High-Intensity Interval Training in Older Adults: a Scoping Review

High-intensity interval training (HIIT) is an increasingly popular form of aerobic exercise which includes bouts of high-intensity exercise interspersed with periods of rest. The health benefits, risks, and optimal design of HIIT are still unclear. Further, most research on HIIT has been done in young and middle-aged adults, and as such, the tolerability and effects in senior populations are less well-known. The purpose of this scoping review was to characterize HIIT research that has been done in older adults including protocols, feasibility, and safety and to identify gaps in the current knowledge. Five databases were searched with variations of the terms, "high-intensity interval training" and "older adults" for experimental or quasi-experimental studies published in or after 2009. Studies were included if they had a treatment group with a mean age of 65 years or older who did HIIT, exclusively. Of 4644 papers identified, 69 met the inclusion criteria. The average duration of training was 7.9 (7.0) weeks (mean [SD]) and protocols ranged widely. The average sample size was 47.0 (65.2) subjects (mean [SD]). Healthy populations were the most studied group (n = 30), followed by subjects with cardiovascular (n = 12) or cardiac disease (n = 9), metabolic dysfunction (n = 8), and others (n = 10). The most common primary outcomes included changes in cardiorespiratory fitness (such as VO2peak) as well as feasibility and safety of the protocols as measured by the number of participant dropouts, adverse events, and compliance rate. HIIT protocols were diverse but were generally well-tolerated and may confer many health advantages to older adults. Larger studies and more research in clinical populations most representative of older adults are needed to further evaluate the clinical effects of HIIT in these groups.

The Benefits of High-Intensity Interval Training on Cognition and Blood Pressure in Older Adults With Hypertension and Subjective Cognitive Decline: Results From the Heart & Mind Study

Background: The impact of exercise on cognition in older adults with hypertension and subjective cognitive decline (SCD) is unclear.

Objectives: We determined the influence of high-intensity interval training (HIIT) combined with mind-motor training on cognition and systolic blood pressure (BP) in older adults with hypertension and SCD.

Methods: We randomized 128 community-dwelling older adults [age mean (SD): 71.1 (6.7), 47.7% females] with history of hypertension and SCD to either HIIT or a moderate-intensity continuous training (MCT) group. Both groups received 15 min of mind-motor training followed by 45 min of either HIIT or MCT. Participants exercised in total 60 min/day, 3 days/week for 6 months. We assessed changes in global cognitive functioning (GCF), Trail-Making Test (TMT), systolic and diastolic BP, and cardiorespiratory fitness.

Results: Participants in both groups improved diastolic BP [F_{(1, 87.32)} = 4.392, p = 0.039], with greatest effect within the HIIT group [estimated mean change (95% CI): −2.64 mmHg, (−4.79 to −0.48), p = 0.017], but no between-group differences were noted (p = 0.17). Both groups also improved cardiorespiratory fitness [F_{(1, 69)} = 34.795, p < 0.001], and TMT A [F_{(1, 81.51)} = 26.871, p < 0.001] and B [F_{(1, 79.49)} = 23.107, p < 0.001]. There were, however, no within- or between-group differences in GCF and systolic BP at follow-up.

Conclusion: Despite improvements in cardiorespiratory fitness, exercise of high- or moderate-intensity, combined with mind-motor training, did not improve GCF or systolic BP in individuals with hypertension and SCD.

Clinical Trial Registration:ClinicalTrials.gov (NCT03545958).

