Home-based High-intensity Interval Training Research Articles

HIIT at Home: Enhancing Cardiorespiratory Fitness in Older Adults-A Randomized Controlled Trial.

This study aimed to investigate the effectiveness of a 6-month home-based high-intensity interval training (HIIT) intervention to improve peak oxygen consumption (V̇O2peak) and lactate threshold (LT) in older adults. Two hundred thirty-three healthy older adults (60-84 years; 54% females) were randomly assigned to either 6-month, thrice-weekly home-based HIIT (once-weekly circuit training and twice-weekly interval training) or a passive control group. Exercise sessions were monitored using a Polar watch and a logbook for objective and subjective data, respectively, and guided by a personal coach. The outcomes were assessed using a modified Balke protocol combining V̇O2peak and LT measures. General linear regression models assessed between-group differences in change and within-group changes for each outcome. There was a significant between-group difference in the pre-to-post change in V̇O2peak (difference: 1.8 [1.2; 2.3] mL/kg/min; exercise: +1.4 [1.0; 1.7] mL/kg/min [~5%]; control: -0.4 [-0.8; -0.0] mL/kg/min [approximately -1.5%]; effect size [ES]: 0.35). Compared with controls, the exercise group had lower blood lactate concentration (-0.7 [-0.9; -0.4] mmol/L, ES: 0.61), % of peak heart rate (-4.4 [-5.7; -3.0], ES: 0.64), and % of V̇O2peak (-4.5 [-6.1; -2.9], ES: 0.60) at the intensity corresponding to preintervention LT and achieved a higher treadmill stage (% incline) at LT (0.6 [0.3; 0.8]; ES: 0.47), following the intervention. This study highlights the effectiveness of a home-based HIIT intervention as an accessible and equipment-minimal strategy to induce clinically meaningful improvements in cardiorespiratory fitness in older adults. Over 6 months, the exercise group showed larger improvements in all outcomes compared with the control group. Notably, the LT outcome exhibited a more pronounced magnitude of change than V̇O2peak.

Acute and Chronic Endothelial Responses to Home-based High Intensity Interval Training in Healthy Older Adults

Advancing age is associated with endothelial dysfunction, a key early event in atherosclerosis development. Endurance exercise is recommended for cardiovascular disease prevention and some studies report endurance exercise training has beneficial effects on endothelial function in older adults. We have recently developed a supervised home-based exercise intervention using high intensity interval training on an all-extremity non-weight-bearing ergometer (HIIT-ANE). We tested the hypotheses that in healthy older adults: 1) endothelial function is improved in response to chronic HIIT-ANE, 2) the acute endothelial responses to HIIT-ANE are different in the trained and untrained states, and 3) the acute and chronic endothelial responses to HIIT-ANE are related. We assessed flow-mediated dilation (FMD), a measure of endothelial function, using brachial artery ultrasonography in twenty healthy sedentary older adults (age: 66±1, means ± SE; 11 postmenopausal women and 9 men). FMD was assessed: 1) in response to chronic HIIT-ANE (at baseline, after 8 weeks of normal lifestyle (control condition), and after 8 weeks of home-based HIIT-ANE) and 2) in response to a single session of HIIT-ANE (at pre-exercise, end of exercise and 1-hr and 24-hrs post-exercise), in the untrained and trained states. Following 8 weeks of HIIT-ANE, FMD was improved compared with baseline (3.39±0.30 vs. 4.18±0.46 %, P=0.005), but was not significantly changed from pre- to post-HIIT-ANE (3.68±0.44 vs. 4.18±0.46 %, P=0.3) or from baseline to post-control (3.39±0.30 vs. 3.68±0.44 %, P=0.4). In the untrained state, FMD was attenuated in response to a single bout of HIIT-ANE from pre- to 1-hr post-exercise (4.15±0.35 vs. 2.92±0.36 %, P=0.0004) and returned to pre-exercise level in 24-hrs post-exercise (4.15±0.35 vs. 3.98±0.40 %, P=1). In the trained state, the acute FMD response to HIIT-ANE was similar to the untrained state (P=0.6 for training state × time). The chronic change in FMD was inversely related with the acute change in FMD in the trained state (ρ=-0.70; p<0.001), but not in the untrained state (ρ=-0.12; P=0.6). Biological sex did not significantly influence the acute or chronic FMD responses to HIIT-ANE (P≥0.1). In healthy older adults: 1) FMD is improved following 8-weeks of home-based remotely supervised HIIT-ANE compared to baseline, 2) FMD is attenuated and normalized within 24 hours of a single session of HIIT-ANE, and 3) chronic changes in FMD are related to acute changes in FMD. This work was supported by the National Institute of Aging grant AG063143. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Feasibility of remotely supervised home-based high intensity interval training and effects on aerobic fitness and body composition in healthy older adults

