Effects and mechanisms of exercise timing on cognitive function in older type 2 diabetes mellitus patients with mild cognitive impairment: A magnetic resonance imaging-based randomized controlled trial protocol.
This protocol describes a randomized controlled trial that will test whether morning or evening exercise best improves cognitive function in older adults with type 2 diabetes and mild cognitive impairment, using multimodal MRI to investigate mechanisms; no results are reported yet.
Key Findings
Background
The paper is a trial protocol and reports no outcome data; it sets out a plan to identify the optimal time of day for exercise to maximize cognitive benefits in older patients with T2DM-MCI.
The study aims to determine the most effective exercise timing and to investigate the underlying neurobiological mechanisms using multimodal magnetic resonance imaging.
The abstract states that an optimal time of day for exercise to mitigate this neurodegenerative trajectory 'has not been determined'.
The research is expected to provide 'time-specific' evidence for exercise prescription to maximize neurocognitive benefits and mitigate dementia risk.
Methods
The trial will randomize patients aged 60-75 years with T2DM-MCI into three arms: morning exercise, evening exercise, or health education.
Morning exercise group: 09:00-10:10.
Evening exercise group: 19:00-20:10.
Control: a health education group receiving a 12-week health education program.
Methods
The exercise intervention is a 12-week, home-based, remotely supervised program combining aerobic and resistance exercises.
Both exercise groups will complete the same type of program, differing only in time of day.
Each session is scheduled in a roughly 70-minute window (e.g., 09:00-10:10 or 19:00-20:10).
The health education group follows a 12-week program rather than exercise.
Methods
Cognitive function will be assessed at baseline and post-intervention with a battery of six neuropsychological tests.
Tests: Montreal Cognitive Assessment, Color-Word Stroop Test, N-back task, Trail Making Test, Attention Network Test, and Digit Symbol Substitution Test.
Assessments occur at two time points: baseline and post-intervention.
Methods
Secondary measures include imaging-based brain structure and function, blood biomarkers, and physical fitness.
Multimodal MRI will be used to examine neurobiological mechanisms.
Blood biomarkers and physical fitness will also be assessed.
Methods
The study will test whether glycemic control mediates the relationship between exercise and cognitive improvement.
This mediation analysis is motivated by the vicious cycle in which cognitive impairment impairs self-care and worsens glycemic control, further driving cognitive decline.
Exercise is recognized as improving both glycemic control and cognitive function.
Methods
The trial is registered in the Chinese Clinical Trial Registry.
Identifier: ChiCTR2300073737.
What This Means
This paper describes the plan for a clinical trial rather than reporting results. Many older adults with type 2 diabetes also develop mild cognitive impairment, which can make it harder to manage their diabetes and lead to further cognitive decline. Exercise is known to help both blood sugar control and thinking skills, but it is not known whether the time of day matters.
The researchers plan to enroll people aged 60-75 with both conditions and assign them to morning exercise (9:00-10:10), evening exercise (19:00-20:10), or a health education program. The exercise groups will do 12 weeks of home-based, remotely supervised aerobic and resistance exercise. Before and after, participants will take several thinking and attention tests, and will have brain MRI scans, blood tests, and physical fitness assessments. The team will also examine whether improved blood sugar control explains any cognitive benefits.
Because no data have been collected or analyzed in this paper, it cannot say whether morning or evening exercise is better. This research may eventually provide evidence on when to exercise to get the most brain benefit in this population, but that remains to be determined by the completed trial.
Check Your Own Numbers
Upload your bloodwork. We'll cross-reference your results against this study and 4,700 others.
Lin Y, Ma Z, Zhang J, Zhuang J. (2026). Effects and mechanisms of exercise timing on cognitive function in older type 2 diabetes mellitus patients with mild cognitive impairment: A magnetic resonance imaging-based randomized controlled trial protocol.. PloS one. https://doi.org/10.1371/journal.pone.0361868