Résumé :
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Aging is characterised by a gradual decrease in muscle mass and muscle strength which contributes to a decline in physical functions, increase disability, frailty, and loss of independence. Age related loss of muscle mass is referred to as sarcopenia (Argiles JM et al., Adv Gerontol.18:39-54,2006). Regular training programs are a concrete means to prevent and/or reduce functional decline due to aging (ACSM, Med Sci Sports Exerc.1998 Jun;30(6):992-1008), although the optimum regime specific for older adults remains unclear. Twenty-eight subjects (12? and 16?) of 75±10 years old with a diagnosis of grade 3 Sarcopenia (CDC) were randomly assigned to three different training programs, 3 day/wk for 12 wk, high intensity local vibrational program (intensity: 300hz), endurance program (intensity: 60-70% HRmax) and resistance program (intensity:60-80%Fmax, 10-12 repetitions for 3sets). Before and after the training programs a muscle samples were collected from vastus lateralis muscle by biopsy. These were used to analyse the specific tension development of single fibers. At the same time, the Isometric lower limb force was measured by dynamometer. The Myoton-2 equipment was used to describe the viscoelastic parameters of the skeletal muscles: the frequency of damped mechanical oscillation of the muscle tissue (Hz), logarithmic decrement of the oscillations (?) and stiffness (Nm-1) of the muscle tissue. As follow-up the subjects was tested 3 months after protocol end. Our results indicate that resistance and vibrational training increase muscular strength(p<0.05). This improvement was maintained at 3 months. This study shows increase of muscular elasticity and muscular tension. Variation in muscular stiffness is not significant. The relation between strength, the viscoelastics parameters and the specific tension of fibers have been analysed. In conclusion, different training programs cause specific adaptation in muscles in the elderly. Resistance and vibrational programs seem to have better results in counteracting muscles decline due to aging.
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