Aging is associated with declines in aerobic fitness and increases in adiposity, both of which increase the risk of cardiovascular disease in older adults. High intensity interval training is an effective strategy for cardiovascular disease risk reduction; however, this promising exercise regimen may be inaccessible to older adults due to weight-bearing limitations or inability to travel to a fitness center. To address these barriers, we have developed a remotely supervised, home-based exercise intervention using high intensity interval training on an all-extremity non-weight-bearing ergometer (HIIT-ANE). The purpose of this study was to investigate the hypotheses that remotely supervised home-based HIIT-ANE would be feasible and lead to improvements in aerobic fitness and body composition in healthy older adults. Twenty sedentary older adults free of major clinical disease (66±1 yrs, mean ± SE) participated in this study. HIIT-ANE was remotely delivered at home under supervision via video conferencing (Zoom) and live heart rate monitoring (Zephyr OmniSense, Medtronic). HIIT-ANE consisted of a 10-min warm-up, 4 × 4-min intervals at 90% HRmax interspersed by 3 × 3-min bouts of active recovery at 70% HRmax, and a 5-min cool down and was performed on 4 days/week. Feasibility was assessed throughout the 8 weeks of HIIT-ANE. Aerobic fitness (maximal oxygen consumption) and body composition (dual-energy x-ray absorptiometry) were assessed at baseline and following an 8-week control period of normal lifestyle and an 8-week HIIT-ANE period. We found that exercise compliance to HIIT-ANE — the number of completed sessions relative to the number of scheduled sessions — was 96±1% and there were no adverse events related to the exercise intervention. Aerobic fitness increased in response to HIIT-ANE (baseline vs. post-HIIT-ANE: 23.7±1.2 vs. 27.0±1.1 ml/kg/min, P=0.001; pre- and post-HIIT-ANE: 22.5±1.2 vs. 27.0±1.1 ml/kg/min, P<0.001), but decreased following the control period (23.7±1.2 vs. 22.5±1.2 ml/kg/min, P=0.04). Body fat % (36±2 vs. 35±2%, P=0.001) and fat mass (28.4±2.0 vs. 27.0±2.0 kg, P=0.003) decreased following HIIT-ANE, but fat free mass did not significantly change ( P=0.05 for time effect; 48.5±1.7 vs. 49.3±1.7 kg). Body weight and body mass index did not change throughout the study duration ( P≥0.8 for time effect). In conclusion, remotely supervised home-based HIIT-ANE was feasible and safe and was associated with improved aerobic fitness and body composition in healthy older adults. This work was supported by the National Institute of Aging grant AG063143. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

High-intensity interval training and cardiorespiratory fitness in adults: An umbrella review of systematic reviews and meta-analyses.

High-intensity interval training (HIIT) is characterized by repeated bouts of relatively intense exercise interspersed with recovery periods. Previous studies have evaluated this exercise strategy with various population subgroups, regimens, and comparator groups, limiting the generalizability of findings. We performed a novel umbrella review to generate an up-to-date synthesis of the available evidence regarding the effect of HIIT on cardiorespiratory fitness (CRF) in adults as compared to non-exercise control and traditional continuous forms of exercise such as moderate-intensity continuous training (MICT). An umbrella review was conducted in accordance with the Preferred Reporting Items for Overviews of Reviews guideline. Seven databases (MEDLINE, EMBASE, Cochrane Database, CINAHL, Scopus, SPORTDiscus, and Web of Science) were searched until February 2024. Systematic reviews with meta-analyses comparing HIIT and active/non-active control conditions were included. Literature search, data extraction, and methodological quality assessment (AMSTAR-2) were conducted independently by two reviewers. Twenty-four systematic reviews with meta-analyses, representing 429 primary studies and 12 967 unique participants, met the inclusion criteria. Most of the systematic reviews received moderate-to-critically low AMSTAR-2 scores. The data showed that HIIT, including the particularly intense variant "sprint interval training" (SIT), significantly increases CRF in adults compared to non-exercise control (standardized mean difference [SMD]: 0.28 to 4.31; weighted mean difference [WMD]: 3.25 to 5.5 mL/kg/min) and MICT (SMD: 0.18 to 0.99; WMD: 0.52 to 3.76 mL/kg/min). This effect was consistently observed across specific groups of individuals (e.g., apparently healthy adults, individuals with overweight/obesity, older adults, and high-level athletes) and HIIT modalities (e.g., low-volume HIIT, whole-body HIIT, home-based HIIT, aquatic HIIT, and short SIT). Existing evidence from systematic reviews consistently supports the effect of HIIT on enhancing CRF in adults when compared to non-exercise control and MICT. Our findings offer a comprehensive basis that may potentially contribute to informing physical activity guidelines aimed at improving CRF in the general population.

Home-based high intensity interval training in patients with intermittent claudication: a systematic review protocol

Introduction: The aim of this systematic review is to consider the evidence base for home-based high intensity interval training (HIIT) in patients with intermittent claudication (IC). Prior knowledge of the evidence base suggests that there may be little research considering HIIT in patients with IC. If so, the evidence base across all cardiovascular diseases will be considered. Methods: Medline, EMBASE, CINAHL and Cochrane CENTRAL databases will be searched for terms including ‘peripheral arterial disease’, ‘intermittent claudication’, ‘home-based exercise’, ‘high intensity interval training’ and ‘home-based high intensity interval training’. All prospective randomised trials and non-randomised studies considering home-based HIIT in patients with IC will be included. Studies will not be excluded based on the use of a comparator arm, meaning single-arm studies as well as multi-arm trials will also be included. If appropriate, based on the extant literature, a meta-analysis of randomised controlled trials will be conducted. The outcomes of interest will include intervention components, intervention feasibility (based on uptake and completion rates), intervention tolerability (based on compliance and adherence to the intervention), maximum walking distance, pain-free walking distance, quality of life and cardiorespiratory fitness. Conclusion: This review aims to assess the evidence for home-based HIIT in patients with IC, to establish its feasibility and to inform the refinement of an existing supervised HIIT intervention to allow it to also be delivered remotely. Following this, a pilot randomised controlled trial to compare HIIT versus usual care supervised exercise programmes will be developed. For this, the interventions will be delivered either in person or remotely in real-time, depending on centre availability and patient preference.

