Interval Versus Continuous Exercise During Pregnancy

Study Overview
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Brief Summary
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The objective of this randomized cross-over design was to investigate the fetal well-being and maternal glycemic response to an acute bout of aerobic high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) with pregnant individuals.

Official Title
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Effects of Acute High-intensity Intervals Versus Moderate-intensity Continuous Cycling on Maternal and Fetal Health

Conditions
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Pregnancy Related, Glucose, Low Blood, Fetal Heart Rate or Rhythm Abnormality Affecting Fetus, Fetal Blood Flow

Intervention / Treatment
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* Other: High intensity Interval Training
* Other: Moderate Intensity Continuous Training


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Carrying a singleton pregnancy (i.e. greater than or equal to 20 weeks of gestation). Has access to a stationary bike Located within Canada and/or within Edmonton Alberta Exclusion Criteria: History of smoking within the last year Taking medications that may interfere with cardiovascular function. High-order pregnancies, e.g. twins or above. Females with absolute contraindications (as outlined by the Canadian Guidelines for Physical Activity throughout Pregnancy and the PARMed-X questionnaire)

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 50 Years

Sexes Eligible for Study
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Female

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: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: 1st Exercise session<br>Participants completed either the HIIT or MICT session. | Other: High intensity Interval Training<br>* HIIT protocol consisted of 10 one-minute intervals of high-intensity work (i.e., > 90% HRmax) interspersed with nine one-minute intervals of self-paced active recovery (19-minutes total).<br>Other: Moderate Intensity Continuous Training<br>* The MICT protocol consisted of 30-minutes of moderate intensity cycling (i.e., 64 - 76% HRmax).<br>|
| Experimental: 2nd Exercise session<br>Participants completed the subsequent exercise protocol (i.e. HIIT or MICT) | Other: High intensity Interval Training<br>* HIIT protocol consisted of 10 one-minute intervals of high-intensity work (i.e., > 90% HRmax) interspersed with nine one-minute intervals of self-paced active recovery (19-minutes total).<br>Other: Moderate Intensity Continuous Training<br>* The MICT protocol consisted of 30-minutes of moderate intensity cycling (i.e., 64 - 76% HRmax).<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Flash Glucose Monitor; interstitial Glucose | Measured by a Flash Glucose monitor inserted onto the back of the left tricep | 7-days | 
| Fetal Heart Rate | Measured via ultrasound pre and post exercise | 3-minutes | 
| Fetal Umbilical Blood Flow | Measured Via ultrasound pre and post exercise | 3-minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Maternal Heart Rate | Measured via heart rate monitor; Measured prior to, during, and after exercise. | 40-minutes | 
| Accelerometer | The investigators will objectively measure physical activity using an accelerometer for one week. Average number of minutes per day spent in various activity levels will be determined. | 7-days | 
| Food Log | The investigators will objectively measure nutrients in diet using a seven day food record. This is completed through Food Prodigy/ Food Processor software. | 7-days | 
| Perceived rating of perceived exertion | Borg Scale; Ratings from 6 - 20; Rating of six is minimal perceived exertion and rating of 20 is maximal perceived exertion. | 40-minutes | 
| Cardiovascular fitness | Graded exercise test to volitional fatigue. | 20-minutes | 
| Cerebral Blood Flow of Posterior cerebral artery | Measured using a trans cranial doppler ultrasound. Measured prior to, during, and after exercise. | 40-min | 
| Sleep Quality | The investigators will objectively measure sleep quality using an accelerometer for one week. Average number of hours of sleep per night, time spent awake after sleep onset, and number of awakenings will be determined | 7-days | 
| Rating of Perceived Enjoyment (1-10 Scale) | Rating of 1 is the lowest level of perceived enjoyment, rating of 10 is maximal perceived enjoyment | 40-minutes | 
| Blood pressure | Measured with a finometer; Measured prior to, during, and after exercise. | 40-min | 
| Cardiac Output | Measured with a finometer; Measured prior to, during, and after exercise. | 40-min | 
| Cerebral blood flow of middle cerebral artery | Measured using a trans cranial doppler ultrasound. Measured prior to, during, and after exercise. | 40-minutes | 
| fasted blood sample- sex hormones | Fasted blood samples ( 30ml) will be analyzed for sex hormones (estrogen, progesterone, testosterone). | 5-minutes | 
| Physical Activity Questionnaire | The participants will report physical activity using the pregnancy physical activity questionnaire (gives metabolic equivalent hours per week (MET-hr/week). | 5-minutes | 
| Depression rating | Participants will answer a 10-question questionnaire regarding their mood. A score of 10 or higher is indicative of depressive symptoms. The investigators will report the over number of women in each group who have a score of 10+ at the start and end of the intervention. | 5-minutes | 
| Respiratory measures - respiratory frequency | Breathing frequency (breaths per minute). Measured using spirometry. | 40-minutes | 
| Respiratory measures - tidal volume | Tidal Volume (Liters per breath). Measured using spirometry. | 40-minutes | 
| Respiratory measures - oxygen | Oxygen metabolism (% oxygen used per breath). Measured using a gas analyzer. | 40-minutes | 
| Respiratory measures - carbon dioxide | Carbon Dioxide production (% carbon dioxide per breath). Measured using a gas analyzer. | 40-minutes | 
| Respiratory measures - lung volume | Total Lung Capacity (Liters). Measured using spirometry. | 40-minutes | 
| Fetal Outcome - birth weight | Participants will provide the investigators with birth weight for the infant (grams) | within one month postpartum | 
| fetal outcomes- length | Participants will provide the investigators with birth length for the infant (cm) | within one month postpartum | 
| fetal outcomes- gestational age | Participants will provide the investigators with gestational age at delivery (weeks) | within one month postpartum | 
| maternal outcomes- mode of delivery | Participants will provide the investigators with mode of delivery (vaginal or cesarean). | within one month postpartum | 
| maternal outcomes- delivery complications | Participants will provide the investigators with information regarding any delivery complications. | within one month postpartum | 
| maternal outcomes- pregnancy complications | Participants will provide the investigators with information regarding any pregnancy complications (gestational diabetes, pregnancy induced hypertension, preeclampsia). | any time during study | 
| fetal outcomes- NICU | Participants will provide the investigators with information regarding length (days) of admission to Neonatal Intensive Care Unit (NICU) if applicable | within one month postpartum | 
| maternal outcomes- gestational weight gain | Participants will provide the investigators with the last maternal weight immediately before delivery. This will be used to calculate gestational weight gain (kg; last maternal weight - self reported pre-pregnancy weight). | within one month postpartum |