There is a lack of knowledge about correct exercise progression during core training, especially if it is necessary to choose between different devices.PURPOSE: To compare core muscular activity during nine exercises performed in stable and unstable conditions.METHODS: 20 physically fit and healthy female subjects took part in a randomized, within-subject design assessment. The maximum isometric voluntary contraction (MIVC) was evaluated for the normalization of the electromyographic signal. Lumbar erector spinae (LES), thoracic erector spinae (TES), lumbar multífidus (LM), thoracic multífidus (TM) and gluteus maximus (GM) muscular activities were recorded, and then the average root mean square values were calculated for each condition. Surface electromyography activity was analyzed during the central 16 seconds of 20 in the 9 isometric standing postures (140° and 60° of knee and hip flexion, respectively), with the arms flexed parallel to the floor. Three positions: (a) bipodal, (b) unipodal and (c) unipodal with a long handle and two Thera-Band red elastic tubes were performed in three conditions: (a) stable, (b) Thera-Band Soft Stability Trainer and (c) Thera-Band Rocker Board. Mean %MIVC of the 5 muscles were compared using a mixed-model MANOVA with a Bonferroni post-hoc analysis. Significance level was set at p≤0.05.RESULTS: Significant differences in core muscle activation were found between conditions (p<0.001) (See Table 1).CONCLUSION: Unipodal position and elastic tubes always provoked a significantly higher level of muscular activation in the core independently of the unstable device used and/or the body position.