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

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. Using a randomized controlled parallel group design, 24independently 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. 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.

Home-based high-intensity interval training improves cardiorespiratory fitness: a systematic review and meta-analysis

BackgroundHigh-intensity interval training (HIIT) is an effective methods to improve maximal oxygen uptake. However, there is no definitive conclusion about the specific effectiveness of home-based HIIT. This review investigated the effects of home-based HIIT on cardiorespiratory fitness in a systematic review and meta-analysis.MethodsFour electronic databases were searched (PubMed, Cochran database, Web of Science, Igaku Chuo Zasshi) for studies through March 25, 2023. Eligibility criteria include randomized controlled trials of home-based HIIT in adult people regardless disease or handicaped. Comparisons were made between non-exercise controls, laboratory-based HIIT, and moderate-intensity continuous training (MICT). The primary outcome was defined as cardiorespiratory fitness and the secondary outcome was defined as patient-reported outcomes. The standardized mean difference (SMD) with 95% confidence intervals (CIs) was calculated for quantitative indices. The random-effect model was used as the pooling method.ResultsTwo hundred seven studies were identified, and 15 satisfied the inclusion criteria. The meta-analysis for cardiorespiratory fitness showed superiority of home-based HIIT to non-exercise controls (SMD 0.61, 95% CI: 0.21, 1.02). However, no significant difference in cardiorespiratory fitness was observed between home-based HIIT and lab-based HIIT (SMD: -0.35, 95%CI: -0.73, 0.03). Also, no significant difference was observed between the home-based HIIT and MICT (SMD 0.34, 95% CI: -0.05, 0.73).ConclusionThese results indicated that home-based HIIT was an effective intervention for improving cardiorespiratory fitness in healthy adults and patients. Importantly, this review found no significant differences in cardiorespiratory fitness between home-based HIIT and the group of laboratory HIIT and MICT, highlighting its comparable effectiveness and potential as a practical and valuable exercise intervention.

A pilot study to assess the feasibility of a remotely monitored high-intensity interval training program prior to allogeneic hematopoietic stem cell transplantation.

Although allogeneic hematopoietic stem cell transplantation (HCT) can be a curative therapy for hematologic disorders, it is associated with treatment-related complications and losses in cardiorespiratory fitness and physical function. High-intensity interval training (HIIT) may be a practical way to rapidly improve cardiorespiratory fitness and physical function in the weeks prior to HCT. The primary aim of this study was to assess the feasibility of implementing a pre-HCT home-based HIIT intervention. The secondary aim was to evaluate pre to post changes in cardiorespiratory fitness and physical function following the intervention. This was a single-arm pilot study with patients who were scheduled to undergo allogeneic HCT within six months. Patients were instructed to complete three 30-minute home-based HIIT sessions/week between the time of study enrollment and sign-off for HCT. Sessions consisted of a 5-minute warm-up, 10 high and low intervals performed for one minute each, and a 5-minute cool-down. Prescribed target heart rates (HR) for the high- and low-intensity intervals were 80-90% and 50-60% of HR reserve, respectively. Heart rates during HIIT were captured via an Apple Watch and were remotely monitored. Feasibility was assessed via retention, session adherence, and adherence to prescribed interval number and intensities. Paired t-tests were used to compare changes in fitness (VO2peak) and physical function [Short Physical Performance Battery (SPPB), 30-second sit to stand, and six-minute walk test (6MWT)] between baseline and sign-off. Pearson correlations were used to determine the relationship between intervention length and changes in cardiorespiratory fitness or functional measures. Thirteen patients (58.8±11.6 years) participated in the study, and nine (69.2%) recorded their training sessions throughout the study. Median session adherence for those nine participants was 100% (IQR: 87-107). Adherence to intervals was 92% and participants met or exceeded prescribed high-intensity HR on 68.8±34.8% of intervals. VO2peak improved from baseline to sign-off (14.6±3.1 mL/kg/min to 17.9±3.3 mL/kg/min; p<0.001). 30-second sit to stand and SPPB chair stand scores significantly improved in adherent participants. Improvements in 30-second sit to stand (13.8±1.5 to 18.3±3.3 seconds) and 6MWT (514.4±43.2 to 564.6±19.3) exceeded minimal clinically important improvements established in other chronic disease populations, representing the minimum improvement considered meaningful to patients. Findings demonstrate that implementing a pre-HCT home-based remotely monitored HIIT program is feasible and may provide benefits to cardiorespiratory fitness and physical function.

Co-Creating a Feasible, Acceptable and Safe Home-Based High-Intensity Interval Training Programme for People with Parkinson's: The HIIT-Home4Parkinson's Study.

