time-restricted eating and muscle hypertrophy

Conditions: Muscle Hypertrophy; Healthy and Well-Trained Men and Women

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.

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

Keywords: hypertrophy intermittent fasting time restricted eating protein signaling anabolic