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Resistance Exercise and Protein During Weight Loss

Not Applicable
Completed
Conditions
Starvation
Weight Loss
Interventions
Other: Caloric Restriction
Other: Energy Balance
Dietary Supplement: Post-Exercise Carbohydrate
Dietary Supplement: Post-Exercise Protein
Dietary Supplement: Calcium and Vitamin D
Registration Number
NCT03600311
Lead Sponsor
University of Nebraska Lincoln
Brief Summary

The purpose of this study is to determine if post-exercise protein supplementation can rescue the anabolic response of muscle and bone to resistance exercise during caloric restriction.

Detailed Description

1. Preliminary Testing Prior to the study start, participants will be weighed and body composition will be determined using bioimpedance analysis. Then participants will undergo a 5RM barbell back squat exercise testing procedure.

2. Randomization

Participants will proceed through each of the following conditions lasting 3 days:

CON: Participants will be in energy balance and consume 1.2 g protein/kg BW/day. Participants will be provided 30 g maltodextrin post-exercise.

CR+C: Participants will be restricted to 15 kcal/kg FFM/day and consume 1.2 g protein/kg BW/day. Participants will be provided 30 g maltodextrin post-exercise.

CR+P: Participants will be restricted to 15 kcal/kg FFM/day and consume 1.2 g protein/kg BW/day. Participants will be provided 30 g whey protein post-exercise.

3. Diet Prescription Dietary energy intake will be controlled using clinical products, maltodextrin and whey protein isolate to meet target energy intakes. Participants will receive calcium and Vitamin D supplementation throughout the study.

4. Exercise Prescription Participants will perform one bout of 5 sets of 5 repetitions of barbell back squat exercise on the morning of Day 3 each condition. Additional exercise and intense physical activity will be prohibited.

5. Assessments Body weight and composition (DXA + BIA), fasting blood draws for assessment of metabolic and anabolic hormones and questionnaires will be conducted before and after each condition. A 24-hour serial blood draw procedure will be conducted following each workout session on each Day 3.

6. Washout Once a participant completes a study condition, participants will continue to take daily body weights at home for up to one week. Then participants will be required to wait one more week before completing their next condition during which they will resume regular diet and physical activity.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
17
Inclusion Criteria
  • Weigh at least 110 lbs
  • Weight-Stable (2.5 kg) within the past six months
  • Height-Stable (< 0.25 inches) within the past year
  • 3 years of resistance training experience

Tested Inclusion Criteria:

  • <20% body fat (men) or <30% body fat (women)
Exclusion Criteria
  • Lactose intolerant
  • Pregnancy
  • Taking interfering medications such as steroids, thyroid or growth hormones

Study & Design

Study Type
INTERVENTIONAL
Study Design
CROSSOVER
Arm && Interventions
GroupInterventionDescription
Energy BalancePost-Exercise CarbohydrateParticipants will be in energy balance and consume 1.2 g/kg BW protein. They will be provided 30 g of maltodextrin following exercise.
Caloric Restriction and CHO SuppPost-Exercise CarbohydrateParticipants will be calorie restricted to 15 kcal/kg FFM/day and consume 1.2 g/kg BW protein. They will be provided 30 g of maltodextrin following exercise.
Caloric Restriction and CHO SuppCalcium and Vitamin DParticipants will be calorie restricted to 15 kcal/kg FFM/day and consume 1.2 g/kg BW protein. They will be provided 30 g of maltodextrin following exercise.
Caloric Restriction and PRO SuppCaloric RestrictionParticipants will be calorie restricted to 15 kcal/kg FFM/day and consume 1.2 g/kg BW protein. They will be provided 30 g of whey protein following exercise.
Caloric Restriction and PRO SuppPost-Exercise ProteinParticipants will be calorie restricted to 15 kcal/kg FFM/day and consume 1.2 g/kg BW protein. They will be provided 30 g of whey protein following exercise.
Energy BalanceCalcium and Vitamin DParticipants will be in energy balance and consume 1.2 g/kg BW protein. They will be provided 30 g of maltodextrin following exercise.
Energy BalanceEnergy BalanceParticipants will be in energy balance and consume 1.2 g/kg BW protein. They will be provided 30 g of maltodextrin following exercise.
Caloric Restriction and CHO SuppCaloric RestrictionParticipants will be calorie restricted to 15 kcal/kg FFM/day and consume 1.2 g/kg BW protein. They will be provided 30 g of maltodextrin following exercise.
Caloric Restriction and PRO SuppCalcium and Vitamin DParticipants will be calorie restricted to 15 kcal/kg FFM/day and consume 1.2 g/kg BW protein. They will be provided 30 g of whey protein following exercise.
Primary Outcome Measures
NameTimeMethod
Change in Serum [CTX] (ng/mL)Baseline, Pre-Exercise, 0-24 Hours Post-Exercise

Measured via ELISA

Change in Serum [P1NP] (pg/mL)Baseline, Pre-Exercise, 0-24 Hours Post-Exercise

Measured via ELISA

Change in Serum [IGF-1] (ng/mL)Baseline, Pre-Exercise, 0-24 Hours Post-Exercise

Measured via ELISA

Change in Serum [IGFBP-3] (ng/mL)Baseline, Pre-Exercise, 0-24 Hours Post-Exercise

Measured via ELISA

Change in Serum [GH] (pg/mL)Baseline, Pre-Exercise, 0-24 Hours Post-Exercise

Measured via ELISA

Change in Serum [Sclerostin] (pmol/L)Baseline, Pre-Exercise, 0-24 Hours Post-Exercise

Measured via ELISA

Secondary Outcome Measures
NameTimeMethod
Change in Body Weight (kg)Baseline and Day 4

Measured via Stadiometer

Change in Perceived Hunger (mm or %)Baseline and Day 4

Measured on Visual Analog Scale within Survey

Change in Body Fat Percentage (%)Baseline and Day 4

Measured via DXA and BIA

Trial Locations

Locations (1)

Sports and Exercise Nutrition Laboratory, Department of Nutrition and Health Sciences, Ruth Leverton Hall

🇺🇸

Lincoln, Nebraska, United States

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