EFFECTIVENESS OF HIGH-INTENSITY EXERCISE VERSUS MIND-BODY INTERVENTIONS IN IMPROVING COGNITION IN OLDER ADULTS WITH MILD COGNITIVE IMPAIRMENT: A SYSTEMATIC REVIEW AND META-ANALYSIS

EFECTIVIDAD DEL EJERCICIO DE ALTA INTENSIDAD FRENTE A INTERVENCIONES MENTE-CUERPO EN LA MEJORA DE LA COGNICIÓN EN ADULTOS MAYORES CON DETERIORO COGNITIVO LEVE: REVISIÓN SISTEMÁTICA Y METAANÁLISIS

Introduction

The changes associated with aging tend to affect a wide variety of tissues, organs, systems, and their functions due to physiological variations, genetic predispositions, prior illnesses, and lifestyle-related factors, among others. These changes interfere with an individual’s ability to perform activities of daily living (Minaker, 2012). Part of this normal aging process may manifest as cognitive impairment, which can appear in a mild form or progress toward dementia (Jongsiriyanyong & Limpawattana, 2018). This impairment affects memory and other cognitive skills, impacting the individual’s independence and quality of life (WHO, 2023).

Recently, the Alzheimer’s Association (2024b) reported that approximately 12%–18% of people aged 60 years or older live with Mild Cognitive Impairment (MCI), of whom 10%–15% will develop dementia each year, and one-third of this population will develop Alzheimer’s disease within five years. These figures raise public health concerns, as according to the WHO (2022), the number of people over 60 years old has surpassed that of children under five, and this population is projected to double between 2015 and 2050, increasing from 12% to 22%. Although pharmacological treatments currently exist to address symptoms associated with MCI or dementia, non-pharmacological interventions such as Physical Activity (PA) or Exercise (EX) are also recommended, since physically inactive individuals are at greater risk of experiencing cognitive and motor decline (Alzheimer’s Association, 2024a; Lövdén et al., 2013; Nyberg et al., 2014).

These types of interventions not only help maintain or improve cognitive function but also significantly contribute to health, quality of life, and the ability to perform daily activities (Alzheimer’s Association, 2024a). In particular, Mind-Body Exercises (MBE), which are low-intensity practices such as tai chi, mindfulness, and qigong, promote mental relaxation, concentration, and breathing control, and may improve cognitive performance in older adults with MCI (Cai et al., 2023). On the other hand, High-Intensity Functional Training (HIFT), which combines aerobic and strength exercises through functional, multi-joint movements performed at high intensities (Feito et al., 2018), has also been shown to reduce the risk of cognitive decline (Rivas-Campo et al., 2022).

In this systematic review, a comparison was made between two types of exercises—Mind-Body Exercises (MBE) and High-Intensity Training—regarding their effects on cognitive performance. In this sense, it is essential to determine which type of exercise yields better results in preventing conditions caused by MCI or dementia, in order to make appropriate recommendations according to individual needs.

Materials and Methods

The present systematic review and meta-analysis aimed to compare the effects of high-intensity exercise and Mind-Body Exercises (MBE) on cognitive performance in older adults with Mild Cognitive Impairment (MCI) or dementia. The review was conducted in accordance with the guidelines outlined in the PRISMA 2020 Statement and the Cochrane Handbook for Systematic Reviews of Interventions.

Inclusion Criteria

The articles included in this review met the following inclusion criteria: i) studies that used high-intensity exercise and MBE as part of the treatment for older adults with MCI or dementia in the experimental group; ii) randomized controlled trials (RCTs); and iii) objective measures of cognition before and after the exercise intervention. These criteria ensured that the selected studies focused on interventions involving high-intensity exercise and MBE, employed rigorous experimental designs, and used objective measures to evaluate changes in cognition before and after the interventions.

Exclusion Criteria

The following exclusion criteria were applied: studies that did not measure the relevant variables of interest; studies focusing on ethnic minorities, populations with limited mobility, acute infections, neurological diseases, or hormonal disorders; and studies involving participants with a history of psychiatric disorders. Publications such as books, meta-analyses, reviews, systematic reviews, protocols, clinical trial registrations, and non-peer-reviewed articles were also excluded. These criteria ensured that only methodologically rigorous and relevant studies were included.

