Clinical trial NCT04000750: Time-Restricted Eating and Muscle Hypertrophy
Official title: The Influence of 16:8 Time-Restricted Eating on Resistance Exercise-Induced Skeletal Muscle Hypertrophy
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Muscle Hypertrophy
Healthy and Well-Trained Men and Women
Keywords: Hypertrophy
Intermittent Fasting
Time Restricted Eating
Protein Signaling
Anabolic
Lead sponsor: California State University, Fullerton
Sponsor class: OTHER
Collaborators: name: San Francisco State University
First posted: 2019-06-27
Enrollment: 20
Sex: ALL
Minimum age (years): 18
Maximum age (years): 35
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: OTHER

Brief summary: 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.

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

Eligibility criteria: 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

Primary outcomes:
measure: Changes in Muscle Size - Lower Body
timeFrame: Pre, Mid (4 weeks), and Post (8 weeks)
measure: Changes in Muscle Size - Upper Body
timeFrame: Pre, Mid (4 weeks), and Post (8 weeks)
measure: Changes in Fiber Type-Specific Size
timeFrame: Pre and Post (week 8)
measure: Changes in Body composition
timeFrame: Pre, Mid (4 weeks), and Post (8 weeks)
measure: Acute Exercise Induced Fiber Type-Specific Anabolic Signaling (Total Concentration and Phosphorylation Status)
timeFrame: Day 1 of exercise training
Secondary outcomes:
measure: Changes in Maximal Strength
timeFrame: Pre and Post (week 8)
measure: Changes in Maximal Muscular Endurance
timeFrame: Pre and Post (week 8)
measure: Changes in Gut Microbiome
timeFrame: Pre, Mid (week 2, 4, 6), and Post (week 8)
measure: Changes in Fiber Type Composition
timeFrame: Pre and Post (week 8)
measure: Changes in Fiber Type-Specific Resting Anabolic Signaling (Total Concentration and Phosphorylation Status)
timeFrame: Pre and Post (week 8)
measure: Changes in Mood
timeFrame: Weekly for duration of the intervention (8 weeks)
measure: Changes in Enjoyment of Diet
timeFrame: Weekly for duration of the intervention (8 weeks)
measure: Changes in Sleep (total and quality)
timeFrame: Weekly for duration of the intervention (8 weeks)
measure: Changes in Menstrual Cycle
timeFrame: Pre, Mid (week 4), and post (week 8)
measure: Total Training Volume
timeFrame: After 8 weeks
measure: Nutrient Intake
timeFrame: Daily, starting 7 days before the study and continuing for 8 additional weeks
Other outcomes:
Locations:
city: Fullerton
country: United States
facility: Center for Sport Performance at California State University, Fullerton
state: California
Study officials:
References: