Leucine or Protein Supplementation and Resistance Training

NCT03501628 | Completed

• 1 other identifier: 15-320 MR 1508
• Study Type: interventional
• Target: 89
• Locations: 0 countries
• Sites: N/A

Brief Summary

The purpose of this study was to determine the effects of L-leucine (LEU) or different protein supplements standardized to LEU (\~3.0 g/serving) on changes in body composition, strength, and histological attributes in skeletal muscle and adipose tissue. Seventy-five untrained, college-aged males (mean±SE; age=21±1 yr, body mass=79.2±0.3 kg) were randomly assigned to an isocaloric, lipid-, and organoleptically-matched maltodextrin placebo (PLA, n=15), LEU (n=14), whey protein concentrate (WPC, n=17), whey protein hydrolysate (WPH, n=14), or soy protein concentrate (SPC, n=15) group. Participants performed whole-body resistance training three days per week for 12 weeks while consuming supplements twice daily. Skeletal muscle and subcutaneous (SQ) fat biopsies were obtained at baseline (T1) and \~72 h following the last day of training (T39). Tissue samples were analyzed for changes in type I and II fiber cross sectional area (CSA), non-fiber specific satellite cell count, and SQ adipocyte CSA. On average, all supplement groups including PLA exhibited similar training volumes and experienced statistically similar increases in total body skeletal muscle mass determined by dual x-ray absorptiometry (+2.2 kg; time p=0.024) and type I and II fiber CSA increases (+394 µm2 and +927 µm2; time p\<0.001 and 0.024, respectively). Notably, all groups reported increasing Calorie intakes \~600-800 kcal/d from T1 to T39 (time p\<0.001), and all groups consumed at least 1.1 g/kg/d of protein at T1 and 1.3 g/kg/d at T39. There was a training, but no supplementation, effect regarding the reduction in SQ adipocyte CSA (-210 µm2; time p=0.001). Interestingly, satellite cell counts within the WPC (p\<0.05) and WPH (p\<0.05) groups were greater at T39 relative to T1. In summary, LEU or protein supplementation (standardized to LEU content) does not provide added benefit in increasing whole-body skeletal muscle mass or strength above PLA following 3 months of training in previously untrained college-aged males that increase Calorie intakes with resistance training and consume above the recommended daily intake of protein throughout training. However, whey protein supplementation increases skeletal muscle satellite cell number in this population, and this phenomena may promote more favorable training adaptations over more prolonged periods.

Conditions

Skeletal Muscle

Outcome Measures

Primary Outcomes (1)

• Index of skeletal muscle hypertrophy

  Whole-body dual x-ray absorptiometry scan for lean body mass assessment (units in kilograms)

  Pre- and post-intervention assessments (12-week seperation between assessments)

Secondary Outcomes (3)

• Index of muscle hypertrophy at the cellular level

  Pre- and post-intervention assessments (12-week seperation between assessments)

• Index of whole-body adiposity

  Pre- and post-intervention assessments (12-week seperation between assessments)

• Index of cellular adiposity

  Pre- and post-intervention assessments (12-week seperation between assessments)

Study Arms (5)

Placebo

PLACEBO COMPARATOR

2 servings daily Serving information: * 204 kcal * 2.8 g fat * 44.4 g carbohydrate * 0.4 g protein (0 g L-leucine)

Dietary Supplement: Placebo

L-leucine + maltodextrin

EXPERIMENTAL

2 servings daily Serving information: * 200 kcal * 2.0 g fat * 43.1 g carbohydrate * 2.8 g protein (2.8 g L-leucine)

Dietary Supplement: L-leucine + maltodextrin

Whey protein concentrate

EXPERIMENTAL

2 servings daily Serving information: * 184 kcal * 3.5 g fat * 12 g carbohydrate * 26.3 g protein (2.8 g L-leucine)

Dietary Supplement: Whey protein concentrate

Hydrolyzed whey protein concentrate

EXPERIMENTAL

2 servings daily Serving information: * 192 kcal * 4.6 g fat * 12.2 g carbohydrate * 25.4 g protein (2.9 g L-leucine)

