In order to improve performance in sport activities, functional or structural modifications can be produced in our organism with specific motor training activities. In Sports Medicine is essential to objectively evaluate the obtained results to have a precise estimation of the efficacy of motor training. The aim of our work was to verify, by means of selected electromyographic methods in addition to evaluation of body characteristics and psycho-motor capacity, such as measurement of body weight, body fat mass and cycloergometric evaluations, if it is possible to obtain information about changes in muscle structure and function after specific motor training. In six men, aged 21-31 years old, who lead sedentary lives before the beginning of the tests, evaluation of body and motor physical characteristics was performed before and after a motor training period. Three subjects were trained for endurance aerobic performance, and the other three for power anaerobic one. The endurance-trained (ET) group underwent an eight-weeks period of jogging on flat ground. Exercise was performed at such intensity to utilize only aerobic metabolic pathways. The power-trained (PT) group was trained to stimulate phasic muscular activity, of lactacid and not-lactacid type. These subjects were trained with the so-called 'Freiburg interval training' and received also a dietologic oral integration consisting of 10 g of branched chain amino acid (BCAA) to take before and after training sessions. At the beginning and at the end of this specific training period were performed A) body weight measurement and BIA (Bioelectric Impedance Analysis) test with calculation of body fat mass, B) specific athletic performance evaluated according to the type of physical training, that is chronometric test of 3000 metres on a track fro ET group and of 100 metres for the PT group, C) cycloergometric tests with calculation of leg-extensor-muscles power capacity and indirectly of maximal O 2 body intake capacity, finally D) automatic analysis of surface EMG of the tibialis anterior muscle during 60 sec of voluntary and electrically stimulated fatiguing contractions, as indirect method to determine muscle fibre-type constitution throught measurement of muscle fiber conduction velocity and power spectral parameters. All these tests showed training induced modifications, greater in subjects with lower starting results. So, besides improvements in global physical and specific muscular capacity, our electrophysiological results suggest that the training was able, at least in part, to modify muscular byoelectric characteristics. In conclusion, the recent development of non-invasive techniques of surface EMG measurements and analysis allowed us to perform neuromuscular characterization of physically active subjects and to evaluate training effects on motor performance. Naturally further studies are necessary to match the modified muscle functional characteristic to the underlying structural events.
|Autori:||Bianchi S; Rossi B; Siciliano G; Manca L|
|Titolo:||Quantitative evaluations of systemic and neuromuscular modifications induced by specific training in sedentary subjects|
|Anno del prodotto:||1997|
|Appare nelle tipologie:||1.1 Articolo in rivista|