Effects of Different Moderate-intensity Exercise Methods on Health in the Elderly

Study Overview
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Brief Summary
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Aging is linked to a higher risk of cardiovascular disease. Physical exercise is recognized as an excellent strategy to prevent cardiovascular diseases and cognitive aspects, generating healthier elderly people. The beneficial effects of physical training seem to be greater when performed: In hypoxic conditions (i.e. when the amount of oxygen in the air is decreased as at altitude). With intermittent blood flow restriction (by inflating pneumatic cuffs around the thighs to a pressure that restricts blood flow). This equipment is harmless. With eccentric training (resisting against the movement of the pedal of a bicycle rather than pushing it). The purpose of this study is then to evaluate whether moderate intensity intermittent training can induce similar or greater effects on cardiovascular health when combined with intermittent hypoxia, intermittent blood flow restriction or eccentric training.

Detailed Description
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Aging is associated with a higher risk of cardiovascular disease due mainly to high blood pressure. Physical exercise is recognized as an excellent non-pharmacological strategy to prevent cardiovascular disease and cognitive aspects, thus generating healthier elderly people. Interestingly, living at altitude seems to reduce some cardiovascular risks. In addition, the beneficial effects of physical training seem to be greater when performed under hypoxic conditions (i.e. when the amount of oxygen in the air is decreased as at altitude). Another interesting strategy for the elderly is intermittent blood flow restriction. This involves inflating pneumatic cuffs around the limb(s) to a pressure that blocks or restricts blood flow to the affected muscles, alternating with rest phases. It has been found that endurance training, combined with blood flow restriction, promotes the growth of new blood vessels, which could be particularly important for the prevention of cardiovascular disease in the elderly, which is unfortunately common. Eccentric training is currently emerging as a promising training strategy for the elderly. It consists of resisting the movement of the pedal of a bicycle rather than pushing it. It requires less energy effort than traditional exercise with the same workload. Eccentric training has been shown to improve older adults' body composition and muscle strength, thereby improving exercise capacity and quality of life. These training strategies may be of interest for cardiovascular health in older adults. However, there are few data on their combined effects with exercise in the elderly and there is no consensus to favor one method over another. The objective of this study is then to evaluate whether moderate-intensity intermittent training can induce similar or superior effects on health indicators when combined with intermittent hypoxia, partial vascular occlusion, or eccentric training.

Official Title
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Intermittent Hypoxic vs Blood Flow Restriction vs Eccentric Moderate-intensity Exercise in Elderly

Conditions
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Healthy Aging

Intervention / Treatment
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* Behavioral: Exercise


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: to be aged between 65 and 75 years old not involved in regular physical activities for at least 6 months (i.e., doing no physical exercise over twice per week); free of injuries as well as cardiovascular and respiratory disorders or central nervous system disease or receiving β-blocker medication; not using dietary supplements, smoking or drugs which interfere with the measurements; not using creatine supplementation, anabolic steroids, drugs, or medication with potential effects on physical performance; to have body index mass between 20 and 30 kg/m²; not to live above 800m of altitude; to be vaccinated against COVID-19 and to have no symptoms (fever, cough, fatigue, loss of smell or taste); able to complete all sessions; able to give consent.

Ages Eligible for Study
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Minimum Age: 65 Years
Maximum Age: 75 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: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: This study is designed as a randomized parallel group active-control study.
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Moderate-intensity intermittent training (MIIT)<br>The MIIT will be conducted on a cycle ergometer (Lode Ex. calibur Sport Ergometer, Lode B.V., the Netherlands) in normoxia (FiO2 =   21%). The participants will perform the MIIT starting with the ergometer resistance set to obtain the %HRmax set ( 75-80%) during 5 minutes and will rest 5 minutes after each interval of exercise. The HRmax will be considered as 200 - age. | Behavioral: Exercise<br>* Participants will perform 3 times a week for 4 weeks a moderate intensity interval training.<br>|
| Experimental: MIIT during intermittent hypoxic exposure (IHYP + MIIT)<br>A normobaric hypoxic chamber (ATS Altitude Training, Sydney, Australia) will be used for this protocol. The chamber (2.4 m x 5 m x 2.5 m) allows, via a filter and compressor system, to extract oxygen molecules and to reduce the fraction of inspired oxygen (FiO2) with no modification of the barometric pressure. | Behavioral: Exercise<br>* Participants will perform 3 times a week for 4 weeks a moderate intensity interval training.<br>|
| Experimental: MIIT during intermittent blood flow restriction (IBFR + MIIT)<br>The IBFR + MIIT protocol will be performed while cycling in normoxia (FiO2 =   21%). Elastic, pneumatic cuffs (BStrong, Park City, Utah, USA) will be administered as high as possible at the inguinal crease of the upper thigh and will be inflated during the cycling to the set pressure of 400 mmHg (except for the first training session, it will be of 250 mmHg to minimize soreness and to accustom patients to vascular occlusion training). The cuffs will be deflated at interval rest. | Behavioral: Exercise<br>* Participants will perform 3 times a week for 4 weeks a moderate intensity interval training.<br>|
| Experimental: Moderate-intensity eccentric cycling (MIEC)<br>The MIEC will be conducted on a cycle ergometer (Excalibur, Lode, Groningen, The Nederlands) in normoxia (FiO2 =   21%). The participants will be instructed to resist against the pedal movement (cadence set at 15 revolutions/min) to produce the required torque (set to obtain the 75-80%HRmax) indicated by visual feedback for 5 minutes and will rest 5 minutes after each interval of exercise. The HRmax will be considered as 200 - age. The HR responses will be monitored (Polar Electro Oy, Kempele, Finland). | Behavioral: Exercise<br>* Participants will perform 3 times a week for 4 weeks a moderate intensity interval training.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Blood pressure [mmHg] | a major risk factor, when too high, for cardiovascular diseases. | 4 weeks | 
| Baroreflex sensitivity | A measurement of the mechanism that regulates acute blood pressure changes linked to the development and progression of cardiovascular diseases | 4 weeks | 
| Flow-mediated dilation | RHI index: a measure for arterial endothelial function | 4 weeks | 
| Heart rate variability | An independent predictor of cardiovascular mortality and sudden cardiac death. | 4 weeks | 
| 6-Minute Cycle Test [km] | an estimation of the maximal aerobic capacity | 4 weeks | 
| Knee flexion and extension isokinetic strength [N] | The knee flexion and extension strength will be measured with an isokinetic dynamometer | 4 weeks | 
| Muscle mass [kg] | An analysis of muscle mass will be done using DXA scan | 4 weeks | 
| Body fat [kg] | An analysis of body fat will be done using DXA scan | 4 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Hypoxia, Blood Flow Restriction, Eccentric cycling, Exercice, Elderly