High-intensity interval training (HIIT) is useful and feasible for some people with Parkinson's (PwP), although long-term adherence may be problematic. If practical, undertaking HIIT in the home setting could be a way to encourage continued participation. However, no home-based HIIT programme has been developed for this population. Therefore, the objectives of this study were to co-create a feasible, accessible, and safe home-based HIIT programme for PwP, including intervention components and logic model. This supports the longer term aim to assess the practicality and utility of home-based HIIT for PwP. The study included three stages. Firstly, an initial HIIT programme and logic model proposal was developed based on existing evidence. This was refined through an iterative, co-creative process of focus groups, exercise testing and interviews involving end-users and relevant stakeholders. Finally, a draft intervention was produced with further co-creator input. During the iterative process, five focus groups, 10 exercise testing sessions and 10 post exercise interviews were undertaken, involving academic researchers, 6 PwP, one family member and two clinicians. These co-creators developed HIIT-Home4Parkinson's (HH4P), a 12-week thrice weekly home-based HIIT programme for PwP based on adaptability, individualisation, and remote support. Despite methodological limitations within the development process, the co-created HH4P programme could be feasible, safe, and useful for PwP. A feasibility study should now be undertaken to address remaining uncertainties prior to a full trial.

High-intensity training in patients with lacunar stroke: A one-year follow-up

ObjectivesPhysical inactivity is a major risk factor for stroke. It is a challenge for patients to initiate and adhere to regular exercise post-stroke. Early initiation of home-based high-intensity interval training (HIIT) may engage patients in physical activity, improve cardiorespiratory fitness, and reduce risk of recurrent stroke. Materials and MethodsPost-intervention follow-up of patients with lacunar stroke, randomized to three-months HIIT including weekly motivational calls, or usual care. At follow-up (six- and 12-months post-stroke), we investigated changes in cardiorespiratory fitness, physical activity, fatigue, depression, mental well-being, stress, cognition, cardiovascular function, and recurrent stroke. ResultsWe included 71 patients of whom 59 patients (mean age: 63.9 ± 8.8 years) completed six- and 12-month follow-up. No change was detected in cardiorespiratory fitness between groups from baseline to 12-months follow-up. At six months, vigorous-intensity activity (median hours/week [interquartile range]) was maintained in the intervention group (baseline, 0[0;2]; post-intervention, 2[0;3]; six-month, 2[0;4]) and increased in the usual care group (baseline, 0[0;1]; post-intervention, 1[0;2]; six-month, 1[0;3]), with no difference between groups. Vigorous-intensity activity declined to baseline levels at 12-months in both groups. Secondary outcomes improved from baseline to 12-months with no significant differences between groups. Similar rate of recurrent stroke (n=3) occurred in each group with a three-month delay in the intervention group. ConclusionsEarly initiated HIIT did not increase long-term cardiorespiratory fitness, but increased time spent doing vigorous-intensity activities post-stroke. Decline to baseline activity level at 12 months warrants identification of motivators to initiate and sustain physical activity post-stroke.

Remote, Whole-Body Interval Training Improves Muscular Endurance and Cardiac Autonomic Control in Young Adults.

High-intensity interval training (HIIT) is an exercise modality acknowledged to maintain physical fitness with more engagement in an active lifestyle compared with other traditional exercise models. Nevertheless, its effects on cardiac control and physical performance in an online-guided setting are not yet clarified. The present work assessed physical fitness and heart rate variability (HRV) before and after an online, home-based HIIT program in college-age students while pandemic lockdowns were in effect. Twenty university students (age: 21.9 ± 2.4 years.) that were solely enrolled in online classes were distributed into three groups: control-CON-(n = 6), 14 min of HIIT-HIIT-14-(n = 8), and 21 min of HIIT-HIIT-21-(n = 6). A maximal push-up test was employed to assess muscular endurance and performance, and resting HRV signals were collected with wireless heart rate monitors and were processed in Kubios HRV Std. (Kubios Oy, Finland). There was an increase in total push-up capacity compared to CON (p < 0.05 HIIT-21 vs. CON; p < 0.001 HIIT-14 vs. CON) after 8 weeks. A significant interaction was observed in high-frequency and low-frequency spectra ratios after the HIIT-21 intervention (p < 0.05). The current work demonstrated that either short- or mid-volume online, whole-body HIIT improves muscle strength, whereas mid-volume HIIT (HIIT-21) was the only intervention that developed a sympathovagal adaptation. This study showed promising results on muscular endurance and cardiac autonomic modulation through whole-body HIIT practice at home.

Abstract P4-11-11: Effect of home-based smartphone-supported high-intensity interval training on cardiorespiratory fitness in breast cancer survivors: A randomized controlled trial of the habit-B program

