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Timed Exercise Study

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT04097886
Recruitment Status : Completed
First Posted : September 20, 2019
Last Update Posted : September 20, 2019
Information provided by (Responsible Party):
Julie Pendergast, University of Kentucky

Brief Summary:
The purpose of this study was to investigate the effect of timed exercise on human circadian rhythms. Subjects were randomized to 5 days of morning or evening treadmill exercise. A measure of internal circadian timing, or phase, was measured at baseline and following the exercise intervention. Change in circadian phase was compared between the morning and evening group.

Condition or disease Intervention/treatment Phase
Circadian Timing - Exercise Other: Morning Exercise Other: Evening Exercise Not Applicable

Detailed Description:
This study investigated the effect of morning versus evening exercise on internal circadian timing, or phase. Young, sedentary subjects were recruited for this study. Baseline measures included anthropometric, body composition, cardiorespiratory fitness, chronotype, and circadian phase. Subjects were randomized to 5 consecutive days of morning or evening exercise. Thirty minutes of exercise was performed at the designated time and intensity was maintained at a heart rate corresponding with 70% peak VO2. The measure of circadian phase was salivary dim light melatonin onset, indicated by the time when saliva melatonin concentration exceeded 4pg/ml. Post-exercise circadian phase was measured the evening following the last day of exercise. Changes in circadian phase were compared between morning and evening groups.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 67 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)
Primary Purpose: Basic Science
Official Title: Investigating the Effects of Timed Exercise on Human Circadian Rhythms
Actual Study Start Date : June 27, 2017
Actual Primary Completion Date : March 9, 2019
Actual Study Completion Date : March 9, 2019

Resource links provided by the National Library of Medicine

Arm Intervention/treatment
Experimental: Morning Exercise Group
Participants perform moderate exercise in the morning.
Other: Morning Exercise
moderate intensity exercise (70% VO2 max) each morning for 5 days

Experimental: Evening Exercise Group
Participants perform moderate exercise in the evening.
Other: Evening Exercise
moderate intensity exercise (70% VO2 max) each evening for 5 days

Primary Outcome Measures :
  1. Change in onset (time) of melatonin secretion [ Time Frame: baseline and following completion of exercise intervention (approximately 5 days) ]
    Difference in onset (time at which salivary melatonin exceeds threshhold; 4pg/mL) from baseline to completion of exercise intervention.

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 45 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • BMI 18.5-40.0
  • sedentary; <=2 hrs structured exercise weekly
  • medication free (other than birth control)

Exclusion Criteria:

  • diagnosed conditions that would contraindicate safe participation in physical activity
  • diagnosed psychiatric conditions
  • night or rotating shift work 1-year prior to study
  • travel across time zones within previous 4 weeks
  • having children <2 years of age
  • smoking

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT04097886

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United States, Kentucky
University of Kentucky
Lexington, Kentucky, United States, 40536
Sponsors and Collaborators
Julie Pendergast
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Principal Investigator: Julie Pendergast University of Kentucky

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Responsible Party: Julie Pendergast, Assistant Professor, University of Kentucky Identifier: NCT04097886     History of Changes
Other Study ID Numbers: 45342
First Posted: September 20, 2019    Key Record Dates
Last Update Posted: September 20, 2019
Last Verified: September 2019
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No
Keywords provided by Julie Pendergast, University of Kentucky:
phase shift