Reshaping the path of vascular cognitive impairment with resistance training: a study protocol for a randomized controlled trial

Background

Subcortical ischemic vascular cognitive impairment (SIVCI) is the most common form of vascular cognitive impairment. Importantly, SIVCI is considered the most treatable form of cognitive impairment in older adults, due to its modifiable risk factors such as hypertension, diabetes mellitus, and hypercholesterolemia. Exercise training is a promising intervention to delay the progression of SIVCI, as it actively targets these cardiometabolic risk factors. Despite the demonstrated benefits of resistance training on cognitive function and emerging evidence suggesting resistance training may reduce the progression of white matter hyperintensities (WMHs), research on SIVCI has predominantly focused on the use of aerobic exercise. Thus, the primary aim of this proof-of-concept randomized controlled trial is to investigate the efficacy of a 12-month, twice-weekly progressive resistance training program on cognitive function and WMH progression in adults with SIVCI. We will also assess the efficiency of the intervention.

Methods

Eighty-eight community-dwelling adults, aged > 55 years, with SIVCI from metropolitan Vancouver will be recruited to participate in this study. SIVCI will be determined by the presence of cognitive impairment (Montreal Cognitive Assessment < 26) and cerebral small vessel disease using computed tomography or magnetic resonance imaging. Participants will be randomly allocated to a twice-weekly exercise program of (1) progressive resistance training or (2) balance and tone training (i.e., active control). The primary outcomes are cognitive function measured by the Alzheimer’s Disease Assessment Scale-Cognitive-Plus (ADAS-Cog-13 with additional cognitive tests) and WMH progression.

Discussion

The burden of SIVCI is immense, and to our knowledge, this will be the first study to quantify the effect of progressive resistance training on cognitive function and WMH progression among adults with SIVCI. Slowing the rate of cognitive decline and WMH progression could preserve functional independence and quality of life. This could lead to reduced health care costs and avoidance of early institutional care.

Trial registration

ClinicalTrials.gov NCT02669394. Registered on February 1, 2016

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05156-1.

A Scoping Review of Multiple-modality Exercise and Cognition in Older Adults: Limitations and Future Directions

The effects of multiple-modality exercise (MME) on brain health warrants further elucidation. Our objectives were to report and discuss the current evidence regarding the influence of MME on cognition and neuroimaging outcomes in older adults without dementia. We searched the literature for studies investigating the effects of MME on measures of cognition, brain structure, and function in individuals 55 years or older without dementia. We include 33 eligible studies. Our findings suggested that MME improved global cognition, executive functioning, processing speed, and memory. MME also improved white and gray matter and hippocampal volumes. These findings were evident largely when compared with no-treatment control groups but not when compared with active (e.g., health education) or competing treatment groups (e.g., cognitive training). MME may improve brain health in older adults without dementia; however, because of possible confounding factors, more research is warranted.

Memory Function and Brain Functional Connectivity Adaptations Following Multiple-Modality Exercise and Mind-Motor Training in Older Adults at Risk of Dementia: An Exploratory Sub-Study

Background

Multiple-modality exercise improves brain function. However, whether task-based brain functional connectivity (FC) following exercise suggests adaptations in preferential brain regions is unclear. The objective of this study was to explore memory function and task-related FC changes following multiple-modality exercise and mind-motor training in older adults with subjective cognitive complaints.

Methods

We performed secondary analysis of memory function data in older adults [n = 127, mean age 67.5 (7.3) years, 71% women] randomized to an exercise intervention comprised of 45 min of multiple-modality exercise with additional 15 min of mind-motor training (M4 group, n = 63) or an active control group (M2 group, n = 64). In total, both groups exercised for 60 min/day, 3 days/week, for 24 weeks. We then conducted exploratory analyses of functional magnetic resonance imaging (fMRI) data collected from a sample of participants from the M4 group [n = 9, mean age 67.8 (8.8) years, 8 women] who completed baseline and follow-up task-based fMRI assessment. Four computer-based memory tasks from the Cambridge Brain Sciences cognitive battery (i.e. Monkey Ladder, Spatial Span, Digit Span, Paired Associates) were employed, and participants underwent 5 min of continuous fMRI data collection while completing the tasks. Behavioral data were analyzed using linear mixed models for repeated measures and paired-samples t-test. All fMRI data were analyzed using group-level independent component analysis and dual regression procedures, correcting for voxel-wise comparisons.