Abstract Background: A strategy for maintaining and/or improving cardiorespiratory fitness (CRF) in the growing population of cancer survivors is of major clinical importance in the COVID-19 era. With the aim of increasing CRF, recent studies have focused on the use of high-intensity interval training (HIIT) in supervised experimental settings, which appeared to be more beneficial than usual care in cancer survivors at all stages of treatment and aftercare. However, the effect of unsupervised HIIT on increasing CRF in breast cancer survivors is not known. Purpose: To determine whether the newly developed habit-B program, which involves home-based smartphone-supported HIIT using body-weight exercises, improves CRF in early-stage breast cancer survivors. We hypothesized that the habit-B program would improve VO2peak compared with a control group. Methods: This single-center, 12-week, parallel-group, single-blind, randomized controlled trial involved 50 women with stage I-IIa breast cancer, aged 20 to 59 years, who had completed initial treatment except for hormone therapy. Participants wore a smartwatch and were randomized to either the exercise or control group from May 27, 2019 through November 30, 2020. The planned sample size was 60 patients to detect the increase of 2.0 ml/kg/min change in VO2peak with a standard deviation of 2.6 ml/kg/min, one-sided significance level of 2.5% and 80% power. The exercise group underwent home-based HIIT using a smartphone and a Fitbit Versa thrice weekly for 12 weeks (three times per week). The primary outcome was the 12-week change in peak oxygen uptake (VO2peak; mL/kg/min) between the groups. Other outcomes included muscle strength, 6-min walk test, resting heart rate, physical activity, fatigue, safety, and quality of life. Results: Of the 50 participants, 44 (exercise group, n=23; control group, n=21) completed the CRF assessment and 6 did not because of issues related to the COVID-19 pandemic. The change in VO2peak increased significantly in the exercise group (0.9 [95%CI, 0.1 to 1.7]) compared with the control group (-0.8 [95%CI, -1.5 to -0.1]) (mean difference, 1.7 [95% CI, 0.7 to 2.7], p &amp;lt; .01). Leg strength also increased significantly in the exercise group compared with the control group (mean difference, 13.5 [95% CI, 2.9 to 24.1], p &amp;lt; .01). Changes in other outcomes were not significantly different between the groups. Conclusion: A home-based HIIT intervention can lead to improved cardiorespiratory fitness and muscle strength in early-stage breast cancer survivors; however, a multicenter pragmatic clinical trial is required to confirm the benefits of the habit-B program. Table 1.Demographic and medical characteristicsCharacteristicshabit-B (n = 25)Control (n = 25)Age, mean (SD), y48 (6)49 (5)Body mass index, mean (SD), kg/m221.0 (2.2)20.9 (2.0)Diastolic blood pressure, mean (SD), mmHg78 (8)81 (10)Systolic blood pressure, mean (SD), mmHg119 (13)129 (11)Alcohol consumption, n (%)≤weekly8 (32)5 (20)1–6 drinks per week15 (60)19 (76)Daily2 (8)1 (4)Highest Education, n (%)Junior high school0 (0)1 (4)High school3 (12)0 (0)College or more22 (88)24 (96)Employment status, n (%)Full- or part-time worker21 (84)21 (84)On leave1 (4)0 (0)Housewife3 (12)4 (16)Time the patient can use for herself, n (%)&amp;lt;14 hours/week10 (40)5 (20)14–25 hours/week8 (32)11 (44)&amp;gt;25 hours/week7 (28)9 (36)Past history of medical illness, n (%)6 (24)6 (24)Breast cancer stageI18 (72)18 (72)IIA7 (28)7 (28)TumorEstrogen receptor positive24 (96)25 (100)Progesterone receptor positive24 (96)24 (96)HER2 positive1 (4)0 (0)Receiving hormone therapy, n (%)24 (96)23 (92)Tamoxifen, n (%)18 (72)18 (72)Anastrozole, n (%)1 (4)4 (16)Other, n (%)5 (20)1 (4)Receiving radiotherapy, n (%)11 (44)12 (48)Time since surgery, mean (SD) months5 (4)6 (4) Table 2.Changes in cardiorespiratory fitness and muscle strength from baseline to week 12habit-B (n = 21)Control (n = 23)Between-group differenceMean (SD)Mean (SD)Mean (95% CI)ESpPrimary endpointVO2peak (ml/kg/min)Baseline25.0 (3.0)24.9 (4.6)Week 1225.9 (2.8)24.1 (4.0)Within-group difference0.9 (1.7)-0.8 (1.6)1.7 (0.7 to 2.7)1.06&amp;lt;0.01Secondary endpointCardiorespiratory fitness6-min walk test (m)Baseline586 (43)603 (59)Week 12615 (42)631 (68)Within-group difference30 (30)29 (40)1 (-21 to 23)0.260.93VO2peak (L/min)Baseline1.33 (0.18)1.32 (0.29)Week 121.39 (0.23)1.29 (0.26)Within-group difference0.06 (0.11)-0.03 (0.09)0.10 (0.03 to 0.16)0.95&amp;lt;0.01Muscle strengthGrip strength (kgw)Baseline22.4 (3.8)23.3 (4.2)Week 1223.2 (4.2)23.7 (3.4)Within-group difference0.8 (2.0)0.4 (2.1)0.4 (-0.9 to 1.6)0.260.53Leg press one-repetition maximum (kg)Baseline93.6 (24.3)98.7 (40.6)Week 12106.6 (26.7)98.2 (30.9)Within-group difference13.0 (15.9)-0.5 (18.1)13.5 (2.9 to 24.1)0.790.01Chair stand test (s)Baseline14.4 (3.2)13.7 (2.5)Week 1213.5 (2.9)13.3 (2.5)Within-group difference-0.9 (2.7)-0.4 (1.8)-0.5 (-1.9 to 0.9)-0.210.50 Citation Format: Eisuke Ochi, Katsunori Tsuji, Tomomi Narisawa, Yoichi Shimizu, Aya Kuchiba, Akihiko Suto, Kenjiro Jimbo, Shin Takayama, Taro Ueno, Naomi Sakurai, Yutaka J Matsuoka. Effect of home-based smartphone-supported high-intensity interval training on cardiorespiratory fitness in breast cancer survivors: A randomized controlled trial of the habit-B program [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P4-11-11.

