Short-term, Home-based, High-intensity Interval Training (HIT) for Improving Fitness

Study Overview
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Brief Summary
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This study will aim to evaluate the efficacy of a short-term, home-based, high-intensity interval (HIT) programme in improving cardiovascular fitness in healthy volunteers aged 55 and above, with an age-comparison to younger individuals taking part in the same training regime. It will also explore the efficacy of time-matched 'static' interventions for improving cardiovascular parameters in middle-aged females and older adults.

Detailed Description
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Patients with lower peak oxygen uptake have higher mortality and morbidity when undergoing major surgery. Aerobic fitness is a potentially modifiable risk factor for postoperative complications. Traditional pre-operative exercise interventions to improve fitness involve high time and supervision-demands, often resulting in poor compliance. High-intensity interval training (HIT) is a time-efficient, feasible method to improve pre-operative fitness, however current studies only involve exercise in the laboratory setting. Study Design Thirty-six healthy volunteers aged 55y and over will be randomly allocated to one of three groups: 1) Laboratory-HIT; 2) Home-HIT; 3) No intervention. All HIT sessions will involve a brief warm-up, followed by five 1-minute bouts of high-intensity (body-weight based) exercise, interspersed with 90-seconds recovery, concluding with a brief cool-down. The primary endpoint of the study is change in VO2 peak with secondary endpoints of changes in: anaerobic threshold, insulin sensitivity and muscle mass. Subjects will be expected to perform up to a maximum of 16 HIT sessions (maximum 5 sessions per week) within a period of 31 days. Aerobic fitness will be assessed prior to and following the exercise, as will body composition, muscle structure, physical function and insulin sensitivity. For the age comparison, 24 young individuals will be recruited to either a control or home-HIT arm. In addition, the efficacy of time-matched 'static' interventions for improving cardiovascular parameters in 24 middle-aged females will also be assessed as exploratory work for these interventions. The efficacy of the static interventions in older adults at home will also be explored. Power calculation: The investigators performed a power calculation for the primary outcome of VO2 max in older adults using data from a previous study at our centre on home versus laboratory HIIT. Assuming an effect size F of 0.6 for three groups and a within group SD of 5, the alpha level was set at 0.05 and the 1-beta at 0.80. This concluded that 30 participants would be required. To allow for potential non-completion and missing data 36 older participants will be enrolled to the study (12 to each group).

Official Title
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A Randomised Control Trial to Assess the Efficacy of Short-term, Home-based High- Intensity Interval Training (HIT) for Improving Indices of Cardiorespiratory Fitness

Conditions
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High-Intensity Interval Training

Intervention / Treatment
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* Other: High-intensity interval training


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age > 55 years Able to give informed consent Exclusion Criteria: Current participation in a formal exercise regime A BMI < 18 or > 35 kg·m2 Active cardiovascular disease: Uncontrolled hypertension (BP > 160/100) Angina Heart failure (class III/IV) Significant arrhythmia Right to left cardiac shunt Recent cardiac event Taking beta-adrenergic blocking agents Cerebrovascular disease: Previous stroke Aneurysm (large vessel or intracranial) Epilepsy Respiratory disease including: Pulmonary hypertension Significant COPD Uncontrolled asthma Malignancy Metabolic disease e.g. diabetic patients Clotting dysfunction Significant Musculoskeletal or neurological disorders Family history of early (<55y) death from cardiovascular disease

Ages Eligible for Study
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Minimum Age: 55 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Health Services Research
Allocation: Randomized
Intervention Model: Factorial Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Laboratory HIT<br>Supervised (Laboratory HIT) exercise in the lab up to 4 times per week for 4 weeks | Other: High-intensity interval training<br>* 2 minute warm up, followed by 5x1min HIT intervals separated by 90 seconds active recovery (walking on the spot) and then a 2 minute recovery period. The high intensity bouts will be a pyramid of exercises (star jumps, mountain climbers and on-the-spot sprints)<br>* Other names: HIT;|
| Active Comparator: Home HIT<br>Unsupervised (Home HIT) exercise at home up to 4 times per week for 4 weeks | Other: High-intensity interval training<br>* 2 minute warm up, followed by 5x1min HIT intervals separated by 90 seconds active recovery (walking on the spot) and then a 2 minute recovery period. The high intensity bouts will be a pyramid of exercises (star jumps, mountain climbers and on-the-spot sprints)<br>* Other names: HIT;|
| No Intervention: Control Group<br>No intervention | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in VO2 Max (L/min) assessed by Cardio-pulmonary exercise test (CPET) | To determine the efficacy of bodyweight HIT for improving aerobic fitness | 31 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Anaerobic Threshold (L/min) using CPET | To determine the efficacy of bodyweight HIT for improving aerobic fitness | 31 days | 
| Change in resting glucose and insulin sensitivity (mmol/L) | The effects of HIT on improving glucose control using Oral Glucose Tolerance Test (OGTT) and enzyme-linked immunosorbent assay (ELISA) | 31 days | 
| Change in muscle architecture as assessed by ultrasound | To assess the effects of HIT on improving muscle structure and function | 31 days | 
| Change in body composition (fat, muscle, bone (g)) as assessed by Dual-energy Xray Absorptiometry (DEXA) | To assess the effects of HIT on improving muscle structure and function | 31 days | 
| Feasibility of home HIT assessed using a preset feasibility questionnaire | To assess the feasibility and acceptability of performing a HIT programme at home | 31 days | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Home-based, Short-term, Randomised Control Trial