Sprint Snacks: The Effects of Prolonged Rest on Reduced Exertion Interval Training.

Study Overview
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Brief Summary
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An adapted sprint interval training protocol involving 2-3 repeated 20-second sprints separated by 2-3 minutes rest (termed reduced exertion high- intensity interval training (REHIIT)) has been developed and has been shown to promote fitness benefits. This data shows how little exercise one may need to improve cardiorespiratory fitness, provided they are willing to work very hard. However, it is unknown whether the benefits of REHIIT are because of the all-out nature of the sprint efforts themselves or the pattern of completing sprints with relatively short (i.e., minutes) rest periods within a workout session. We are inquiring whether performing the same number and style of sprints with prolonged rest (i.e., 1-4 hours of rest in between sprints) is equally effective for improving aerobic fitness when compared to more traditional sprint interval training with 2-3 minutes of rest between sprints. Such information may make the effectiveness of sprint training more accessible and approachable for individuals unwilling or unable to plan a purposeful REHIIT exercise session into their day. If the rest interval could be prolonged then it may be possible to perform a few sprints as exercise snacks throughout the day without the need for a structured interval training session.

Official Title
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Exercise Sprint Snacks: The Effects of Prolonged Rest, Reduced Exertion High-intensity Interval Training (PR-REHIIT) Compared to Standard Reduced Exertion High-intensity Interval Training (REHIIT).

Conditions
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Cardiorespiratory Fitness

Intervention / Treatment
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* Other: REHIIT
* Other: PR-REHIIT


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Physically inactive (2 or less bouts of purposeful exercise per week) Exclusion Criteria: If your doctor has informed you that you have a heart condition and should only do physical activity recommended by a doctor. If you feel pain in your chest when you perform any physical activity. If in the past the month you have had chest pain when you were not doing any physical activity. If you lose your balance or consciousness because of dizziness. If you have bone or joint problem (for example, back, knee, or hip) that could be made worse by a change in your physical activity. If you are currently pregnant or planning on becoming pregnant in the next 6 weeks. You have previously had a heart attack or stroke You are currently engaging in high-intensity interval training. You are currently physically active (engaging in 3 or more bouts of purposeful exercise per week; a bout is defined as structured, planned exercise lasting at least 30 minutes) You have severe chest pain or blood pressure over 240/140 during baseline testing. You have exercise induced asthma or a history of syncope.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 35 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
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: PR- REHIIT<br>PR-REHIIT participants (Sprint Snacks) will participate in 3 separate training session per day on 3 days per week (i.e., 9 sessions per week). Each session lasts 3 minutes and 20 seconds and consists of a two-minute warm-up, a 20-second all-out sprint, and a one-minute cool-down. There will be 1-4 hours of rest in between training sessions where participants are free to leave the lab and go about their normal day. | Other: PR-REHIIT<br>* PR-REHIIT participants will come into the lab on 3 separate occasions on the training days, which occur 3 days per week (i.e., 9 sessions per week). Each session lasts 3 minutes and 20 seconds and consists of a two-minute warm-up, a 20-second all-out sprint on a cycle ergometer, and a one-minute cool-down. There will be 1-4 hours of rest in between training sessions where participants are free to leave the lab and go about their normal day.<br>|
| Experimental: REHIIT<br>REHIIT participants will come into the lab one time per training days (3 training days per week), each session lasting 10 minutes. Training sessions involve a two-minute warm-up, 3 X 20-second sprints with three minutes rest in between, and a one-minute cool-down. | Other: REHIIT<br>* REHIIT participants will come into the lab one time per training days (3 training days per week), each session lasting 10 minutes. Training sessions involve a two-minute warm-up, 3 X 20-second cycling sprints on an exercise bike with three minutes rest in between, and a one-minute cool-down.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in VO2max | Maximal oxygen uptake assessed using a ramp increase protocol on a cycle ergometer. | Before and after the 6 week intervention | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in 10 km Time Trial Performance | Time to complete a simulated 10 km Time Trial on a Cycle ergometer | Before and after the 6 week intervention | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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VO2max, maximal oxygen uptake