The Rise (and Fall) of Decision-Making During Increasing Physical Exercise

The relationship between acute physical exercise and decision-making remains debated. Various evidence leans towards an inverted U-shaped curve where decision-making peaks during moderate acute physical exertion and deteriorates under heavy exercise. This study examined behavioural and computational markers of decision-making during a conflict task across three increasing cycling intensities, up to the heavy domain. Thirty-one participants completed the Eriksen Flanker task at light, moderate, and heavy exercise intensities. Throughout the experiment, heart rate, oxygen uptake, and rates of perceived exertion were measured and confirmed the prescribed exercise intensities. Results indicated that reaction times decreased, while accuracy remained stable. Diffusion Model for Conflict (DMC) analyses showed that drift rate followed the hypothesised inverted U-shaped pattern, peaking at moderate intensity, suggesting optimal evidence accumulation at this workload. Decision boundaries decreased linearly with intensity, indicating less cautious responding under higher exertion. This partially supports arousal-based models such as the Yerkes-Dodson law, highlighting moderate intensity as a potential “sweet spot” for decision-making. The integration of computational modelling provides novel insight into the interplay between intensity levels of acute exercise and cognitive processes. This has implications for sports performance, training strategies, and high-stakes professions requiring rapid decisions under physical stress.