Comparison of High-Intensity Interval Training to Moderate-Intensity Continuous Training in Older Adults: A Systematic Review

Effects of High-Intensity Interval Training on the Parameters Related to Physical Fitness and Health of Older Adults: A Systematic Review and Meta-Analysis

BACKGROUND

As a novel and time-efficient exercise form, high-intensity interval training (HIIT) has shown great potential in improving health-related physical fitness among diverse populations. However, empirical evidence on its efficacy among the elderly has not been well summarized. This systematic review and meta-analysis aimed to determine the effect of HIIT interventions on the parameters related to physical fitness and health of older adults, including resting heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), cardiorespiratory fitness (CRF), body mass index (BMI), body fat percent (BF%), waist circumference (WC), muscular endurance (ME), muscular strength (MS), muscular power (MP), balance and flexibility, compared to non-exercise and other-exercise (e.g., moderate-intensity continuous training, resistance training) conditions.

METHODS

Literature published from January 2000 to May 2023 was collected through extensive searches across eight databases and relevant review papers. Randomized controlled trials (RCTs) featuring a minimum 2-week exercise intervention for older adults (≥ 60 years) were included. The pooled effect size of Hedges'g was estimated using random-effects models in R. Meta-regression was performed for both categorical (health status, duration of training programme, and frequency) and continuous moderators (mean age, male rate, and attrition rate).

RESULTS

Forty-four eligible RCTs with 1863 participants (52.1% female; 60.5-81.2 years) were included in the quantitative analysis. Compared to non-exercise condition, HIIT significantly improved resting HR (g = -0.36, 95%CI = [-0.67, -0.05], P = 0.032), SBP (g = -0.29, 95%CI = [-0.54, -0.03], P = 0.008), CRF (g = 0.77, 95%CI = [0.51, 1.04], P < 0.001), BF% (g = -0.26, 95%CI = [-0.41, -0.11], P = 0.006), MS (g = 0.47, 95%CI = [0.23, 0.71], P = 0.004), ME (g = 0.65, 95%CI = [0.10, 1.19], P = 0.036), and balance (e.g., timed-up-and-go) (g = -0.79, 95%CI = [-1.19, -0.40], P = 0.035). Compared to other-exercise condition, HIIT significantly improved resting HR (g = -0.11, 95%CI = [-0.21, -0.01], P = 0.029), SBP (g = -0.14, 95%CI = [-0.28, -0.01], P = 0.038), and CRF (g = 0.23, 95%CI = [0.07, 0.38], P = 0.008). No significant difference was found between HIIT and non-exercise condition for DBP, BMI and WC, as well as between HIIT and other-exercise condition for DBP, BMI, BF%, WC, ME, and balance (all P > 0.05). Meta-regression indicated that mean age moderated the HIIT effect on resting HR (b = -0.02, P = 0.014; HIIT vs. other-exercise condition) and SBP (b = 0.03, P = 0.048; HIIT vs. non-exercise), and attrition rate moderated the effect on CRF (b = 0.03, P = 0.007; HIIT vs. non-exercise).

CONCLUSION

This study supports the efficacy of HIIT in improving resting HR, SBP, CRF, BF%, MS, ME and balance among older adults. More empirical evidence is needed to determine the efficacy of HIIT for MP and flexibility in this population.

TRIAL REGISTRATION

PROSPERO CRD42022316246.

A Practice Guide for Physical Therapists Prescribing Physical Exercise for Older Adults

INTRODUCTION

Physical activity and exercise are protective factors for physical and cognitive decline in older adults, but recent studies reveal that a large percentage of this population do not practice exercise at the levels recommended by international guidelines. The frequency, intensity, type, time, volume, and progression (FITT-VP) principles are a widely used method for prescribing physical exercise, allowing the development of a personalized exercise program that meets the needs of each individual.