Information Sources

A bibliographic search was conducted between January and April 2024 in the following databases: PubMed, Scopus, Web of Science, and CINAHL.

Search Strategy

The following search strategy was used with relevant keywords:

("high-intensity training" OR "high-intensity exercise" OR "HIIT" OR "High-Intensity exercise training" OR "high intensity training" OR "high intensity exercise" OR "HIT" OR "High Intensity exercise training" OR "resistance training" OR "Physical exercise" OR "intensive training program" OR "circuit training" OR "dance" OR "high-intensity" OR "Pilates" OR "Yoga" OR "Tai Chi" OR "Core-Based" OR "Mind-Body") AND ("older adults with cognitive impairment" OR "cognitive impairment" OR "Cognitive decline" OR "Dementia") AND ("global cognition" OR "Cognition" OR "cognitive function" OR "Fall risk" OR "functionality").

Study Selection Process

The search results were processed using the Rayyan QCRI application (Ouzzani et al., 2016) (https://rayyan.qcri.org/welcome), where duplicates were automatically removed. Two authors (J.A.G.S. and S.Z.G.) independently and blindly screened titles and abstracts to verify compliance with inclusion criteria and conducted full-text reviews. Any discrepancies were resolved by consensus with a third author (L.M.V.B.).

Data Extraction

The primary variables of this review focused on outcomes related to cognition. Each included article was classified based on its year of publication, country, authors, participant characteristics (age, sample size, and group distribution), interventions applied to the experimental and control groups (intervention duration, session length and frequency, and intensity level), type of variable, test used, and follow-up period.

Assessment of Methodological Quality

The methodological quality of the selected articles was evaluated using the PEDro scale, one of the most widely used tools for assessing methodological quality. Scores were obtained from the official PEDro website when available. When not available, two authors (J.A.G.S. and S.Z.G.) independently evaluated the studies, and discrepancies were resolved by a third author (L.M.V.B.). The first item, which assesses external validity, was excluded from the final score. The remaining items were scored as 1 (present) or 0 (absent). Items 2 through 11 were considered for the total score, resulting in a possible range of 0 to 10 points. Scores between 0–3 were rated as Poor, 4–5 as Fair, 6–8 as Good, and >9 as Excellent.

Analytical Decisions for the Meta-Analysis

Heterogeneity among studies was assessed using Cochran’s Q test and quantified using the I² statistic with a 95% confidence interval. Heterogeneity was categorized as low (<25%), moderate (25%–75%), or high (>75%) (Higgins et al., 2003). Fixed-effect or random-effects models were applied depending on the observed heterogeneity and variability. To evaluate potential publication bias, funnel plots were used, and asymmetry was tested using Egger’s method, considering a p-value < 0.05 as statistically significant. The meta-analysis was conducted using the Comprehensive Meta-Analysis V4 software.

Results

Study Selection Process

The initial search across the selected databases yielded a total of 2,439 articles. After the removal of duplicates, 1,607 unique records remained. These records underwent title and abstract screening, resulting in 106 articles selected for full-text review. Following this stage, 28 studies met the inclusion criteria and were ultimately included in this systematic review and meta-analysis (Abbas et al., 2022; Ayari et al., 2023; Bossers et al., 2015; Chen et al., 2023; Cheng et al., 2014; de Oliveira Silva et al., 2019; Fiatarone Singh et al., 2014; Hoffmann et al., 2016; Huang et al., 2019; Jiayuan et al., 2022; Jin et al., 2020; Lam et al., 2012; Lamb et al., 2018; Liu-Ambrose et al., 2016; Maffei et al., 2017; Moon et al., 2020; Nascimento et al., 2014; Rivas-Campo et al., 2023; Sanders et al., 2020; Telenius et al., 2015a, 2015b; Toots et al., 2017; Xu et al., 2023; Yoon et al., 2017; Young, 2020; Yu et al., 2022; Zhu et al., 2018, 2022). Figure 1 illustrates the PRISMA flow diagram representing the systematic review process, detailing the number of records identified, screened, assessed for eligibility, and included in the final quantitative synthesis.