Dietary Supplement: Hydrolyzed whey protein concentrate

Soy protein concentrate

EXPERIMENTAL

2 servings daily Serving information: * 266 kcal * 4.5 g fat * 17.2 g carbohydrate * 39.2 g protein (2.9 g L-leucine)

Dietary Supplement: Soy protein concentrate

Interventions

Placebo DIETARY_SUPPLEMENT

Supplementation twice daily (1 serving dose per consumption) of maltodextin while engaging in resistance training 3 times per week for a 12-week period. Supplementation occurred during training and non-training days.

Placebo

L-leucine + maltodextrin DIETARY_SUPPLEMENT

Supplementation twice daily (1 serving dose per consumption) of L-leucine + maltodextin while engaging in resistance training 3 times per week for a 12-week period. Supplementation occurred during training and non-training days.

L-leucine + maltodextrin

Whey protein concentrate DIETARY_SUPPLEMENT

Supplementation twice daily (1 serving dose per consumption) of whey protein concentrate while engaging in resistance training 3 times per week for a 12-week period. Supplementation occurred during training and non-training days.

Whey protein concentrate

Hydrolyzed whey protein concentrate DIETARY_SUPPLEMENT

Supplementation twice daily (1 serving dose per consumption) of hydrolyzed whey protein concentrate while engaging in resistance training 3 times per week for a 12-week period. Supplementation occurred during training and non-training days.

Hydrolyzed whey protein concentrate

Soy protein concentrate DIETARY_SUPPLEMENT

Supplementation twice daily (1 serving dose per consumption) of soy protein concentrate while engaging in resistance training 3 times per week for a 12-week period. Supplementation occurred during training and non-training days.

Soy protein concentrate

Eligibility Criteria

• Age: 19 Years - 35 Years
• Gender Eligibility Details: Males
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• are between the ages of 19-35 and have a body mass index (body mass in kilograms/ height in meters\^2) between 23-30
• are apparently healthy and do not have any known illnesses that are contraindicated for exercise (i.e., hypertension, arrhythmias, or cardiopulmonary diseases), or are not taking medications for these diseases
• have not engaged in lower-body weight training over the past 12 months; this means less than one training session per every two weeks
• have not engaged in lower-body endurance training over the past 12 months; this means that the participant has not run more than 10 miles per week or road-biked/swam more than 2 days per week
• have not consumed nutritional supplements two months prior to the study including hormone boosters, protein supplements, amino acid supplements and/or creatine monohydrate
• are not regular tobacco users, or haven't been over the past 12 months
• do not have any blood clotting issues and/or are on blood-thinning agents or medications

You may not qualify if:

• are not between the ages of 19-35 or have a body mass index (body mass in kilograms/ height in meters\^2) outside the range of 23-30
• have any known illnesses that are contraindicated for exercise (i.e., hypertension, arrhythmias, or cardiopulmonary diseases), or are not taking medications for these diseases
• have engaged in lower-body weight training over the past 12 months
• have engaged in lower-body endurance training over the past 12 months
• have consumed nutritional supplements two months prior to the study including hormone boosters, protein supplements, amino acid supplements and/or creatine monohydrate
• are tobacco users
• have any blood clotting issues and/or are on blood-thinning agents or medications

Sponsors & Collaborators

• Auburn University: lead

MeSH Terms

Interventions

Leucine; maltodextrin; Whey

Intervention Hierarchy (Ancestors)

Amino Acids, Branched-Chain; Amino Acids; Amino Acids, Peptides, and Proteins; Amino Acids, Essential; Milk; Beverages; Diet, Food, and Nutrition; Physiological Phenomena; Dairy Products; Food; Food and Beverages

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, INVESTIGATOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Associate Professor

Study Record Dates

• First Submitted: August 31, 2017
• First Posted: April 18, 2018
• Study Start: August 17, 2016
• Primary Completion: May 17, 2017
• Study Completion: August 17, 2017
• Last Updated: April 18, 2018

Record last verified: 2018-04