[en] On small model superconducting coils placed in external magnetic field high mechanical stresses proper to large superconducting magnet systems (SMS) have been reproduced. The effect of winding mechanical properties on their training and limiting current values has been investigated. It is confirmed that the winding deformation at helium temperature is of a jump-type nature and accompanied by heat release which cause transition in the normal state. Training and degradation correlation with a non reversible and reversible components of the winding material deformations has been found out. The mechanism training and degradation of superconducting magnets is suggested. This mechanism enables planning possible ways of undesirable phenomena decrease for account of deformation heat release decrease: limiting of possible winding deformations, creation of windings at elastic deformation of which heat release does not exceed a definite critical value (selection of gasket material and conductor insulation etc...) It is shown as well that self-banding either in round or oval windings leads to limiting magnet current increase