Methodological Quality

The methodological quality of the included studies was assessed using the PEDro scale, as this tool is one of the most appropriate for evaluating clinical trials involving exercise interventions. A total of 25 studies were evaluated using the official PEDro database, while only two studies (Ayari et al., 2023; Nascimento et al., 2014) were assessed manually. Overall, the 28 studies included in this review demonstrated good methodological quality. However, it is important to note that none of the studies blinded participants or therapists (items 5 and 6 of the PEDro scale). Furthermore, twelve studies (Ayari et al., 2023; Bossers et al., 2015; Cheng et al., 2014; de Oliveira Silva et al., 2019; Hoffmann et al., 2016; Lam et al., 2012; Maffei et al., 2017; Nascimento et al., 2014; Rivas-Campo et al., 2023; Sanders et al., 2020; Yoon et al., 2017; Young, 2020) did not implement concealed allocation of participants into groups (item 3). Table 1 summarizes the methodological quality scores of the included studies according to the PEDro scale.

Studies Characteristics

All the articles included in this systematic review were randomized controlled clinical trials. The studies were published in various countries, including Switzerland (Ayari et al., 2023; Jiayuan et al., 2022; Jin et al., 2020; Rivas-Campo et al., 2023; Xu et al., 2023; Zhu et al., 2022), the Netherlands (Cheng et al., 2014; Hoffmann et al., 2016; Huang et al., 2019; Toots et al., 2017), England (Bossers et al., 2015; Lamb et al., 2018; Maffei et al., 2017; Moon et al., 2020; Sanders et al., 2020; Telenius et al., 2015b; Young, 2020; Yu et al., 2022), Japan (Yoon et al., 2017), New Zealand (Zhu et al., 2018), the United States (Abbas et al., 2022; Chen et al., 2023; Fiatarone Singh et al., 2014; Lam et al., 2012; Liu-Ambrose et al., 2016; Telenius et al., 2015a), Ireland (de Oliveira Silva et al., 2019), and the United Arab Emirates (Nascimento et al., 2014).

However, it is important to note that while the articles were published in these countries, the actual research was conducted in different locations, such as China (Chen et al., 2023; Cheng et al., 2014; Huang et al., 2019; Jin et al., 2020; Lam et al., 2012; Young, 2020; Yu et al., 2022; Zhu et al., 2018, 2022), Denmark (Hoffmann et al., 2016), the Netherlands (Bossers et al., 2015; Sanders et al., 2020), France (Ayari et al., 2023), Sweden (Toots et al., 2017), Korea (Yoon et al., 2017), the United States (Moon et al., 2020; Xu et al., 2023), Brazil (de Oliveira Silva et al., 2019; Nascimento et al., 2014), Colombia (Rivas-Campo et al., 2023), Lebanon (Abbas et al., 2022), Australia (Fiatarone Singh et al., 2014), Canada (Liu-Ambrose et al., 2016), Italy (Maffei et al., 2017), Norway (Telenius et al., 2015a, 2015b), and the United Kingdom (Lamb et al., 2018).

The studies were conducted between 2012 and 2024, with 2022 and 2023 being the years with the highest number of publications (Abbas et al., 2022; Ayari et al., 2023; Chen et al., 2023; Jiayuan et al., 2022; Rivas-Campo et al., 2023; Xu et al., 2023; Yu et al., 2022; Zhu et al., 2022).

From the 1,607 studies initially identified, 28 were included in this review. These studies employed a variety of high-intensity exercise and mind-body intervention protocols, all focusing on the measurement of cognition as the primary variable. A total of 2,923 older adults participated across the included studies, with 1,396 assigned to the control groups and 1,537 receiving exercise interventions.

Intervention

The studies included in this systematic review with meta-analysis evaluated the effectiveness of mind-body interventions and high-intensity exercises on global cognition in older adults with cognitive impairment. The studies implementing mind-body interventions were based on practices such as Qigong, Mahjong, Tai Chi, Baduanjin, and Mindfulness. These interventions were generally performed twice per week (Jiayuan et al., 2022; Jin et al., 2020; Moon et al., 2020; Young, 2020) or three times per week, with only one study conducting a single session per week (Yu et al., 2022); additionally, one study combined two individual home sessions with one group session each week (Moon et al., 2020).

