Fasting and Exercise-induced Changes in Human Skeletal Muscle

Not Applicable

Completed

• Conditions: Skeletal Muscle Energetics

• Registration Number: NCT03811717
• Lead Sponsor: Queen's University

Brief Summary

This study examines the impact of increasing energetic stress during an 8-hour fast on metabolic pathways in human skeletal muscle. Specifically, participants will undergo two 8-hour fasting sessions in a randomized crossover fashion, with the addition of low-intensity arm exercise in one of the sessions. Changes in metabolic pathways will be examined in resting (leg) muscle before, during, and after the fast.

Detailed Description

Not available

Study Timeline

• Study Start: 2019-01-14
• Study First Submitted: 2019-01-17
• Study First Submitted QC: 2019-01-17
• Study First Posted: 2019-01-22
• Primary Completion: 2019-04-30
• Study Completion: 2019-04-30
• Status Verified: 2019-05
• Last Update Submitted: 2019-05-29
• Last Update Posted: 2019-05-30

Recruitment & Eligibility

• Status: COMPLETED
• Sex: Male
• Target Recruitment: 10

Inclusion Criteria

• recreationally active (no more than 3 hours of weekly physical activity)
• not currently involved in a systematic training program
• body mass index < 30 kg/m2

Exclusion Criteria

• presence of cardiometabolic disease
• taking regular oral medication
• current smoker

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Primary Outcome Measures

Name	Time	Method
Peroxisome proliferator activated receptor gamma co-activator 1-alpha (PGC-1α) messenger ribonucleic acid (mRNA) expression	15 min before fast; after 4 and 8 hours of fasting	PGC-1α gene expression (indirect indicator of PGC-1α activity)

Secondary Outcome Measures

Name	Time	Method
phosphorylated protein kinase A (PKA) substrates	15 min before fast; after 4 and 8 hours of fasting	phosphorylated PKA substrates (indirect measure of PKA activity)
Catecholamine concentrations	15 min before fast; after exercise; after 4 and 8 hours of fasting	Epinephrine and norepinephrine concentrations in plasma samples
total and phosphorylated AMP activated protein kinase (AMPK)	15 min before fast; after 4 and 8 hours of fasting	active AMPK relative to total AMPK protein content
total and phosphorylated SIRT-1	15 min before fast; after 4 and 8 hours of fasting	active SIRT-1 relative to total SIRT1 protein content
total and phosphorylated Akt/Protein Kinase B	15 min before fast; after 4 and 8 hours of fasting	active Akt relative to total Akt protein content
total and phosphorylated p38 mitogen activated protein kinase (MAPK)	15 min before fast; after 4 and 8 hours of fasting	active p38 MAPK relative to total p38 MAPK protein
General control non-repressible 5 (GCN5) mRNA expression	15 min before fast; after 4 and 8 hours of fasting	gene expression of the acetyltransferase GCN5
PGC-1α protein content	15 min before fast; after 4 and 8 hours of fasting	Protein content of the transcriptional co-activator PGC-1α
Intramuscular triglyceride (IMTG) content	15 min before fast; after 4 and 8 hours of fasting	Muscle IMTG content
Glucose and insulin concentrations	15 min before fast; after 4 and 8 hours of fasting	Glucose and insulin concentrations in plasma samples
total and phosphorylated mammalian target of rapamycin (mTOR)	15 min before fast; after 4 and 8 hours of fasting	active mTOR relative to total mTOR protein content
total and phosphorylated acetyl coenzyme A carboxylase (ACC)	15 min before fast; after 4 and 8 hours of fasting	active ACC relative to total ACC protein
Pyruvate dehydrogenase kinase isoenzyme 4 (PDK4) mRNA expression	15 min before fast; after 4 and 8 hours of fasting	gene expression of the PGC-1α target PDK4
p53 mRNA expression	15 min before fast; after 4 and 8 hours of fasting	gene expression of the tumour suppressor protein p53
Leucine rich pentatricopeptide repeat containing protein (LRP130) mRNA expression	15 min before fast; after 4 and 8 hours of fasting	gene expression of RNA-binding protein LRP130
acetylated p53	15 min before fast; after 4 and 8 hours of fasting	p53 acetylation status (indirect measure of SIRT-1 deacetylase activity)
Sirtuin 1 (SIRT1) mRNA expression	15 min before fast; after 4 and 8 hours of fasting	gene expression of the deacetylase enzyme SIRT1
Intramuscular glycogen content	15 min before fast; after 4 and 8 hours of fasting	Muscle glycogen content
Sirtuin 3 (SIRT3) mRNA expression	15 min before fast; after 4 and 8 hours of fasting	gene expression of the deacetylase enzyme SIRT3
Cytochrome C oxidase subunit 4 (COX-IV) protein content	15 min before fast; after 4 and 8 hours of fasting	Protein content of the mitochondrial enzyme COX subunit 4

Trial Locations

Locations (1)

School of Kinesiology and Health Studies; 🇨🇦 Kingston, Ontario, Canada