Impact of Postprandial 'Exercise Snacks' on Protein and Glucose Metabolism Following a Period of Step Reduction in Older Adults

The Impact of Postprandial 'Exercise Snacks' on Protein and Glucose Metabolism Following a Period of Step Reduction in Older Adults

The purpose of this study is to assess the impact of 3-days reduced physical activity (<1500 steps/day) with/without 'exercise snacks' (15 chair stands with calf raises every 30 min) on skeletal muscle metabolic health.

Study Overview

• Status: Recruiting
• Conditions: Nervous System Diseases; Neurologic Manifestations; Neuromuscular Manifestations; Pathological Conditions, Anatomical; Atrophy; Sarcopenia; Muscular Atrophy; Aging; Healthy Aging; Inactivity, Physical
• Intervention / Treatment: Behavioral: Metabolic Trial; Behavioral: 15 sit-to-stands with calf raises

Detailed Description

Many adults gradually lose muscle size, strength, and function after the age of 50. These losses are believed to occur faster with periods of reduced activity (e.g., lower step counts or physical movement when sick or injured) and can be difficult to regain by merely returning to a previously normal activity status. Such periods of reduced activity can also impair the body's ability to use the nutrients in the food consumed (e.g., proteins and carbohydrates), which increases the risk of frailty, type 2 diabetes, and ultimately a reduced quality of life. It is important to identify strategies to prevent these losses in muscle size, strength, and function especially during periods of reduced activity.

Recently, our laboratory has found that performing repeated bodyweight chair squats (repeated sit-to-stands with a calf raise) during a single day of reduced activity improves the muscle's ability to use carbohydrates and proteins, which may be a viable strategy to offset the negative effects of step reduction on muscle health.

In this study, the investigators will assess whether completing bodyweight chair squats at regular intervals (i.e., 'exercise snacks') reduces the negative effects of step reduction on carbohydrate and protein metabolism following a meal. The investigators will determine the impact of 'exercise snacks' (15 chair stands with calf raises every 30 min) compared to seated rest on protein and carbohydrate metabolism following three days of step reduction. The investigators will also assess how these responses compare to those seen following three days of normal (i.e., habitual) activity.

• Study Type: Interventional
• Enrollment (Estimated): 20
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Daniel R Moore, PhD; Phone Number: 4169464088; Email: dr.moore@utoronto.ca
• Study Contact Backup: Name: Matthew J Lees, PhD; Email: matthew.lees@utoronto.ca

Study Locations

• Canada
  • Ontario
    • Toronto, Ontario, Canada, M5S 2C9
      • Recruiting
      • Goldring Center for High Performance Sport
      • Contact: Matthew J Lees, PhD; Phone Number: 416-946-0400; Email: matthew.lees@utoronto.ca
      • Contact: Hugo JW Fung, PhD (c); Email: hugojernwai.fung@utoronto.ca

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Healthy older (age: 60-80 y) adults
• BMI between normal to overweight (18.5-29.9 kg/m2)

Exclusion Criteria:

• Regular use of nonsteroidal anti-inflammatory drugs (with the exception of daily low-dose aspirin)
• Alcohol consumption during the study period
• Use of anticoagulants
• Use of a walker, cane, or assistive walking device
• Current or recently remised cancer
• Infectious or gastrointestinal disease
• Inability to comply with study protocol (e.g., >1,500 steps/day during Step-Reduction Phase)
• Regular tobacco use
• Self-reported illicit drug use (e.g. growth hormone, testosterone, etc.)
• Diagnosed chronic illness (e.g. type 2 diabetes, heart disease, thyroid disease)
• Hormonal Replacement Therapy

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Other: Habitual Activity; Following three days of habitual activity, a metabolic trial will be completed wherein participants (10M/10F) will be assessed for their anabolic response to a protein-carbohydrate meal.	Behavioral: Metabolic Trial; Participants will undergo a metabolic trial to assess for their anabolic response to a protein-carbohydrate meal.
Experimental: Step-Reduction; Participants will undergo three days of reduced physical activity (<1,500 steps/day) prior to a metabolic trial to establish their anabolic response to a protein-carbohydrate meal.	Behavioral: Metabolic Trial; Participants will undergo a metabolic trial to assess for their anabolic response to a protein-carbohydrate meal.; Behavioral: 15 sit-to-stands with calf raises; Participants (n=10; 5F/5M) will be randomized to perform 15 sit-to-stands with calf raises every 30 minutes for the 4 hour duration between muscle biopsies; Other Names: Exercise Snacks

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Myofibrillar protein synthesis rates	Myofibrillar protein synthesis rates assessed by incorporation of oral stable isotope tracer in both arms.	5 Hours

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Whole-body protein turnover	Whole-body protein turnover assessed by oral stable isotope tracers in both arms.	5 Hours
Amino acid oxidation and net protein balance	Amino acid oxidation and net protein balance assessed by oral tracers in both arms. Net protein balance is derived from the difference between amino acid intake (known) and total amino acid oxidation over the 5h measurement period.	5 Hours
Postprandial insulin area under the curve (AUC) to mixed macronutrient breakfast	The plasma insulin concentration measured by enzyme-linked immunosorbent assay (ELISA) area under the curve (AUC) will be quantified using the trapezoidal rule.	5 Hours postprandial
Postprandial glucose area under the curve (AUC) to mixed macronutrient breakfast	The plasma glucose concentration measured by hexokinase method area under the curve (AUC) will be quantified using the trapezoidal rule.	5 hours postprandial

Collaborators and Investigators

• Sponsor: University of Toronto
• Investigators: Study Director: Hugo JW Fung, PhD, University of Toronto; Principal Investigator: Daniel R Moore, PhD, University of Toronto

Study record dates

Study Major Dates

• Study Start (Actual): April 1, 2023
• Primary Completion (Estimated): March 1, 2024
• Study Completion (Estimated): August 1, 2024

Study Registration Dates

• First Submitted: February 21, 2023
• First Submitted That Met QC Criteria: March 30, 2023
• First Posted (Actual): April 12, 2023

Study Record Updates

• Last Update Posted (Actual): July 13, 2023
• Last Update Submitted That Met QC Criteria: July 11, 2023
• Last Verified: July 1, 2023

More Information

Terms related to this study

• Keywords: Physical Activity; Aging; Skeletal Muscle; Step-Reduction; Anabolic Resistance; Stable Isotopes
• Additional Relevant MeSH Terms: Nervous System Diseases; Sarcopenia; Muscular Atrophy; Atrophy; Neurologic Manifestations; Neuromuscular Manifestations; Pathological Conditions, Anatomical
• Other Study ID Numbers: ESPEN

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No