Increased cortisol levels caused by acute resistance physical exercise impair memory and learning ability

Acute physical exercise works as an activator of the responses of the human organism to stress. This is based on the activation of the hypothalamic-pituitary-adrenal (HPA) axis, affecting physical, physiological and psychological levels. This study aimed to analyse the effects of a single bout of high-intensity resistance exercise on cognitive-behavioural responses: visuo-spatial path learning and memory, as well as physiological responses (salivary cortisol levels). Nineteen healthy male military-trained powerlifting subjects were tested in a within-subject design on two experimental days with an interval of 48 h. The stress and cognitive variables were measured by cortisol levels and Ruff-Light trail-learning test (RULIT) test scores, respectively. The results showed the immediate influence of acute exercise on cortisol, with significantly higher cortisol levels found in subjects after completion of the acute resistance exercise. In addition, this study found a significant deterioration of memory and learning ability after a dose of intense resistance exercise. In conclusion, the study highlights the relative effects of resistance exercise on cortisol and cognitive performance depending on the intensity and type of the exercise, the moment of measurement and the cerebral areas implicated.

The acute exercise-cognition interaction: From the catecholamines hypothesis to an interoception model

An interoception model for the acute exercise-cognition interaction is presented. During exercise following the norepinephrine threshold, interoceptive feedback induces increased tonic release of extracellular catecholamines, facilitating phasic release hence better cognitive performance of executive functions. When exercise intensity increases to maximum, the nature of task-induced norepinephrine release from the locus coeruleus is dependent on interaction between motivation, perceived effort costs and perceived availability of resources. This is controlled by interaction between the rostral and dorsolateral prefrontal cortices, orbitofrontal cortex, anterior cingulate cortex and anterior insula cortex. If perceived available resources are sufficient to meet predicted effort costs and reward value is high, tonic release from the locus coeruleus is attenuated thus facilitating phasic release, therefore cognition is not inhibited. However, if perceived available resources are insufficient to meet predicted effort costs or reward value is low, tonic release from the locus coeruleus is induced, attenuating phasic release. As a result, cognition is inhibited, although long-term memory and tasks that require switching to new stimuli-response couplings are probably facilitated.