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OpenTrials
Completed

NCT Number: NCT04000750

Time-Restricted Eating and Muscle Hypertrophy

The purpose is to examine the effects of time-restricted eating (TRE; consuming all calories within an 8-hour period each day) vs. normal eating (CON; consuming same kcals and protein as TRE, but during a 10-13 hr eating window each day) during 8 weeks of resistance exercise on body composition and muscle mass (whole muscle and single fiber), muscular performance, anabolic protein signaling, single muscle fiber characteristics, and the gut microbiome in well-trained young men and women.

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Key information

Age range

18 year–35 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Center for Sport Performance at California State University, Fullerton

Fullerton, California, 92831, United States

About this study

The primary goal pertains to muscle hypertrophy (not fat loss), thus all participants will be placed in a 10% caloric surplus.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • 18-35 years old with <25% (men) or <30% (women) body fat
  • have experience in resistance exercise for the whole body and performed resistance exercise at least 3 times per week the last 12 months
  • be able to perform all necessary exercises with safe technique and no pain
  • be able to squat 1.5x (men) or 1x (women) body weight
  • be able to bench press 1.1x (men) or 0.55x (women) body weight
  • be on a non-specialized, mixed macronutrient diet
  • have a lifestyle which enables a reasonably consistent 7+ hours of sleep per night
  • be free of any current joint, musculoskeletal, and/or neuromuscular injuries

Exclusion criteria

  • have any known current illness, prohibitive muscular or neuromuscular problem, hypertension, cardiac, pulmonary, liver, kidney, insulin or any other metabolic disorders (e.g. Type I or Type II diabetes)
  • are lactose intolerant or unable to consume whey protein for any reason
  • are on any medications known to affect protein metabolism
  • have taken antibiotics in the last 6 months
  • cannot refrain from consuming any alcoholic beverages, nicotine, or marijuana (or derivative) for a period of 48 hours prior to data collection (pre and post testing)
  • consume alcohol >2x per week
  • consume any analgesic or anti-inflammatory drug(s), prescription or non-prescription, chronically or within 48 hours of data collection
  • consume any recreational drug(s), prescription or non-prescription, legal or illegal, chronically or within 30 days of data collection
  • consume any caffeine or food within 12 hours of data collection
  • cannot refrain from physical exercise (outside of activities of daily living) outside of what is prescribed by the research team for the duration of the study
  • cannot refrain from using recovery methods such as electric stimulation, hot/cold therapy, massage, chiropractic, or personal air/water devices (Normatech, etc.)
  • have utilized any anabolic steroid, currently or in the past
  • cannot refrain from consumption of any supplementation (creatine, multivitamin, fish oil, protein powder, BCAA, pre-workouts, etc.) outside of what is provided
  • cannot refrain from consuming any supplemental pro or prebiotics or other items that intentionally alter the gut microbiome
  • fail to adhere to the nutritional guidelines or miss >3 of the exercise sessions
  • were recently pregnant, trying to become pregnant, or are currently breastfeeding

Treatment and study plan

Time restricted eating

Other

Diet will be tracked and reported every day to a qualified dietitian.

Normal Feeding

Other

Diet will be tracked and reported every day to a qualified dietitian.

Resistance training

Other

8 weeks of supervised and programmed whole body resistance training, performed 4x per week

Whey Protein

Dietary Supplement

Consumed on all exercise days.

Primary outcomes

  1. Changes in Muscle Size - Lower Body

    Time frame: Pre, Mid (4 weeks), and Post (8 weeks)

    via Ultrasound

  2. Changes in Muscle Size - Upper Body

    Time frame: Pre, Mid (4 weeks), and Post (8 weeks)

    via Ultrasound

  3. Changes in Fiber Type-Specific Size

    Time frame: Pre and Post (week 8)

    Single muscle fiber analysis

  4. Changes in Body composition

    Time frame: Pre, Mid (4 weeks), and Post (8 weeks)

    via BodPod

  5. Acute Exercise Induced Fiber Type-Specific Anabolic Signaling (Total Concentration and Phosphorylation Status)

    Time frame: Day 1 of exercise training

    Men only; assessed via single fiber Simple Western

Secondary outcomes

  1. Changes in Maximal Strength

    Time frame: Pre and Post (week 8)

    1RM on bench press, squat, and leg extension

  2. Changes in Maximal Muscular Endurance

    Time frame: Pre and Post (week 8)

    Maximal repetitions on bench press and leg press

  3. Changes in Gut Microbiome

    Time frame: Pre, Mid (week 2, 4, 6), and Post (week 8)

    via stool sample

  4. Changes in Fiber Type Composition

    Time frame: Pre and Post (week 8)

    Single Fiber via SDS-PAGE

  5. Changes in Fiber Type-Specific Resting Anabolic Signaling (Total Concentration and Phosphorylation Status)

    Time frame: Pre and Post (week 8)

    via single fiber Simple Western

  6. Changes in Mood

    Time frame: Weekly for duration of the intervention (8 weeks)

    via Questionnaire

  7. Changes in Enjoyment of Diet

    Time frame: Weekly for duration of the intervention (8 weeks)

    via Questionnaire

  8. Changes in Sleep (total and quality)

    Time frame: Weekly for duration of the intervention (8 weeks)

    via Questionnaire

  9. Changes in Menstrual Cycle

    Time frame: Pre, Mid (week 4), and post (week 8)

    via Questionnaire; women only

  10. Total Training Volume

    Time frame: After 8 weeks

  11. Nutrient Intake

    Time frame: Daily, starting 7 days before the study and continuing for 8 additional weeks

    Total Kcal and grams of protein, fat, and carbohydrates

Sponsors and collaborators

Lead sponsor

California State University, Fullerton

Other

Collaborators

  • San Francisco State University

Registry information

Official study title

The Influence of 16:8 Time-Restricted Eating on Resistance Exercise-Induced Skeletal Muscle Hypertrophy

Important dates

Study start
2019
Primary completion
2021
Study completion
2023
First posted
Jun 27, 2019
Registry last updated
Feb 9, 2023

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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