OBJECTIVES

This masterclass is intended to serve as a professional application tool for physical therapists who prescribe physical exercise for older adults. We present a section for each FITT-VP principle to facilitate handling these principles individually when prescribing exercise for this population.

METHODS

Review of the scientific literature and international guidelines on the prescription of physical exercises for older adults.

RESULTS

Aerobic, mobility, resistance, balance, and flexibility exercises, as well as functional training, should be included in an exercise program for older adults, which should be progressed using different methods for each of the exercise modalities.

CONCLUSIONS

An exercise program for older adults should integrate different exercise modalities. Exercise progression should be performed following the FITT-VP principles and some specific progression factors recommended for each exercise modality.

SIGNIFICANCE

Considering the challenge faced by clinicians in designing a viable exercise program for older adults that responds to international recommendations, with this masterclass we hope to help physical therapists to plan an exercise program that is feasible and at the same time, responds to the expected needs of this population.

Effects of High-Intensity Interval Training on Muscle Strength for the Prevention and Treatment of Sarcopenia in Older Adults: A Systematic Review of the Literature

Sarcopenia is a significant health concern primarily affecting old adult individuals, characterized by age-related muscle loss, and decreased strength, power, and endurance. It has profound negative effects on overall health and quality of life, including reduced independence, mobility, and daily activity performance, osteoporosis, increased fall and fracture risks, metabolic issues, and chronic diseases like diabetes and cardiovascular conditions. Preventive strategies typically involve a combination of proper nutrition and regular physical activity. Among strength training exercises, high-intensity interval training (HIIT) stands out as the most effective approach for improving muscle function in older adults with sarcopenia. The current review identifies and summarizes the studies that have examined the effects of HIIT on muscle strength in older adults as an element of the prevention and treatment of sarcopenia. A systematic search using several computerized databases, namely, MEDLINE/PubMed, Scopus, SPORTDiscus, and Web of Science, was performed on 12 January 2023, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A total of 224 studies were initially retrieved. A total of five studies met the selection criteria. HIIT training shows improvements in body composition and functional and cardiorespiratory capacity, has benefits on muscle strength, increases muscle quality and architecture, and is associated with muscle hypertrophy in healthy older adults. Nonetheless, given the shortcomings affecting primary research in terms of the limited number of studies and the high risk of bias, further research is warranted.

Home-based high-intensity interval training for people with Parkinson's: Protocol for the HIIT-Home4Parkinson's randomized, controlled feasibility study

Background

High-intensity interval training (HIIT) is feasible and beneficial for some people with Parkinson's (PwP), although adherence to extended programs may be problematic. PwP face barriers to exercise such as lack of time, expense, and difficulty with travel logistics due to motor symptoms. HIIT based in the home setting if practical, could therefore be apposite for PwP by overcoming these barriers. However, until now, no home-based HIIT program for PwP has been developed. Cocreated by PwP, clinicians, and family members, the HIIT-Home4Parkinson's (HH4P) program is an innovative, 12-week home-based HIIT program for PwP. This protocol describes a feasibility study designed to assess the feasibility and safety of the HH4P program, explore outcomes that may be sensitive to change, and inform the implementation of a potential full trial.

Methods/design

Using a randomized controlled parallel group design, 24 independently mobile people with Parkinson's of mild to moderate disease severity will be randomized 1:1 to either the HH4P program plus usual care, or usual care alone. Both groups will be assessed at baseline, and upon the completion of the program. Outcomes will include feasibility and safety factors such as recruitment, completion, adverse events, and intervention fidelity with qualitative evaluation along with mechanistic, physiological, and clinical outcomes.

Discussion

Results of this study will inform the rationale and methodological considerations for a full trial with long-term follow-up. Ultimately, further establishing the practicality and utility of home-based HIIT could provide an important exercise option for PwP, potentially leading to extended participation and increased health and well-being for this population.

