The Impact of a 48-hour Fast with or Without Exercise on Immune Cell Metabolism and Glycemic Control in Healthy Active Adults
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- The protocol lists: Fasting + Exercise (FAST+EX): fasting + exercise condition, Fasting only (FAST): Non-exercise fasting condition.
- Who it may be relevant to
- Registry conditions: Fasting, Immune Function, Glucose Tolerance. Basic parameters: 19 years — 35 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- Canada
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
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Official title
The Impact of a 48-hour Fast with or Without Exercise on Immune Cell Function, Bioenergetics, and Glycemic Control in Healthy Active Adults: a Randomized Crossover Trial
Overview
Many individuals engage in fasting for its purported health benefits but the effects of fasting on immune cell and whole body metabolism are not well understood in humans. Moreover, how exercising during a prolonged fast impacts immunometabolic outcomes is unclear. This study will determine how a 2 day fast - performed with or without daily exercise - impacts immune cell bioenergetics, immune cell function, and whole-body glycemic control in healthy active individuals.
Detailed description
Participants will perform two, 48-hour fasts separated by 5 days while wearing a continuous glucose monitor to measure glycemic responses. The order of the trials will be randomized for each participant. The two trials will include an exercise condition (FAST+EX) and a control, non-exercise condition (FAST). During the FAST+EX trial, participants will perform 60 minutes of cycling on each of the two days of the fast. Each bout of exercise will be 60 minutes in duration and consist of 50 minutes of cycling at 60% of predicted heart rate reserve (HRR) followed by 5 x 1-minute intervals at 90% of predicted HRR with 1-minute of passive recovery between each interval. During the FAST trial, participants will be asked to refrain from any structured exercise during the days of the fast. To start the trial, participants will arrive at the lab following an overnight fast. They will consume a standardized meal replacement (Ensure Plus Calories) and blood will be drawn 2 hours post-ingestion. Participants will come to the lab 24 and 48 hours later for subsequent blood draws prior to breaking their fast with the same standardized meal replacement. Another blood sample will be taken 2 hours post-prandial. Participants will be asked to replicate food consumption in each condition for the 24-hour period after they break their fast, and consume the same standardized meal replacement on the morning following the completion of each fast to measure free-living glycemic control 24-hours after a fast performed with or without exercise. There will be a five-day wash out period in between the completion of both trials for all participants.
Interventions
- Other Fasting + Exercise (FAST+EX): fasting + exercise condition
Participants will complete a 48-hour fast. One hour of exercise will be performed on each morning of the fast. - Other Fasting only (FAST): Non-exercise fasting condition
Participant will complete a 48-hour fast. No structured exercise will be performed during each of the fasting days.
Primary outcome measures
- Monocyte mitochondrial respiration [Time frame: Baseline and 48 hours]
Secondary outcome measures (11)
- Alteration in immune cell functions [Time frame: Baseline and 48 hours]
- Change in glucose tolerance [Time frame: Baseline, after 48 hours of fasting, and 24 hours after breaking the fast in free-living condition)]
- Blood pressure [Time frame: Baseline, 24 hours into the fast, and at the end of the fast (48 hours)]
- Rate and level of ketosis [Time frame: Baseline, 24 hours and 48 hours during fasting]
- Compensatory movement behaviour [Time frame: During and 48 hours after the fast]
- Hunger sensation [Time frame: At baseline, 12:00, 18:00 during the first and second day of the fast.]
- Sleep quality [Time frame: Baseline the morning before starting the fast, after 24 hours of fasting, and again after 48 hours of fasting.]
- Affect during exercise [Time frame: Before, during (e.g., at 10, 20, 30, 40, and 50 minutes as well as during intervals 1,2,3,4, and 5 at the end of the intervals as well as during the passive recovery) and following the two exercises conditions (post 5 minutes in a seated position).]
- Remembered Enjoyment [Time frame: 10 minutes after each exercise session.]
- Rate of perceived exertion [Time frame: During both exercise sessions at 10, 20, 30, 40, and 50 minutes as well as during intervals 1, 2, 3, 4, and 5 at the end of the intervals.]
- Glucose homeostasis [Time frame: During and 24 hours after both condition]
Eligibility criteria
Inclusion criteria
- Aged between 19 and 35 years.
- Physically active (engaging in ≥150 minutes of weekly moderate to vigorous physical activity).
Exclusion criteria
- History of cardiometabolic diseases or inflammatory diseases (e.g., chronic obstructive pulmonary disease (COPD), rheumatoid arthritis, cardiovascular disease).
- Individuals currently following a ketogenic diet, low-calorie diet, periodic fasting regimen, or consuming ketogenic supplements (e.g., exogenous ketone drinks).
- Cigarette/vaping smoking.
- Physical limitation that will impair the ability of the participant to perform exercise.
- Individuals having a body mass index (BMI) over 30 kg/m2.
- Cancer diagnosis in the past 5 years.
- Taking anti-inflammatory drugs (e.g., ibuprofen, aspirin, naproxen).
- Being unable to read or communicate in English.
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: Yes
Study design
- Allocation
- Randomized
- Model
- Crossover
- Masking
- Single blind
- Primary purpose
- Other
Study locations
Canada · 1 center
- University of British Columbia Okanagan Campus — Kelowna
Identifiers
NCT: NCT06737224 · H24-01732