In general, each session lasted 60 minutes (Chen et al., 2023; Cheng et al., 2014; Jiayuan et al., 2022; Jin et al., 2020; Xu et al., 2023; Young, 2020; Yu et al., 2022), although interventions lasting 20 minutes (Huang et al., 2019; Moon et al., 2020) and 30 minutes (Lam et al., 2012) were also reported. Most studies indicated that the intervention period lasted 3 months (Cheng et al., 2014; Moon et al., 2020; Xu et al., 2023) or 6 months (Chen et al., 2023; Jiayuan et al., 2022; Yu et al., 2022), while three studies reported durations of 7 weeks (Young, 2020), 10 months (Huang et al., 2019), and 12 months (Lam et al., 2012).

Among the articles implementing high-intensity training, seven studies based their interventions on moderate-to-high-intensity aerobic exercise (Ayari et al., 2023; Bossers et al., 2015; Hoffmann et al., 2016; Liu-Ambrose et al., 2016; Maffei et al., 2017; Zhu et al., 2018, 2022), five studies performed High-Intensity Functional Exercise (HIFE) (Abbas et al., 2022; Rivas-Campo et al., 2023; Telenius et al., 2015a, 2015b; Toots et al., 2017), and three studies implemented combined interventions (Abbas et al., 2022; Karssemeijer et al., 2019; Lamb et al., 2018). Additionally, interventions involving multimodal training (de Oliveira Silva et al., 2019), progressive resistance training (Fiatarone Singh et al., 2014), and Low-Speed Strength Training (LSST) (Yoon et al., 2017) were reported.

The frequency of high-intensity interventions was three sessions per week (Abbas et al., 2022; Fiatarone Singh et al., 2014; Hoffmann et al., 2016; Liu-Ambrose et al., 2016; Maffei et al., 2017; Nascimento et al., 2014; Rivas-Campo et al., 2023; Sanders et al., 2020; Zhu et al., 2018, 2022) or two sessions per week (Bossers et al., 2015; de Oliveira Silva et al., 2019; Lamb et al., 2018; Telenius et al., 2015b, 2015a; Yoon et al., 2017), with only two studies reporting one session per week (Ayari et al., 2023) and one study reporting five sessions every two weeks (Toots et al., 2017). The average session duration was 60 minutes (Ayari et al., 2023; de Oliveira Silva et al., 2019; Fiatarone Singh et al., 2014; Hoffmann et al., 2016; Lamb et al., 2018; Liu-Ambrose et al., 2016; Maffei et al., 2017; Nascimento et al., 2014; Telenius et al., 2015b, 2015a; Yoon et al., 2017), although some studies reported 30–35-minute sessions (Bossers et al., 2015; Sanders et al., 2020; Zhu et al., 2018, 2022) and 45-minute sessions (Rivas-Campo et al., 2023; Toots et al., 2017).

Most studies reported an intervention period of 3 months (Abbas et al., 2022; de Oliveira Silva et al., 2019; Rivas-Campo et al., 2023; Sanders et al., 2020; Telenius et al., 2015a; Yoon et al., 2017; Zhu et al., 2018, 2022), while other durations included 4 months (Ayari et al., 2023), 6 months (Fiatarone Singh et al., 2014; Liu-Ambrose et al., 2016; Telenius et al., 2015b), and 7 months (Maffei et al., 2017; Toots et al., 2017).

Global Cognition

The main variable in this review was global cognition, for which the studies implemented the following assessment tools: the Montreal Cognitive Assessment (MoCA) (Abbas et al., 2022; Chen et al., 2023; Jin et al., 2020; Nascimento et al., 2014; Xu et al., 2023; Yoon et al., 2017; Yu et al., 2022; Zhu et al., 2018), the Mini-Mental State Examination (MMSE) (Abbas et al., 2022; Ayari et al., 2023; Bossers et al., 2015; Cheng et al., 2014; de Oliveira Silva et al., 2019; Hoffmann et al., 2016; Huang et al., 2019; Jiayuan et al., 2022; Lam et al., 2012; Rivas-Campo et al., 2023; Sanders et al., 2020; Telenius et al., 2015a, 2015b; Toots et al., 2017; Yoon et al., 2017; Young, 2020; Zhu et al., 2022), and the Alzheimer’s Disease Assessment Scale–Cognitive Subscale (ADAS-Cog) (Fiatarone Singh et al., 2014; Lamb et al., 2018; Liu-Ambrose et al., 2016; Maffei et al., 2017).

