Auxiliary muscles and slow component during rowing

The aim of this study was to investigate the contribution of the auxiliary muscles, utilized to sustain the subject's position on the ergometer, to the oxygen uptake slow component phenomenon. Three tests were performed at the same severe relative intensity on a rowing ergometer: a standard rowing exercise test, a rowing exercise performed with the arms and one performed with the legs only. During the three exercise modalities, oxygen uptake, local oxyhemoglobin saturation and surface electromyography signals of the trapezius and vastus lateralis muscles were measured. The slow component amplitude, in absolute values, resulted statistically lower for rowing (343.9 ml . min (-1)) than for arms (795.6 ml . min (-1)) and legs (695.8 ml . min (-1)) exercise modes. The same result was found when the slow component amplitude was calculated as percentage of V O (2peak) (7.1 % for rowing; 17.2 % for arms; 17.3 % for legs). The lower slow component amplitude measured for the rowing exercise mode with respect to both arms and legs modes, demonstrates that the auxiliary muscles involved in the exercise contribute to the increasing energetic cost due to the slow component.