Exercising regularly would not have as many advantages for a good cognition as had been thought until now, according to a new study carried out by Spanish scientists from the University of Granada (UGR), belonging to the Mind, Brain and Behavior Research Center (CIMCYC), which suggests that there is not enough scientific evidence to show that the physical exercise benefits cognitive function, and that its impact would be negligible. The surprising results of it are published today in the scientific journal Nature Human Behaviour.
Luis Ciriaa CIMCYC researcher and member of the ‘Human Brain and Cognition’ group, and his collaborators have analyzed 24 meta-analyses and 109 primary studies on this topic, in which a total of 11,266 healthy people of all ages have participated, and have shown that the initial positive effects of physical exercise on cognition (which were small and statistically significant) disappeared across all ages and cognitive functions when other potentially influencing factors—such as study baselines and differences between studies—were taken into account. control groups, a fundamental aspect of intervention designs to control for methodological problems such as the placebo effect, and corrected for the publication bias.
The effects of exercise on cognition would have been exaggerated
In the article, the authors highlight that the scientific literature on effects of exercise on cognitive functions has grown exponentially and has been based on exaggerated messages, without taking into account conflicting findings and contrary opinions, noting that in most meta-analyses there are important methodological weaknesses, so their results do not necessarily represent the true effect of the evidence accumulated over time.
The benefits of physical exercise, especially with regard to physical health, are sufficient in themselves to justify public health policies that promote the regular practice of sport.
They stress, however, that this does not mean that physical exercise cannot have positive effects on cognitive functioning, nor that it can be detrimental to cognition, but that it is necessary to be cautious when establishing a causal relationship between the practice of physical exercise and cognition because strong causal evidence is not available at this time.
Thus, although the World Health Organization (WHO) recommends regular exercise as a measure to maintain good cognitive health in both children and the elderly, according to the new UGR study, this recommendation would not be supported by the available scientific evidence. currently.
However, the benefits of physical exerciseespecially with regard to physical health, are sufficient in themselves to justify public health policies that promote the regular practice of sport as a healthy habit, without having to appeal to the supposed effects at a cognitive level, the UGR researchers conclude .
Eef Hogervorst, Professor of Psychology at Loughborough University (United Kingdom), has given her opinion on this new study in statements to SMC Spain: “The findings of this study are unexpected, since the current literature reveals a strong link between exercise and cognition, which can be supported by the results of most of the meta-analyses included in the review (22 of 24). In addition, previous studies have reported that the exercise reduces the risk of dementia characterized by the cognitive decline. Therefore, accurate interpretation of the results is very important for clinical and public health implications.”
“Although a small part of the large heterogeneity is reported to be reduced by key moderators, a moderate heterogeneity of 57% of unknown origin makes it difficult to obtain conclusive results. The different types of exercise, the wide age range, and the different outcome measures might be the reasons for avoiding a strong showing that physical exercises have a small positive effect on cognition. Furthermore, some methodological limitations of the study should not be overlooked. The fact that the search strategy is not comprehensive enough, that specific exercise types are not used as keywords and that some large databases such as CENTRAL, CINAHL and Embase are not included may make it questionable whether they were included. all eligible meta-analyses in the literature. Another important point is that the methodological qualities of both the included reviews and the primary randomized controlled trials included in the meta-analysis were not mentioned and the results were not interpreted accordingly.
“I appreciate that the authors consider the results from different perspectives. However, clearer information on the intensity, type, and duration of the included workouts would have further clarified the reasons for these unexpected results. In conclusion, the article offers a vision that invites the reflection on the efficacy of physical exercise in cognition. It is important to point out that the results must be interpreted with caution due to the methodological limitations of the study”, concludes this expert.
Fuente: University of Granada (UGR)