Among the included studies, ten reported statistically significant improvements in global cognition among participants who received mind-body exercise interventions such as Qigong, Mahjong, Tai Chi, Baduanjin, and Mindfulness (Chen et al., 2023; Cheng et al., 2014; Jiayuan et al., 2022; Jin et al., 2020; Lam et al., 2012; Moon et al., 2020; Xu et al., 2023; Young, 2020; Yu et al., 2022). Additionally, of the studies implementing high-intensity exercise interventions, fourteen (Ayari et al., 2023; Bossers et al., 2015; de Oliveira Silva et al., 2019; Fiatarone Singh et al., 2014; Hoffmann et al., 2016; Liu-Ambrose et al., 2016; Maffei et al., 2017; Nascimento et al., 2014; Rivas-Campo et al., 2023; Telenius et al., 2015a, 2015b; Yoon et al., 2017; Zhu et al., 2018, 2022) reported statistically significant improvements in cognition, identifying positive effects on global cognition, executive function, and memory. Only four studies (Abbas et al., 2022; Lamb et al., 2018; Sanders et al., 2020; Toots et al., 2017) found that this type of intervention did not result in cognitive improvements.

Meta-Analysis

For this meta-analysis, a subgroup analysis was conducted using the type of intervention—either high-intensity exercise or mind-body exercise—as the grouping variable. The mean effect size was calculated using Hedges’ g for each subgroup. For high-intensity exercise, fifteen studies were included, showing a moderate and statistically significant mean effect size on cognition (g = 0.644, 95% CI: 0.185–1.104, p = 0.006), favoring the groups of older adults with mild cognitive impairment who received the intervention (Figure 2).

On the other hand, in the subgroup analysis for mind-body interventions, nine studies were included, showing a small but statistically significant mean effect size on cognition (g = 0.404, 95% CI: 0.288–0.521, p < 0.001), favoring the groups of older adults with mild cognitive impairment who received the intervention (Figure 3).

Discussion

The objective of this systematic review and meta-analysis was to determine which type of intervention—high-intensity exercise or mind-body interventions—produces greater effects on global cognition in older adults with mild cognitive impairment (MCI). The most relevant findings indicated that, although both types of interventions are beneficial, high-intensity exercise shows a greater effect on cognition (g = 0.644, 95% CI: 0.185–1.104, p = 0.006) compared with mind-body interventions (g = 0.404, 95% CI: 0.288–0.521, p < 0.001), suggesting that more intense physical activities may have a stronger impact on preserving and improving cognitive functions in this population.

This review included 28 randomized controlled trials, most of which demonstrated good methodological quality, while only two studies showed poor methodological quality (de Oliveira Silva et al., 2019; Yoon et al., 2017). Although the overall methodological quality was good, it is important to note that none of the trials were able to blind participants or therapists, which could lead to an overestimation of the results by 7% to 13% (Savović et al., 2012). This is a common challenge in exercise-based intervention studies, where blinding participants is almost impossible due to the nature of the intervention itself.

Following the meta-analysis, it was determined that high-intensity exercise has a moderate and statistically significant effect size (g = 0.644, p = 0.006) on cognition in older adults with MCI. This may be due to the fact that this type of intervention increases levels of brain-derived neurotrophic factor (BDNF), a key protein involved in neurogenesis and synaptic plasticity, which strengthens neuronal connections and enhances higher mental functions (Erickson et al., 2013). This increase in BDNF, along with other physiological mechanisms such as improved cerebral vascularization and reduced oxidative stress, could explain why high-intensity exercise is effective in preserving and even improving cognition in older adults (Cotman & Berchtold, 2002).