Results

Our findings indicated that the M4 group showed greater improvements in the Paired Associates tasks compared to the M2 group at 24 weeks [mean difference: 0.47, 95% confidence interval (CI): 0.08 to 0.86, p = 0.019]. For our fMRI analysis, dual regression revealed significant decrease in FC co-activation in the right precentral/postcentral gyri after the exercise program during the Spatial Span task (corrected p = 0.008), although there was no change in the behavioral task performance. Only trends for changes in FC were found for the other tasks (all corrected p < 0.09). In addition, for the Paired Associates task, there was a trend for increased co-activation in the right temporal lobe (Brodmann Area = 38, corrected p = 0.07), and left middle frontal temporal gyrus (corrected p = 0.06). Post hoc analysis exploring voxel FC within each group spatial map confirmed FC activation trends observed from dual regression.

Conclusion

Our findings suggest that multiple modality exercise with mind-motor training resulted in greater improvements in memory compared to an active control group. There were divergent FC adaptations including significant decreased co-activation in the precentral/postcentral gyri during the Spatial Span task. Borderline significant changes during the Paired Associates tasks in FC provided insight into the potential of our intervention to promote improvements in visuospatial memory and impart FC adaptations in brain regions relevant to Alzheimer's disease risk.

Clinical Trial Registration

The trial was registered in ClinicalTrials.gov in April 2014, Identifier: NCT02136368.

Heart failure management insights from primary care physicians and allied health care providers in Southwestern Ontario

BACKGROUND

It remains to be determined whether collaborative strategies to improve and sustain overall health in patients with heart failure (HF) are currently being adopted by health care professionals. We surveyed primary care physicians, nurses and allied health care professionals in Southwestern Ontario regarding how they currently manage HF patients and how they perceive limitations, barriers and challenges in achieving optimal management in these patients.

METHODS

We developed an online survey based on field expertise and a review of pertinent literature in HF management. We analyzed quantitative data collected via an online questionnaire powered by Qualtrics®. The survey included 87 items, including multiple choice and free text questions. We collected participant demographic and educational background, and information relating to general clinical practice and specific to HF management. The survey was 25 min long and was administered in October and November of 2018.

RESULTS

We included 118 health care professionals from network lists of affiliated physicians and clinics of the department of Family Medicine at Western University; 88.1% (n = 104) were physicians while 11.9% (n = 14) were identified as other health care professionals. Two-thirds of our respondents were females (n = 72) and nearly one-third were males (n = 38). The survey included mostly family physicians (n = 74) and family medicine residents (n = 25). Most respondents indicated co-managing their HF patients with other health care professionals, including cardiologists and internists. The vast majority of respondents reported preferring to manage their HF patients as part of a team rather than alone. As well, the majority respondents (n = 47) indicated being satisfied with the way they currently manage their HF patients; however, some indicated that practice set up and communication resources, followed by experience and education relating to HF guidelines, current drug therapy and medical management were important barriers to optimal management of HF patients.

CONCLUSIONS

Most respondents indicated HF management was satisfactory, however, a minority did identify some areas for improvement (communication systems, work more collaborative as a team, education resources and access to specialists). Future research should consider these factors in developing strategies to enhance primary care involvement in co-management of HF patients, within collaborative and multidisciplinary systems of care.

