Moderate-intensity cycling did not improve cognitive or mood symptoms in older adults with subjective cognitive decline
A randomized controlled trial of 38 community-dwelling older adults (mean age 74.6 years, 69% female) found no significant benefit of 12 weeks of moderate-intensity cycling on cognitive symptoms, depressive or anxiety symptoms, or quality of life compared to a control group.
Researchers conducted a secondary analysis of a randomized controlled trial to test whether moderate-intensity cycling exercise could improve cognitive and affective symptoms—depression and anxiety—as well as quality of life in older adults with subjective cognitive decline (SCD). The study enrolled 38 community-dwelling older adults with SCD, with a mean age of 74.6 years (SD 7.4), of whom 69% were female.
Participants were randomized to either 12 weeks of structured cycling exercise (36 sessions) or a control condition, and outcomes were evaluated using analysis of covariance adjusting for baseline values. The results showed no statistically significant between-group differences across any outcome measure (all p-values ranged from 0.06 to 0.70). While effect sizes for anxiety symptoms favored the control group (between-group change = −5.36 [4.74], ηp² = 0.11), this was not clinically meaningful and the overall pattern suggested the intervention had no clear benefit. The authors note that the study occurred during the COVID-19 pandemic and that the attention and social interaction provided by study participation in an otherwise secluded population may have benefited both groups equally, obscuring a true exercise effect. Larger trials conducted outside of pandemic conditions are needed to clarify whether exercise helps this population.
The lack of significant findings is notable because the sample size was small (n=38) and the study was conducted during COVID-19, when both treatment and control groups may have experienced unusual levels of social isolation and support effects. The effect sizes, while occasionally moderate in magnitude, consistently failed to reach statistical significance and did not show a clear direction favoring exercise. Importantly, subjective cognitive decline is a subtle condition—people report cognitive concerns but testing often shows normal performance—and it is possible that the 12-week duration or cycling-specific modality was insufficient to produce detectable changes in this population. Prior work has shown promise for combined cognitive and aerobic training in at-risk older adults, but this exercise-only intervention did not demonstrate additional benefit over control. The timing during a pandemic when both groups received heightened attention and social contact may have masked any true exercise advantage by equally benefiting both arms.
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Open in Cadence →References
- Exercise Impact on Affective/Cognitive Symptoms and QoL in Subjective Cognitive Decline: An RCT. — American journal of Alzheimer's disease and other dementias (Read the original)