Aerobic and resistance exercise acutely increase cognitive performance (CP). High-intensity functional training (HIFT) combines the characteristics of both regimes but its effect on CP is unclear. Thirty-five healthy individuals (26.7 ± 3.6 years, 18 females) were randomly allocated to three groups. The first (HIFT) performed a functional whole-body workout at maximal effort and in circuit format, while a second walked at 60% of the heart rate reserve (WALK). The third group remained physically inactive reading a book (CON). Before and after the 15-min intervention period, CP was assessed with the Stroop Test, Trail Making Test and Digit Span Test. Repeated-measures ANOVAs and post-hoc 95% confidence intervals (95% CI) were used to detect time/group differences. A significant group*time interaction was found for the backwards condition of the Digit Span Test (p = 0.04) and according to the 95% CI, HIFT was superior to WALK and CON. Analysis of the sum score of the Digit Span Test and the incongruent condition of the Stroop Test, furthermore, revealed main effects for time (p < 0.05) with HIFT being the only intervention improving CP. No differences were found for the Trail Making Test (p > 0.05). In conclusion, HIFT represents an appropriate method to acutely improve working memory, potentially being superior to moderate aerobic-type exercise. Regular engagement in physical activity is linked to a variety of health benefits. Besides lowering the risk for cardiovascular diseases 1 , it can reduce all-cause mortality up to 33% 2,3. In recent decades, it has also been shown that physical activity may prevent the development of neurodegenerative pathologies 4. Although the mechanisms of this observation are yet to be elucidated, there is accumulating evidence revealing how particularly exercise, a planned and structured subset of physical activity performed at increased energy expenditure 5 , seems to induce both acute and chronic adaptations in the brain. Long-term endurance training of animals evoked angiogenesis, neurogenesis and enhanced synaptic plasticity 6-8. Studies examining humans found expression of the brainderived neurotrophic factor (BDNF) and increases in hippocampal volume occurred following several weeks of aerobic exercise 9. After single endurance training bouts, substantial neurophysiological (e.g. increased delta, theta, alpha and beta detected by electromyography) and neurochemical (e.g. BDNF, insulin-like growth factor 1, dopamine, norepinephrine or serotonin) changes have been observed 10. In view of the strong and multifaceted response of the nervous system to exercise training, research has increasingly attempted to identify its impact on cognitive performance (CP), which can be subdivided in higher-(e.g. inhibitory control or working memory) and lower-order (e.g. attention or reaction time) functions. Available systematic reviews have mostly investigated the effects of aerobic-type exercise, detecting a positive effect on CP even when performed as a single training bout 11-13. Interestingly...