Eccentric cycling involves greater mental demand and cortical activation of the frontoparietal network

Eccentric, compared to concentric muscle contraction, is thought to be attributed to different strategies of neuro-motor processing and a higher level of mental demand. This study aimed to evaluate the mental demand and related-cortical activation patterns to eccentric and concentric cycling at matched perceived effort and torque. Nineteen healthy men (30±6 yrs) performed four different 5-min cycling exercise conditions on a semi-recumbent isokinetic cycle ergometer: 1) concentric at a moderate perceived effort (23 on the CR100® scale) without torque feedback; 2) concentric and 3) eccentric at the same average torque produced in the first condition; and 4) eccentric at the same moderate perceived effort than the first concentric condition. The order of conditions 2-4 was randomised. After each condition, mental demand was monitored using the NASA-TLX scale. Changes in oxy- (O2Hb) and deoxy- (HHb) haemoglobin during cycling exercise were measured over the two prefrontal cortices and the right parietal lobe from a 15-probe layout using a continuous-wave NIRS system. Mental demand was significantly higher when performing eccentric compared to concentric cycling (p = .012) and when the intensity was fixed by the torque rather than the perceived effort (p < .001). For both torque- or perceived effort-matched exercises, O2Hb was significantly greater (p < .001) in both prefrontal cortices and right parietal lobe, and HHb decreased in the left and right prefrontal cortices during eccentric compared to concentric cycling. The current study supports that acute eccentric cycling involves a higher mental demand and frontoparietal network activation compared to concentric cycling.