The Impact of Blood Pressure Dipping Status on Cognition, Mobility, and Cardiovascular Health in Older Adults Following an Exercise Program

Objectives: To determine whether a dual-task gait and aerobic exercise intervention differentially impacted older adults with normal blood pressure (BP) dipping status (dippers) compared to those with nondipping status (nondippers). Methods: This study was a secondary analysis involving participants (mean age = 70.3 years, 61% women) who attended a laboratory-based exercise intervention over a 6-month period (40 min/day and 3 days/week). Participants were assessed in measures of cognition, mobility, and cardiovascular health at baseline, 3, 6, and 12 months (after a 6-month no-contact follow-up). Results: We observed improvements in cognition in both groups at 6 and 12 months, although no between-group differences were seen. Nondippers demonstrated superior improvements in usual gait velocity and step length after the exercise intervention compared to dippers. Dippers reduced daytime systolic BP at 6 and 12 months to a greater extent than nondippers. Discussion: BP dipping status at baseline did not influence exercise benefits to cognition but did mediate changes in mobility and cardiovascular health.

Multiple-modality exercise and mind-motor training to improve mobility in older adults: A randomized controlled trial

OBJECTIVE

To investigate the effects of multiple-modality exercise with or without additional mind-motor training on mobility outcomes in older adults with subjective cognitive complaints.

METHODS

This was a 24-week randomized controlled trial with a 28-week no-contact follow-up. Community-dwelling older adults underwent a thrice -weekly, Multiple-Modality exercise and Mind-Motor (M4) training or Multiple-Modality (M2) exercise with an active control intervention (balance, range of motion and breathing exercises). Study outcomes included differences between groups at 24weeks and after the no-contact follow-up (i.e., 52weeks) in usual and dual-task (DT, i.e., serial sevens [S7] and phonemic verbal fluency [VF] tasks) gait velocity, step length and cycle time variability, as well as DT cognitive accuracy.

RESULTS

127 participants (mean age 67.5 [7.3] years, 71% women) were randomized to either M2 (n=64) or M4 (n=63) groups. Participants were assessed at baseline, intervention endpoint (24weeks), and study endpoint (52weeks). At 24weeks, the M2 group demonstrated greater improvements in usual gait velocity, usual step length, and DT gait velocity (VF) compared to the M4 group, and no between- or within-group changes in DT accuracy were observed. At 52weeks, the M2 group retained the gains in gait velocity and step length, whereas the M4 group demonstrated trends for improvement (p=0.052) in DT cognitive accuracy (VF).

CONCLUSIONS

Our results suggest that additional mind-motor training was not effective to improve mobility outcomes. In fact, participants in the active control group experienced greater benefits as a result of the intervention.

Combined Dual-Task Gait Training and Aerobic Exercise to Improve Cognition, Mobility, and Vascular Health in Community-Dwelling Older Adults at Risk for Future Cognitive Decline1

This 6-month experimental case series study investigated the effects of a dual-task gait training and aerobic exercise intervention on cognition, mobility, and cardiovascular health in community-dwelling older adults without dementia. Participants exercised 40 min/day, 3 days/week for 26 weeks on a Biodex GaitTrainer2 treadmill. Participants were assessed at baseline (V0), interim (V1: 12-weeks), intervention endpoint (V2: 26-weeks), and study endpoint (V3: 52-weeks). The study outcomes included: cognition [executive function (EF), processing speed, verbal fluency, and memory]; mobility: usual & dual-task gait (speed, step length, and stride time variability); and vascular health: ambulatory blood pressure, carotid arterial compliance, and intima-media thickness (cIMT). Fifty-six participants [age: 70(6) years; 61% female] were included in this study. Significant improvements following the exercise program (V2) were observed in cognition: EF (p = 0.002), processing speed (p < 0.001), verbal fluency [digit symbol coding (p < 0.001), phonemic verbal fluency (p < 0.001)], and memory [immediate recall (p < 0.001) and delayed recall (p < 0.001)]; mobility: usual & dual-task gait speed (p = 0.002 and p < 0.001, respectively) and step length (p = 0.001 and p = 0.003, respectively); and vascular health: cIMT (p = 0.002). No changes were seen in the remaining outcomes. In conclusion, 26 weeks of dual-task gait training and aerobic exercise improved performance on a number of cognitive outcomes, while increasing usual & dual-task gait speed and step length in a sample of older adults without dementia.