and methods Subjects Twenty-five active in strength training adult women (aged 28.2 ± 3.5 years; height 162.2 ± 1.4 cm; body EFFECTS OF DIFFERENT INTENSITIES OF FLEXIBILITY TRAINING ON EXPLOSIVE FORCE LEONARDO ANTôNIO DOS SANTOS GALDINO 1 * , CARLOS JOSé NOGUEIRA 1 , ELOíSA COSTA E SILVA GALDINO 2 , JORGE ROBERTO PERROUT DE LIMA 3 , RODRIGO GOMES DE SOUZA VALE 1 , ESTéLIO HENRIQUE MARTIN DANTAS 1, 4 1 Human Motricity Biosciences Laboratory (LABIMH), Federal University of Rio de Janeiro (UNIRIO), Brazil 2 Salgado de Oliveira University (UNIVERSO), MG, Brazil 3 Faculty of Physical Education and Sports (UFJF), MG, Brazil 4 Invited Research of Laboratory of Physical Activity and Health, University of Valencia, Spain ABSTRACT Purpose. To verify whether there are changes in the performance levels of the explosive force when the same muscle group previously under- went different intensities of flexibility training (stretch & flex). Basic procedures. The tests were performed with 25 females on three consecutive days and were preceded by a 10-minute warm-up period. First, each participant performed a maximum vertical jump on a contact platform. The jump was repeated after 10 minutes, and the first day was considered the control (C). On the second day, a routine of stretching exercises (S) was included, and on the third day, the same routine, but intensified with a maximum static stretching exercises (flexibilizing – F), was used. Main findings. The height reached in the control jump decreased by 0.17%, showing no influence on the performance when the jump happened on the same day, with a time-interval of only 10 minutes ( p = 0.903). On the day of the stretching routine, there was a reduction of 3.6% ( p = 0.001), and on the third day with flexibilizing, there was a 6.8% reduction ( p = 0.001). A comparison of the groups showed no significant differences between them. Conclusions. The jumps after the two stretching routines were significantly lower. Submaximal or maximal (flexibilizing) stretching exercises reduced the explosive force of vertical jumps, although the differences between the training intensities were not significant. Key words: flexibility, stretching, warm-up, vertical jump doi:10.2478/v10038-010-0015-1 2010, vol. 11 (2), 162–166 * Corresponding author. Unauthenticated Download Date | 11/14/14 6:34 PM