A Study of the Effects of Intermittent Fasting on Energy, Hormones, Body Composition, and Performance in Male Runners
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"The study team hopes to learn more about how time restricted eating affects performance and health in male runners."
Age: 20 to 40 years old
Healthy Volunteers: Yes
Keywords: running, intermittent fasting, energy expenditure, hormones, body composition, performance, competitive runners, competitive running
Type: Behavioral study
40 Participants
This study is designed to test the effects of four weeks of time restricted feeding (16 hours fasting and 8 hours feeding). These effects will be compared to four weeks of a more traditional eating pattern (12 hours fasting and 12 hours feeding).

The study team will look at the following in male competitive runners:
• Resting energy expenditure
• Blood markers of metabolism and hunger
• Body composition
• Cardiovascular health
• Substrate utilization (carbohydrate and fat burning)
• Fitness
This study requires

If you decide to take part in this study, you will be responsible for adhering to two, 4-week dietary interventions. During this intervention you will continue your exercise routine that you will adhere to twice. You will also be responsible for logging what you eat daily. You will also be asked to take part in one familiarization session and 4 test days at the Western Human Nutrition Research Center (a total of 5 test days). You will complete 3 questionnaires and undergo various physical and exercise tests. You will also be asked to wear an activity monitor daily to track your movement, exercise, and sleep. In total, you will be enrolled in the study for about 10 weeks.

Who can participate

Inclusion criteria:

  • Runners who are actively running an average of 20 miles per week or more

  • Runners who have participated in a competitive race that is at least 5 km in the last year

  • Have an above average fitness level as determined by a running test

  • Weigh a minimum of 110 lbs

  • Willing to repeat same monthly training protocol during two 4-week interventions

Exclusion criteria:

  • Smoker

  • Take medications that have cardiovascular or metabolic effects

  • Taking dietary supplements

  • Following a restrictive diet including restricting calories or carbohydrates

  • Major injuries in past 3 months

  • Present with any contra-indication to exercise testing (cardiovascular abnormalities) as evaluated by study physician

Benefits and risks of participating

We cannot promise any benefits to you as a result of taking part in this research study.


The study personnel will discuss the risks associated with taking part in this research study.
You will receive comprehensive exercise testing including body composition analysis, VO2max, and nutritional analysis.

You will also be compensated for each test day you participated in at the WHNRC in the form of Amazon.com gift cards. Total compensation will be up to $100 at the completion of the study.
Study duration and period
We expect that you will be in the study for about 10 weeks.
Recruitment period
From May 24, 2018
UC Davis
Davis, CA 95616
Richardson, Christine
Research Topic
  • Fasting
  • Intermittent Fasting
  • Athletic Performance
  • Cardiovascular Risk Factor
  • Resting Energy Expenditure

Have any questions or want to learn more? Leave your contact details below and the research team will reach out to you.


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