Any exercise, not the combo, may boost older brains

Cognitive decline is one of the biggest worries of ageing, and exercise is one of the few widely promoted tools for slowing it. Aerobic training and resistance training are each recognised as important for preserving and enhancing cognitive function, so many programmes for older adults now combine the two. Whether that combination actually delivers extra cognitive benefit in healthy older people, however, has remained unclear. This review set out to pool the randomised evidence on concurrent aerobic-plus-resistance training and global cognition in adults aged 65 and over.

The authors searched six databases — PubMed, Web of Science, EMBASE, Google Scholar, the Cochrane Library and CNKI — up to July 2024. From 13,533 initial records, they included 12 randomised controlled trials involving 2557 healthy older adults aged 65 or over. Trial quality was rated with the PEDro scale, and results were pooled using a random-effects meta-analysis with heterogeneity quantified by the I² statistic. Crucially, the analysis separated trials by whether the comparison group was active or passive.

Overall, concurrent training had a non-significant effect on global cognition (SMD 0.12, p = 0.200). The subgroup analysis explained why: against passive controls, combined training produced a significant improvement (SMD 0.35, p < 0.001), but against active controls it showed essentially nothing (SMD -0.03, p = 0.80). Heterogeneity was moderate (I² = 49.9%), sensitivity analyses confirmed the results were stable, and no significant publication bias was detected. In short, the combined programme beat inactivity but did not beat other forms of being active.

Aerobic and resistance exercise each have established links to cognitive function, and this analysis complicates the intuitive assumption that stacking them yields extra brain benefit. It suggests the cognitive gains seen in exercise trials may largely reflect being active at all, rather than the specific combination of modalities. The authors call for research into optimal training combinations and sequences to maximise cognitive benefits. Whether particular doses, intensities or orderings of concurrent training could outperform other active options remains an open question.

For a healthy older adult, this is a reason to think that exercising regularly matters more for cognition than finding the perfect mix of training types. Combined aerobic and resistance training did improve global cognition in these trials compared with staying inactive, so it remains a perfectly reasonable way to move. What it did not do was outperform other active conditions, so there is no evidence here that the combination is uniquely brain-protective. The ingredient that mattered in these trials appears to have been movement itself.