Hepatoprotective effects of moderate-intensity interval training along with ginger juice in an old male rat model

Aging is a natural process coupled with oxidative stress and chronic inflammation, gradually associated with losing organ function over time. Therefore, the objective of the current work was to peruse the protective effects of 8-week moderate-intensity interval training (MIIT) and ginger extract supplementation on some biomarkers of oxidative stress, inflammation, and lipid metabolism in the liver of elderly males Wistar rats (animal study with ethical code IR.BMSU.REC.1401.015). A total of thirty-two 22-month-aged male Wistar rats were randomly assigned to four groups: (1) control, (2) MIIT, (3) ginger, and (4) MIIT + ginger. After 8 weeks of treadmill training and ginger extract supplementation, the biochemical parameters (liver enzyme and lipid profile), inflammatory mediators (leucine-rich α-2 glycoprotein 1 (LRG1), tumor necrosis factor-alpha, and interleukin-6), pro-oxidant (malondialdehyde), antioxidant biomarkers (catalase, superoxide dismutase, total antioxidant capacity), some lipid metabolism regulators (carnitine palmitoyltransferase 1, adipose triglyceride lipase, acetyl-CoA carboxylase, CD36, and AMP-activated protein kinase), and liver histopathological changes were appraised. The acquired findings pointed out that MIIT combined with ginger extract appreciably diminished the serum levels of LRG1, liver enzymes, and lipid profile relative to the other groups after 8 weeks of intervention. Furthermore, ginger + MIIT caused a great improvement in the liver levels of antioxidant biomarkers, pro-oxidant, pro-inflammatory biomarkers, lipid metabolism regulators, and liver tissue impairment compared to the other groups. The findings suggested that MIIT + ginger was more effective in improving examined indices relative to the other groups.

The feasibility, safety, physiological and clinical effects of high-intensity interval training for people with Parkinson's: a systematic review and meta-analysis

BACKGROUND

Exercise is important for people with Parkinson's (PwP), with high-intensity interval training (HIIT) proposed as a feasible and effective exercise modality. However, no literature synthesis for PwP has been undertaken.

OBJECTIVES

To evaluate the feasibility, safety, physiological and clinical effects of HIIT for PwP.

METHODS

Systematic searches of Medline, Embase, CINAHL, Web of Science, and Google Scholar were undertaken. Studies that included ≥ 2 weeks of HIIT for PwP and reported sufficient detail for full quality assessment were eligible. Quality was assessed with the TESTEX scale or the Downs and Black tool according to study design. Feasibility and safety data, physiological and clinical outcomes were extracted. Meta-analyses explored the pooled effects of HIIT on VO_2peak/max compared to moderate-intensity continuous exercise (MICE) and usual care.

RESULTS

Eleven articles were identified (seven controlled/comparator studies and four single group) including 117 HIIT participants predominantly of mild-to-moderate disease severity. HIIT programmes were professionally supervised and between 6 weeks and 24 months. Overall, study quality was deemed to be moderate to good. Following screening, nine studies reported 90-100% programme completion; however, only one was > 12 weeks in duration. Adverse events were uncommon. HIIT improved VO_2peak/max compared to usual care, but not to MICE. Increased brain-derived neurotrophic factor (BDNF) and improved motor symptoms were also reported.

CONCLUSION

Up to 12 weeks of supervised HIIT appears to be feasible and safe for some people with mild-to-moderate disease severity. HIIT improves cardiorespiratory fitness and may increase BDNF and improve motor symptoms in PwP. Future studies should explore safe ways to facilitate access and long-term adherence.

VascuFit: vascular effects of non-linear periodized exercise training in sedentary adults with elevated cardiovascular risk - protocol for a randomized controlled trial

Background

Early vascular aging (EVA) is increasingly prevalent in the general population. Exercise is important for primary cardiovascular prevention, but often insufficient due to ineffective training methods and a lack of biomarkers suitable to monitor its vascular effects. VascuFit will assess the effectiveness of non-linear periodized aerobic exercise (NLPE) in a non-athletic sedentary population to improve both established and promising biomarkers of EVA.