On the other hand, mind-body interventions showed a small but statistically significant mean effect size (g = 0.404, p < 0.001). These interventions, which include practices such as yoga and tai chi, may reduce cortisol levels and improve the regulation of the hypothalamic–pituitary–adrenal axis, leading to a better stress response and contributing to less cognitive decline (Pascoe et al., 2017). Additionally, literature suggests that these interventions enhance hippocampal volume and stimulate the frontal lobes, leading to the activation of microglial cells, which facilitate waste clearance and promote overall brain health (Chen et al., 2023).

When comparing high-intensity exercise with mind-body interventions, the former appears to be more effective in improving cognition. This finding aligns with the results reported by Northey et al. (2018) in their systematic review, which identified greater cognitive benefits in older adults following high-intensity interventions. The physical and mental demands of high-intensity exercise seem to more efficiently activate the neural networks associated with cognition, positioning it as the preferred option for enhancing cognitive performance in this population (Northey et al., 2018). Similarly, this difference may be explained by the lower capacity of low-intensity interventions to induce robust neuroplastic changes. Reviews such as those by Sofi et al. (2011) and Smith et al. (2010) reflect a similar pattern, emphasizing once again that higher-intensity interventions tend to provide greater cognitive benefits when compared with lower-intensity or mind-control-based exercises.

This review has multiple strengths and limitations that are important to consider when interpreting the findings. On the one hand, it included a considerable number of studies for each type of intervention, and the risk of publication bias was low. Regarding the limitations, none of the studies blinded participants or therapists, which could lead to overestimated effects. Additionally, although studies were conducted in various regions worldwide, a geographical bias was evident, which may limit the generalizability of the findings—particularly to countries in Latin America and Africa. Finally, the high heterogeneity in the intervention protocols makes it difficult to establish a specific model, highlighting the need for further research focused on the dose–response relationship of these interventions.

Conclusions

This systematic review and meta-analysis demonstrate that both high-intensity exercise and mind-body exercises (MBE) can improve cognition in older adults with mild cognitive impairment (MCI). However, high-intensity training (HIT) appears to have a greater effect on the preservation and enhancement of cognitive functions in this population. These findings should be interpreted with caution due to potential biases resulting from the high heterogeneity of the included studies, the geographical locations where they were conducted, and the lack of blinding of participants or therapists. Nevertheless, the incorporation of high-intensity exercise into the comprehensive care plan for older adults may represent an effective strategy to improve cognition.

Ethics Committee Statement

Not applicable, as this study is a secondary review of existing information.

Conflict of Interest Statement

The authors declare that there is no conflict of interest.

Funding

This research was funded by the Fundación Universitaria del Área Andina and the Antonio José Camacho University Institution through the research project CV2024-M3-P-13290.

Authors' Contribution

Conceptualization: D.F.A.-R. & S.Z.-G.; Methodology: D.F.A.-R. & J.A.G.S.; Formal Analysis: D.F.A.-R. & S.Z.-G.; Writing – Original Draft: S.Z.-G., J.A.G.S. & L.M.V.B.; Writing – Review & Editing: D.F.A.-R. & C.M.B.-C.; Supervision: D.F.A.-R.; Project Administration: D.F.A.-R.; Funding Acquisition: D.F.A.-R. All authors have read and agreed to the published version of the manuscript.

Data Availability Statement

Data are available upon request from the corresponding author at dafanador4@areandina.edu.co

References

Author notes

Autor para la correspondencia: Diego Fernando Afanador-Restrepo, dafanador4@areandina.edu.co

Additional information

Título Abreviado: High-Intensity Exercise vs. Mind-Body Interventions for Cognition in Older Adults

How to cite this article: Afanador-Restrepo, D.F., Zapata-Gil, S., García, J.A., Valencia, L.M., & Basto-Cardona, C.M. (2024). Effectiveness of High-Intensity Exercise versus Mind-Body Interventions in Improving Cognition in Older Adults with Mild Cognitive Impairment: Systematic Review and Meta-Analysis. Cultura, Ciencia y Deporte, 20(66), 2335. https://doi.org/10.12800/ccd.v20i66.2335