Home-based high-intensity interval training can improve physical performance in young female athletes during a quarantine

Aim: To verify the effects of a 2-week of high-intensity interval training (HIIT) on physical performance in young female athletes. Methods: female rugby players (n = 13; 15.92 ± 0.76 years old) participated in an 8-session of HIIT supervised through online video calls for two weeks. They were evaluated pre- and post-HIIT for 3-min of burpees, 1-min of sit-ups, maximum push-ups, and 1-min of squats. Perceptions related to training protocols were collected through the Physical Activity Enjoyment Scale (PACES) post-intervention. Results: Significant improvements in burpees (pre:54.15 ± 18.03 and after: 63.15 ± 15.18), sit-ups (pre:24.38 ± 13.38 and after: 31.15 ± 13.15), push-ups (pre: 9.46 ± 6.59 and after: 13.85 ± 7.33) and squats (pre: 48.00 ± 8.37 and after: 54.85 ± 8.79) were observed. PACES revealed positive perceptions related to the enjoyment of participating in this HIIT. Conclusion: Virtually supervised HIIT improved physical performance in young female athletes during the COVID-19 pandemic, and maybe an efficient strategy for the quarantine period.

Home-Based HIIT and Traditional MICT Prescriptions Improve Cardiorespiratory Fitness to a Similar Extent Within an Exercise Referral Scheme for At-Risk Individuals

Exercise referral schemes (ERS) are used to promote physical activity within primary care. Traditionally, ERS are conducted in a gym or leisure-center setting, with exercise prescriptions based on moderate-intensity continuous training (MICT). Home-based high-intensity interval training (Home-HIIT) has the potential to reduce perceived barriers to exercise, including lack of time and access to facilities, compared to traditional MICT prescription used with ERS and improve health related outcomes. We hypothesized that Home-HIIT would mediate greater improvement in cardiorespiratory fitness (CRF) by virtue of greater adherence and compliance to the exercise prescription, compared to MICT.Methods: Patients enrolled on an ERS (Liverpool, United Kingdom) were recruited for a pragmatic trial. Participants self-selected either 12 weeks of MICT (45–135 min/week at 50–70% HRmax) or Home-HIIT (4–9 min × 1 min intervals at ≥80% of HRmax, interspersed with 1 min rest). The primary outcome was the change in CRF (VO2peak) at post-intervention (12 weeks) and follow-up (3-month post intervention), using intention-to-treat analysis.Results: 154 participants (age 48 ± 10y; BMI 30.5 ± 6.1 kg/m2) were recruited between October 2017 and March 2019, 87 (56%) participants chose Home-HIIT and 67 (44%) MICT. VO2peak increased post-intervention in both groups (MICT 3.9 ± 6.0 ml.kg–1.min–1, Home-HIIT 2.8 ± 4.5 ml.kg–1.min–1, P < 0.001), and was maintained at follow-up (P < 0.001). Fat mass was only reduced post MICT (MICT −1.5 ± 6.3 kg, P < 0.05, Home-HIIT −0.2 ± 2.0 kg, P = 1.00), but the reduction was not maintained at follow-up (MICT −0.6 ± 5.1 kg, Home-HIIT 0.0 ± 2.2 kg, P > 0.05). Adherence to the prescribed programs was similar (MICT 48 ± 35%, Home-HIIT 39 ± 36%, P = 0.77).Conclusion: This is the first study to evaluate the use of Home-HIIT for individuals in a primary care setting. Contrary to our hypothesis, adherence to both exercise prescriptions was poor, and CRF improved to a similar extent in both groups with improvements maintained at 3-month follow-up. We provide evidence that, although not superior, Home-HIIT could be an effective and popular additional exercise choice for patients within primary care based ERS.Clinical Trial Registration: [ClinicalTrials.gov], identifier [NCT04553614].

Adherence to High-Intensity Interval Training in Cardiac Rehabilitation: A REVIEW AND RECOMMENDATIONS.

High-intensity interval training (HIIT) is gaining popularity as a training approach for patients attending cardiac rehabilitation (CR). While the literature has focused on the efficacy of HIIT for improving cardiorespiratory fitness (CRF), particularly when compared with moderate intensity exercise, less emphasis has been placed on adherence to HIIT. The aim of this review was to summarize the current literature regarding adherence to HIIT in CR patients with coronary artery disease. A review identified 36 studies investigating HIIT in CR patients with coronary artery disease. Methods and data were extracted for exercise or training adherence (to attendance, intensity, and duration), feasibility of protocols, and CRF. The review summarizes reporting of adherence; adherence to HIIT and comparator/s; the influence of adherence on changes in CRF; and feasibility of HIIT. Adherence to the attendance of HIIT sessions was high and comparable with moderate-intensity exercise. However, adherence to the intensity and duration of HIIT was variable and underreported, which has implications for determining the treatment effect of the exercise interventions being compared. Furthermore, additional research is needed to investigate the utility of home-based HIIT and long-term adherence to HIIT following supervised programs. This review provides recommendations for researchers in the measurement and reporting of adherence to HIIT and other exercise interventions to facilitate a sufficient and consistent approach for future studies. This article also highlights strategies for clinicians to improve adherence, feasibility, and enjoyment of HIIT for their patients.

