Cubetti di Sapere<\/em><\/a>, the suspension plank mode involving the arms inside the TRX allows, in comparison to the mode with the feet inside the TRX, an activation of the rectus abdominis about 20 per cent greater and of the external oblique muscles 12 per cent greater.<\/p>\n\u00abBoth modes are still more effective in activating the abdominal muscles than the floor plank. Surprisingly, the use of a double instability, with arms and legs inside the TRX, does not seem to lead to to an additional level of activation of the abdominal muscles compared to the mode of execution with the arms in the TRX – explains Federico Donghi, head of the Training Department at the Mapei Sport Research Centre. – So a good progression for this exercise could be: plank on the ground, plank in suspension with the legs and plank in suspension with the arms\u00bb.<\/p>\n