Methods

Forty-three sedentary adults, aged 40–60 years, with elevated cardiovascular risk will either engage in 8 weeks of ergometer-based NLPE (n = 28) or receive standard exercise recommendations (n = 15). The primary outcome will be the change of brachial-arterial flow-mediated dilation (baFMD) after versus before the intervention. Secondary outcomes will be the change in static vessel analysis (SVA; clinical biomarker of microvascular endothelial function), endomiRs (microRNAs regulating key molecular pathways of endothelial cell homeostasis) and circulating cellular markers of endothelial function (mature endothelial cells, endothelial progenitor cells). Tertiary outcomes will be the change in sphingolipidome, maximum oxygen capacity, and traditional cardiovascular risk factors (blood pressure, triglycerides, cholesterol, fasting glucose, high-sensitivity C-reactive protein).

Discussion

We expect an improvement of baFMD of at least 2.6% and significant pre-post intervention differences of SVA and endomiRs as well as of the tertiary outcomes in the intervention group. VascuFit may demonstrate the effectiveness of NLPE to improve endothelial function, thus vascular health, in the general sedentary population. Furthermore, this project might demonstrate the potential of selected molecular and cellular biomarkers to monitor endothelial adaptations to aerobic exercise.

Trial registration

The trial was registered on www.clinicaltrials.gov (NCT05235958) in February 11^th 2022.

Association Between Device-Measured Physical Activity and Incident Heart Failure: A Prospective Cohort Study of 94 739 UK Biobank Participants

BACKGROUND

Studies of objectively measured physical activity (PA) have investigated acute cardiovascular outcomes but not heart failure (HF), an emerging chronic condition. This study aimed to investigate the dose-response relationship between device-measured PA and HF by intensity of PA.

METHODS

This was a prospective cohort study of 94 739 UK Biobank participants who had device-measured PA in 2013 to 2015 and were free from myocardial infarction and HF. PA was measured with a wrist-worn accelerometer, and time spent on light-, moderate-, and vigorous-intensity PA was extracted. Incident HF was ascertained from linked hospital and death records. Cox proportional hazard models with cubic penalized splines were used to study the associations, which were adjusted for sociodemographic and lifestyle factors. Competing risk was handled with cause-specific hazard ratios.

RESULTS

The overall incidence of HF was 98.5 per 10 000 person-years over a median 6.1 years of follow-up. Compared with participants who undertook no moderate- to vigorous-intensity PA, those who performed 150 to 300 min/wk of moderate-intensity PA (hazard ratio, 0.37 [95% CI, 0.34-0.41]) and 75 to 150 min/wk of vigorous-intensity PA (hazard ratio, 0.34 [95% CI, 0.25-0.46]) were at lower HF risk. The association between vigorous-intensity PA and HF was reverse-J shaped with a potentially lower risk reduction above 150 min/wk.

CONCLUSIONS

Device-measured PA, especially moderate-intensity PA, was associated with a lower risk of HF. Current vigorous-intensity PA recommendations should be encouraged but not increased. In contrast, increasing moderate-intensity PA may be beneficial even among those meeting current recommendations.

Device-measured physical activity and incident affective disorders

BACKGROUND

Studies on physical activity (PA) and mental health are largely limited to self-reported PA. This study aims to use prospective cohort data to investigate the association between device-measured PA and affective disorders.

METHODS

A total of 37,327 participants from UK Biobank who had not had any prior affective disorder diagnoses were included in this prospective cohort study. Wrist-worn accelerometers were used to measure total, light (LPA), moderate (MPA), and vigorous (VPA) PA. Associations between PA domains and affective disorders were analysed using penalised splines in Cox proportional hazard models. Analyses were adjusted for other intensity-specific PA and sociodemographic and lifestyle factors. Sensitivity analyses were conducted adjusting for body mass index and longstanding illnesses as well as excluding events in the first 2 years of follow-up. Preventable fractions for the population were estimated for MPA and VPA.

