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Official Journal of the Italian Sports Medicine Federation
Indexed/Abstracted in: BIOSIS Previews, EMBASE, Science Citation Index Expanded (SciSearch), Scopus
Impact Factor 0,163
Online ISSN 1827-1863
Degree course in Science of Motor and Sports Activities, University of Foggia, Foggia, Italy
Aim. The paper aims to describe the performance levels related to the capacity for explosive strength, reactive strength and speed of young football players who have been presented with different initial conditioning protocols.
Methods. The sample of young football players (n=48) was broken down into two groups, an experimental group (n=27) and a control group (n=21). The experimental group was then divided into two smaller groups (static stretching protocol n=15 and speed protocol n=12). A conductance platform was used for Counter Movement Jump (CMJ), Drop Jump (DJ), and Counter Movement Jump free arm (CMJ as) protocols, to assess the reactive strength and explosive strength components of the lower limbs. A 20 m test was performed for speed, from a standing start, measured by photoelectric cell, while the seated tapping test was used to measure rapidity.
Results. For the GC the CMJ revealed average values (±ds) of 31.6±3.7 cm; for the GSS average values of 33.2±4.2 cm; for the GSR average values of 34.4±4.1 cm (p<0.05). The CMJas revealed for the GC, GSS and GSR values of 38.8±4.3 cm, 38.0±5.6 cm and 39.6±3.5 cm respectively, without any statistically significant difference. In the DJ referred to jump height values of 27.0±4.3 cm, 30.4±4.3 (p<0.05) cm and 30.8±4.3 cm (p<0.03) were measured respectively for the GC, GSS and GSR; in reference to the contact time, values of 285.1±58.6 ms, 304.1±63.7 ms and 250.1±41.3 ms (p<0.05) were measured respectively for the GC, GSS and GSR. In the 20m test, values of 3.7±0.3 sec, 3.5±0.2 sec and 3.3±0.2 sec (p<0.001) were measured respectively for the GC, GSS and GSR.
The seated tapping test for both feet did not reveal statistically significant differences between the three groups observed.
Discussion: The data reveal that a warm-up protocol made up of rapidity exercises for the lower limbs may give a better performance for jumps with counter-movement and for acceleration over 20 metres, compared to someone who adopts a traditional warm-up protocol or one made up primarily of active static stretching exercises. This trend is also confirmed in the reactive strength performance measured by drop jump. The most interesting aspect regards the difference between the contact times which take on a decisive importance in the context of performance related to sport: the GSR obtained values significantly lower (p<0.05) than the GSS, probably supported by a more effective temporary recruitment capacity and greater muscular stiffness.
Conclusion. The differences in the CMJas and in the tapping test are not significant, probably because of the involvement of coordinative patterns that are not strictly influenced by the different warm-up protocols. The acute effects of active static stretching seem to negatively condition muscular stiffness and a young football player’s capacity for acceleration.
language: English, Italian