Brock Exercise And Supplement Trials

Overview

This study will analyze the effects of Greek yogurt consumption and an 12 week exercise intervention on muscle size, body composition and bone health in untrained, university-aged males.

Full Title of Study: “Effects of Greek Yogurt and Exercise on Muscle Size, Body Composition and Bone Health in Untrained, University-aged Males”

Study Type

• Study Type: Interventional
• Study Design
  • Allocation: Randomized
  • Intervention Model: Parallel Assignment
  • Primary Purpose: Treatment
  • Masking: None (Open Label)
• Study Primary Completion Date: August 30, 2018

Detailed Description

Introduction: Previous research has shown the effectiveness of dairy milk and whey protein on increasing muscle size, optimizing body composition and increasing strength in adult males. However, evidence on the use of high protein/Greek yogurt on muscle size, body composition and bone health is limited in this population. Yogurt contains similar muscle and bone supporting nutrients as milk, yet it offers a host of additional benefits including; increased satiety, probiotic cultures, greater stability, increased variety, more affordable and versatile features such as acting as a vehicle for consumption of other healthful foods. The proposed research will investigate the use of Greek yogurt as an effective post-exercise food to promote healthy body composition and bone health changes in young adult males. Design: Parallel, randomized controlled trial. Participants: 30 (n=15 YOG, n=15 PLA) healthy, untrained university-aged males. Methods: Subjects will undergo a 12-week resistance and plyometric training program (exercising 3 days/week). The YOG group will consume a 200g dose (pro= 20g, carbs= 8 grams, ~110 kcals) of plain 0% Greek yogurt, while the PLA group will consume an isoenergetic, protein-void beverage comprised mainly of maltodextrin (pro= 0g, carbs= 26g, ~110 kcals). Each group will consume 3 doses per day (immediately and 1 hour post-exercise, and bedtime). Markers of bone health (CTx and P1NP) will be taken at baseline, 1 week and 12 weeks to determine acute and total changes. Muscle size, body composition, strength, vertical jump height and nutritional diaries will be measured pre and post intervention and habitual diet maintenance will be encouraged throughout the intervention. Anticipated Results: It is hypothesized that each group will undergo positive changes in the aforementioned measures, however due to the increase in protein and calcium consumption, the yogurt group is predicted to have significantly greater increases in these variables than the placebo group.

Interventions

• Behavioral: Resistance and Plyometric Exercise
  • 12 weeks of Resistance (twice weekly) and Plyometric (once weekly) training
• Dietary Supplement: Greek Yogurt (0% Plain)
  • 200g 3x/day for 12 weeks.
• Dietary Supplement: Placebo – Study Designed Supplement
  • Iso-energetic to yogurt. 3x/day for 12 weeks.

Arms, Groups and Cohorts

• Experimental: Yogurt Group
  • Group will be consuming 200g of Greek Yogurt (Plain, 0%) 3 times daily for 12 weeks
• Placebo Comparator: Study Designed Supplement Group
  • Group will consume an isoenergetic, protein void, maltodextrin-based placebo supplement during the same time points for 12 weeks as well. The Placebo contain maltodextrin and pudding powder to mimic the consistency of Greek yogurt.

Clinical Trial Outcome Measures

Primary Measures

• Muscular Strength
  • Time Frame: Change from Baseline to 12 weeks
  • 1 Repetition Maximum of bench press, seated row, quad extension and hamstring curl
• Muscle Size
  • Time Frame: Change from Baseline to 12 weeks
  • Muscle Size determined by ultrasound at various sites.
• Body Composition
  • Time Frame: Change from Baseline to 12 weeks
  • Body Fat % measured via BodPod and BodyMetrix

Secondary Measures

• Bone cell activity
  • Time Frame: Change from Baseline to 12 weeks
  • Bone markers measured in serum.
• Vertical Jump Height
  • Time Frame: Change from Baseline to 12 weeks
  • measured via chalk-on-wall technique

Participating in This Clinical Trial

Inclusion Criteria

• Male – Age 18-25 years – Normal BMI (18.5-24.9) kg/m2 – Have not participated in a resistance training program (of resistance exercise at least 2x/week or more) in the last 6 months – Healthy and not taking any medication affecting muscle or bone – Not supplementing with vitamins/ minerals or protein – Speak and understand English – No dairy allergy or lactose intolerance

Gender Eligibility: Male

Minimum Age: 18 Years

Maximum Age: 25 Years

Are Healthy Volunteers Accepted: Accepts Healthy Volunteers

Investigator Details

• Lead Sponsor
  • Brock University
• Provider of Information About this Clinical Study
  • Principal Investigator: Andrea Josse, Assistant Professor – Brock University
• Overall Official(s)
  • Andrea Josse, PhD, Principal Investigator, Brock University

Citations Reporting on Results

Bridge A, Brown J, Snider H, Nasato M, Ward WE, Roy BD, Josse AR. Greek Yogurt and 12 Weeks of Exercise Training on Strength, Muscle Thickness and Body Composition in Lean, Untrained, University-Aged Males. Front Nutr. 2019 Apr 30;6:55. doi: 10.3389/fnut.2019.00055. eCollection 2019.