Short-term and Long-term Feasibility, Safety, and Efficacy of High-Intensity Interval Training in Cardiac Rehabilitation

High-intensity interval training (HIIT) is recognized as a potent stimulus for improving cardiorespiratory fitness (volume of oxygen consumption [VO2] peak) in patients with coronary artery disease (CAD). However, the feasibility, safety, and long-term effects of HIIT in this population are unclear. To compare HIIT with moderate-intensity continuous training (MICT) for feasibility, safety, adherence, and efficacy of improving VO2 peak in patients with CAD. In this single-center randomized clinical trial, participants underwent 4 weeks of supervised training in a private hospital cardiac rehabilitation program, with subsequent home-based training and follow-up over 12 months. A total of 96 participants with angiographically proven CAD aged 18 to 80 years were enrolled, and 93 participants were medically cleared for participation following a cardiopulmonary exercise test. Data were collected from May 2016 to December 2018, and data were analyzed from December 2018 to August 2019. A 4 × 4-minute HIIT program or a 40-minute MICT program (usual care). Patients completed 3 sessions per week (2 supervised and 1 home-based session) for 4 weeks and 3 home-based sessions per week thereafter for 48 weeks. The primary outcome was change in VO2 peak during the cardiopulmonary exercise test from baseline to 4 weeks. Further testing occurred at 3, 6, and 12 months. Secondary outcomes were feasibility, safety, adherence, cardiovascular risk factors, and quality of life. Of 93 randomized participants, 78 (84%) were male, the mean (SD) age was 65 (8) years, and 46 were randomized to HIIT and 47 to MICT. A total of 86 participants completed testing at 4 weeks for the primary outcome, including 43 in the HIIT group and 43 in the MICT group; 69 completed testing at 12 months for VO2 peak, including 32 in the HIIT group and 37 in the MICT group. After 4 weeks, HIIT improved VO2 peak by 10% compared with 4% in the MICT group (mean [SD] oxygen uptake: HIIT, 2.9 [3.4] mL/kg/min; MICT, 1.2 [3.4] mL/kg/min; P = .02). After 12 months, there were similar improvements from baseline between groups, with a 10% improvement in the HIIT group and a 7% improvement in the MICT group (mean [SD] oxygen uptake: HIIT, 2.9 [4.5] mL/kg/min; MICT, 1.8 [4.3] mL/kg/min; P = .30). Both groups had high feasibility scores and low rates of withdrawal due to serious adverse events (3 participants in the HIIT group and 1 participant in the MICT group). One event occurred following exercise (hypotension) in the HIIT group. Over 12 months, both home-based HIIT and MICT had low rates of adherence (HIIT, 18 of 34 [53%]; MICT, 15 of 37 [41%]; P = .35) compared with the supervised stage (HIIT, 39 of 44 [91%]; MICT, 39 of 43 [91%]; P > .99). In this randomized clinical trial, a 4-week HIIT program improved VO2 peak compared with MICT in patients with CAD attending cardiac rehabilitation. However, improvements in VO2 peak at 12 months were similar for both groups. HIIT was feasible and safe, with similar adherence to MICT over 12-month follow-up. These findings support inclusion of HIIT in cardiac rehabilitation programs as an adjunct or alternative modality to moderate-intensity exercise. Australian New Zealand Clinical Trials Registry Identifier: ACTRN12615001292561.

Cardiac rehabilitation in the paediatric Fontan population: development of a home-based high-intensity interval training programme.

We evaluated the safety and feasibility of high-intensity interval training via a novel telemedicine ergometer (MedBIKE™) in children with Fontan physiology. The MedBIKE™ is a custom telemedicine ergometer, incorporating a video game platform and live feed of patient video/audio, electrocardiography, pulse oximetry, and power output, for remote medical supervision and modulation of work. There were three study phases: (I) exercise workload comparison between the MedBIKE™ and a standard cardiopulmonary exercise ergometer in 10 healthy adults. (II) In-hospital safety, feasibility, and user experience (via questionnaire) assessment of a MedBIKE™ high-intensity interval training protocol in children with Fontan physiology. (III) Eight-week home-based high-intensity interval trial programme in two participants with Fontan physiology. There was good agreement in oxygen consumption during graded exercise at matched work rates between the cardiopulmonary exercise ergometer and MedBIKE™ (1.1 ± 0.5 L/minute versus 1.1 ± 0.5 L/minute, p = 0.44). Ten youth with Fontan physiology (11.5 ± 1.8 years old) completed a MedBIKE™ high-intensity interval training session with no adverse events. The participants found the MedBIKE™ to be enjoyable and easy to navigate. In two participants, the 8-week home-based protocol was tolerated well with completion of 23/24 (96%) and 24/24 (100%) of sessions, respectively, and no adverse events across the 47 sessions in total. The MedBIKE™ resulted in similar physiological responses as compared to a cardiopulmonary exercise test ergometer and the high-intensity interval training protocol was safe, feasible, and enjoyable in youth with Fontan physiology. A randomised-controlled trial of a home-based high-intensity interval training exercise intervention using the MedBIKE™ will next be undertaken.