RESULTS

Over a median follow-up of 6.8 years, 1262 (3.4%) individuals were diagnosed with affective disorders. Replacing 30 min of sedentary behaviour in a week with MPA (HR 0.95, 95% CI 0.94-0.97) or VPA (HR 0.91, 95% CI 0.85-0.98) was associated with lower risk of affective behaviours, up to 500 and 120 min of MPA and VPA. Assuming causality, 5.14% and 18.88% of affective disorders could have been prevented if MPA ≥150 min/week and VPA ≥75 min/week were achieved, respectively, across the study population.

CONCLUSIONS

Device-measured MPA and VPA were associated with lower risk of affective disorders. The potential mental health benefits of MPA continue to accrue above the current World Health Organization recommendation.

The role of resistance exercise training for improving cardiorespiratory fitness in healthy older adults: a systematic review and meta-analysis

BACKGROUND

Declines in cardiorespiratory fitness (CRF) and muscle mass are both associated with advancing age and each of these declines is associated with worse health outcomes. Resistance exercise training (RET) has previously been shown to improve muscle mass and function in the older population. If RET is also able to improve CRF, as it has been shown to do in younger populations, it has the potential to improve multiple health outcomes in the expanding older population.

METHODS

This systematic review aimed to identify the role of RET for improving CRF in healthy older adults. A search across CINAHL, MEDLINE, EMBASE and EMCARE databases was conducted with meta-analysis performed on eligible papers to identify improvements in established CRF parameters (VO2 peak, aerobic threshold (AT), 6-minute walking distance test (6MWT) following RET intervention. Main eligibility criteria included older adults (aged over 60), healthy cohorts (disease-specific cohorts were excluded) and RET intervention.

RESULTS

Thirty-seven eligible studies were identified. Meta-analysis revealed a significant improvement in VO2 peak (MD 1.89 ml/kg/min; 95% confidence interval (CI) 1.21-2.57 ml/kg/min), AT (MD 1.27 ml/kg/min; 95% CI 0.44-2.09 ml/kg/min) and 6MWT (MD 30.89; 95% CI 26.7-35.08) in RET interventions less than 24 weeks. There was no difference in VO2 peak or 6MWT in interventions longer than 24 weeks.

DISCUSSION

This systematic review adds to a growing body of evidence supporting the implementation of RET in the older population for improving whole-body health, particularly in time-limited timeframes.

Description and Functional Benefits of Meeting Frequency, Intensity, and Time of Resistance and Cardiovascular Exercises: A Study of Older Adults in a Community-Based, Slow-Stream Rehabilitation, Hospital-to-Home Transition Program

This prospective cohort study described cardiovascular and resistance exercises completed by older adults in a community-based, slow-stream rehabilitation, hospital-to-home transition program; compared exercises completed to the American College of Sports Medicine (ACSM) exercise guidelines; and, assessed differences in Late Life Function and Disability Index (LLFDI)-Function Component (FC) between older adults who met and did not meet the ACSM guidelines. Descriptive statistics and Factorial ANCOVA were conducted. For cardiovascular exercise 59.3% of participants met frequency, 73.4% met intensity, and 35.9% met time. For resistance exercise, 67.2% of participants met frequency, 42.2% met intensity, and 76.6% number of repetitions. Participants who met both frequency and time for cardiovascular exercise had higher LLFDI-FC scores, as did those who met intensity and/or number of repetitions for resistance exercise. The findings provide support that older adults engaged in a slow-stream rehabilitation program can meet the ACSM exercise guidelines for community-dwelling older adults, and that meeting the guidelines improves function.

