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

The relationship between acute physical exercise and decision-making remains debated, with evidence leaning towards an inverted U-shaped curve during increasing acute physical exertion. This study examined behavioural and computational markers of decision-making across three increasing cycling intensities during a conflict task. Thirty-one participants completed the Eriksen Flanker task at light, moderate, and heavy exercise intensities. Throughout the experiment, heart rate, oxygen uptake, and lactate concentrations were measured. These physiological measures linearly increased with intensities, confirming our protocol. 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 how intensity levels of acute exercise modulate cognitive processes. This has implications for sports performance, training strategies, and high-stakes professions requiring rapid decisions under physical stress.