Abstract OT3-12-01: Effect of home-based high-intensity interval training and behavioral modification using information and communication technology on cardiorespiratory fitness and exercise habits among sedentary breast cancer survivors: The habit-B randomized controlled trial in progress

Abstract Maintaining high levels of physical activity not only helps to maintain and improve physical health and quality of life, but also plays a role in reducing adverse effects due to cancer treatments. Moreover, a greater degree of cardiorespiratory fitness is associated with reduced risk of all-cause mortality in breast cancer survivors. However, there are no home-based programs for improving cardiorespiratory fitness using body weight exercises for breast cancer survivors. This study assesses the efficacy of the newly developed habit-B program (12-weeks, high-intensity interval training exercise, exercise counseling + guidance, home-based exercise support using information and communication technology, and a wearable device (fitbit versa®)) on peak oxygen uptake (VO2peak; mL/kg/min) compared with treatment as usual. This is a parallel-group, single blind, randomized controlled trial. Subjects are sedentary women aged 20 to 59 years who have received breast surgery in the past 2 to 13 months after diagnosis of invasive breast cancer (Stage I-IIa) and have never received chemo-therapy except for hormone therapy. The primary outcome is difference of change in VO2peak between the groups after 12 weeks. The planned sample size is 60 patients to detect the increase of 2.0 ml/kg/min change in VO2peak with a one-sided significance level of 2.5% and 80% power. The effects of this program on exercise habits, physical activity, physical fitness, fatigue, health-related quality of life, and psychological distress are also be investigated. We have already enrolled 6 subjects as of 2019.7.2, and study will be planned to be finished by 2020 April. Citation Format: Katsunori Tsuji, Eisuke Ochi, Yoichi Shimizu, Aya Kuchiba, Tomomi Narisawa, Yuri Ishino, Ryo Okubo, Taro Ueno, Taichi Shimazu, Takayuki Kinoshita, Naomi Sakurai, Yutaka Matsuoka. Effect of home-based high-intensity interval training and behavioral modification using information and communication technology on cardiorespiratory fitness and exercise habits among sedentary breast cancer survivors: The habit-B randomized controlled trial in progress [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr OT3-12-01.

The effect of home-based low-volume, high-intensity interval training on cardiorespiratory fitness, body composition and cardiometabolic health in women of normal body mass and those with overweight or obesity: protocol for a randomized controlled trial

BackgroundThere is a high prevalence of women in South Africa with overweight and obesity which is associated with an increased risk of cardiometabolic disorders. Perceived barriers such as lack of time and motivation reduce engagement in beneficial activity behaviours for health. High-intensity interval training (HIIT) is a time-efficient and effective way to improve cardiometabolic risk profile regardless of a loss in body mass or change in body composition. This randomized controlled trial aims to determine the effects on cardiorespiratory fitness, body composition and cardiometabolic health and feasibility of a home-based 14-week HIIT program in women with overweight/obesity or normal body mass.MethodsOne hundred and twenty women (18–40 years old) with a body mass index between 20 and 35 kg/m2, will be stratified according to their BMI (normal, BMI 20–24.9 kg/m2; or high BMI ≥25 kg/m2) and randomized into a HIIT exercising group (HIIT) or a non-exercising control group (CON). HIIT participants will perform exercises for 11 min/session six times per week for a period of 14 weeks. The 2 × 4 HIIT protocol will require a work phase of own-body weight exercise lasting 2 minutes (85% VO2peak), repeated four times and separated by a one-minute active rest phase (65% VO2peak). CON participants will be asked to maintain their normal habitual lifestyle. Outcomes of cardiorespiratory fitness, body composition, echocardiography, central blood pressure, arterial stiffness and biomarkers of cardiometabolic health will be measured before and after the 14-week intervention. Every 4 weeks during the intervention, an objective estimation of compliance to the study protocol will be assessed by measuring participant physical activity over 7 days using an Actigraph GT3X accelerometer.DiscussionSupervised laboratory-based HIIT interventions are effective in improving cardiometabolic health. More pragmatic exercise protocols may however show to be successful for mitigating barriers to the engagement in physical activity and exercise resulting in positive benefits to health. Investigation into home-based HIIT regimens are important in women, where globally the rising trend of overweight and obesity overshadows that of men. The results from this study may therefore inform future research on effective exercise prescription for women’s health.Trial registrationPan African Clinical Trial Registry (www.pactr.org - id no: PACTR201806003434299), 6th June 2018.

Home-based high-intensity interval training reduces barriers to exercise in people with type 1 diabetes.

What is the topic of this review? This symposium review provides an overview of the recent work investigating whether a virtually monitored home-based high-intensity interval training (Home-HIT) intervention reduces the fear of hypoglycaemia and other common barriers to exercise in people with type 1 diabetes. What advances does it highlight? Home-HIT seems to offer a strategy to reduce fear of hypoglycaemia, while simultaneously removing other known barriers that prevent people with type 1 diabetes from taking up exercise, because it is time efficient, requires no travel time or costs associated with gym memberships, and allows people to exercise in their chosen environment. People with type 1 diabetes (T1D) are recommended to engage in regular exercise for a variety of health and fitness reasons. However, many lead a sedentary lifestyle and fail to meet the physical activity guidelines, in part because of the challenge of managing blood glucose concentration and fear of hypoglycaemia. A number of strategies designed to help people with T1D to manage their blood glucose during and after exercise have been investigated. Although many of these strategies show promise in facilitating blood glucose management during and after exercise, they do not target the many other common barriers to exercise that people with T1D face, such as difficulty with cost and travel time to gyms, limited access to exercise bikes and treadmills, and a possible dislike of exercising in front of others in public places. In this symposium review, we provide an overview of ongoing research into a virtually monitored home-based high-intensity interval training (Home-HIT) programme that is designed to reduce these other common barriers to exercise. The conclusion of this review is that Home-HIT seems to offer a strategy to reduce fear of hypoglycaemia, while simultaneously removing other known barriers preventing people with T1D from taking up exercise, such as being time efficient, requiring no travel time or costs associated with gym memberships, and giving them the opportunity to exercise in their chosen environment, reducing the embarrassment experienced by some when exercising in public.