The Effects of High-Intensity Interval Training (HIIT) on Fall Risk Factors in Healthy Older Adults: A Systematic Review

High-intensity interval training (HIIT) improves functional capacity, muscle power and physical performance in older adults with and without comorbidities. The aim of this study was to explore the effectiveness of HIIT as a method for reducing major fall risk factors (balance, muscle strength and physical activity) in older adults. A systematic literature search was conducted following the PRISMA guidelines. A computerized search was conducted using electronic databases (PubMed, CINAHL, Cochrane Library, APA PsycInfo, Web of Science, Scopus, PEDro, and AgeLine) published up to July 2021. Eleven papers (9 studies) of moderate quality (mean of 5.5 in Pedro scale) involving 328 healthy older adults met the inclusion criteria. Studies were characterized by high heterogeneity in terms of methodology, HIIT modality and protocol, subject characteristics, and outcome measures. Results indicate that HIIT cannot be recommended as a single modality for fall prevention in older adults due to insufficient data and no consensus among the studies. HIIT appears to be a safe and well-tolerated supplement to proven fall prevention programs, due to its effects on lower limb strength reflected in functional performance tests, and on dynamic balance and subjective balance perception. However, caution is warranted following HIIT, especially after the first session, due to possible temporary instability.

Effects of Three Different Exercise Strategies for Optimizing Aerobic Capacity and Skeletal Muscle Performance in Older Adults: A Pilot Study

This Brief Report describes a pilot study of the effect of 12 weeks of stationary bicycle high-intensity interval training, stationary bicycle moderate-intensity continuous training, and resistance training on cardiorespiratory, muscular, and physical function measures in insufficiently-active older adults (N=14; 66.4±3.9 years; 3 male, 11 female). After baseline testing, participants were randomly assigned to one of the exercise groups. High-intensity interval training and moderate-intensity continuous training had small-to-large effect sizes on cardiorespiratory/endurance and physical function measures, but very small effect sizes on muscular measures. Resistance training had small-to-large effect sizes on cardiorespiratory, muscular, and physical function measures. This pilot study should be interpreted cautiously, but findings suggest that resistance exercise may be the most effective of the three studied exercise strategies for older adults as it can induce beneficial adaptations across multiple domains. These effect sizes can be used to determine optimal sample sizes for future investigations.

High-intensity exercise and cognitive function in cognitively normal older adults: a pilot randomised clinical trial

BACKGROUND

Physical inactivity has been consistently linked to increased risk of cognitive decline; however, studies examining the impact of exercise interventions on cognition have produced inconsistent findings. Some observational studies suggest exercise intensity may be important for inducing cognitive improvements; however, this has yet to be thoroughly examined in older adult cohorts. The objective of the current study was to evaluate the effect of systematically manipulated high-intensity and moderate-intensity exercise interventions on cognition.

METHODS

This multi-arm pilot randomised clinical trial investigated the effects of 6 months of high-intensity exercise and moderate-intensity exercise, compared with an inactive control, on cognition. Outcome measures were assessed at pre- (baseline), post- (6 months), and 12 months post-intervention. Ninety-nine cognitively normal men and women (aged 60-80 years) were enrolled from October 2016 to November 2017. Participants that were allocated to an exercise group (i.e. high-intensity or moderate-intensity) engaged in cycle-based exercise two times per week for 6 months. Cognition was assessed using a comprehensive neuropsychological test battery. Cardiorespiratory fitness was evaluated by a graded exercise test.

RESULTS

There was a dose-dependent effect of exercise intensity on cardiorespiratory fitness, whereby the high-intensity group experienced greater increases in fitness than the moderate-intensity and control groups. However, there was no direct effect of exercise on cognition.

CONCLUSIONS

We did not observe a direct effect of exercise on cognition. Future work in this field should be appropriately designed and powered to examine factors that may contribute to individual variability in response to intervention.

TRIAL REGISTRATION

This study is registered with the Australian New Zealand Clinical Trials Registry (ACTRN12617000643370). Registered on 3 May 2017-retrospectively registered. https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=372780.