Healthy and Well-Trained Men and Women, Muscle Hypertrophy
Conditions
Keywords
Hypertrophy, Intermittent Fasting, Time Restricted Eating, Protein Signaling, Anabolic
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.
Interventions
OTHERTime Restricted Eating
Diet will be tracked and reported every day to a qualified dietitian.
OTHERNormal Feeding
Diet will be tracked and reported every day to a qualified dietitian.
OTHERResistance Training
8 weeks of supervised and programmed whole body resistance training, performed 4x per week
DIETARY_SUPPLEMENTWhey Protein
Consumed on all exercise days.
Sponsors
San Francisco State University
California State University, Fullerton
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
OTHER
Masking
DOUBLE (Investigator, Outcomes Assessor)
Masking description
Participants will know their group. Training and Nutrition research team members will know the participants group. Data analysis team will be blinded to condition.
Eligibility
Sex/Gender
ALL
Age
18 Years to 35 Years
Healthy volunteers
Yes
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Changes in Fiber Type-Specific Size | Pre and Post (week 8) | Single muscle fiber analysis |
| Changes in Body composition | Pre, Mid (4 weeks), and Post (8 weeks) | via BodPod |
| Changes in Muscle Size - Lower Body | Pre, Mid (4 weeks), and Post (8 weeks) | via Ultrasound |
| Changes in Muscle Size - Upper Body | Pre, Mid (4 weeks), and Post (8 weeks) | via Ultrasound |
| Acute Exercise Induced Fiber Type-Specific Anabolic Signaling (Total Concentration and Phosphorylation Status) | Day 1 of exercise training | Men only; assessed via single fiber Simple Western |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Changes in Mood | Weekly for duration of the intervention (8 weeks) | via Questionnaire |
| Changes in Enjoyment of Diet | Weekly for duration of the intervention (8 weeks) | via Questionnaire |
| Changes in Sleep (total and quality) | Weekly for duration of the intervention (8 weeks) | via Questionnaire |
| Changes in Maximal Strength | Pre and Post (week 8) | 1RM on bench press, squat, and leg extension |
| Total Training Volume | After 8 weeks | — |
| Nutrient Intake | Daily, starting 7 days before the study and continuing for 8 additional weeks | Total Kcal and grams of protein, fat, and carbohydrates |
| Changes in Menstrual Cycle | Pre, Mid (week 4), and post (week 8) | via Questionnaire; women only |
| Changes in Maximal Muscular Endurance | Pre and Post (week 8) | Maximal repetitions on bench press and leg press |
| Changes in Gut Microbiome | Pre, Mid (week 2, 4, 6), and Post (week 8) | via stool sample |
| Changes in Fiber Type Composition | Pre and Post (week 8) | Single Fiber via SDS-PAGE |
| Changes in Fiber Type-Specific Resting Anabolic Signaling (Total Concentration and Phosphorylation Status) | Pre and Post (week 8) | via single fiber Simple Western |
Countries
United States
Outcome results
None listed