Muscle Capillarization and Sarcopenia

Increasing Muscle Capillarization to Enhance Responses to Strength Training in Sarcopenia

Aging is associated with a loss of muscle mass, termed sarcopenia, that reduces mobility, decreases physical function and accelerates progression of other age-related disorders. This study is designed to determine whether increasing skeletal muscle capillarization through aerobic exercise will enhance muscular adaptations to strength training in older adults with sarcopenia.

Study Overview

• Status: Completed
• Conditions: Sarcopenia
• Intervention / Treatment: Other: Aerobic exercise training; Other: Strength training

Detailed Description

Sarcopenia, or the aging-related loss of muscle mass, affects a large number of older adults. The presence of sarcopenia is associated with physical disability, poor quality of life, and all-cause mortality, in part because sarcopenic adults have low muscle skeletal muscle capillarization and may lack the adequate perfusion needed to maintain muscle mass and function. This study will test the effects of increasing skeletal muscle capillarization through aerobic exercise training on responses to resistance training in older adults. Eligible participants will be randomized to one of two groups, resistance training preceded by aerobic exercise training (AEX-RT), or resistance training followed by aerobic exercise training (RT-AEX). Participants in the AEX-RT group will undergo 3 months of aerobic exercise training to increase skeletal muscle capillarization, followed by 3 months of resistance training. Participants in the RT-AEX group will undergo 3 months of resistance training, followed by 3 months of aerobic exercise training. Before and after the interventions, participants will undergo assessments of muscle size, strength, and capillarization, as well as assessments of physical function.

• Study Type: Interventional
• Enrollment (Actual): 14
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Maryland
    • Baltimore, Maryland, United States, 21201
      • University of Maryland, Baltimore & Baltimore VA Medical Center
    • College Park, Maryland, United States, 20742
      • University of Maryland

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 65 years to 88 years (Older Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Body Mass Index = 18-32.5 kg/m2
• Non-smoker
• Presence of at least moderate sarcopenia (low muscle mass per unit body height)

Exclusion Criteria:

• Diagnosis of diabetes, cancer, pulmonary or renal disease
• Physical impairment preventing exercise
• Recent history of exercise training

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Aerobic exercise training followed by resistance training; Participants in this arm will undergo 3 months of aerobic exercise training, followed by 3 months of strength training	Other: Aerobic exercise training; 3 months of center-based, supervised treadmill exercise; Other: Strength training; 3 months of center-based, supervise strength training
Active Comparator: Resistance training followed by aerobic exercise training; Participants in this arm will undergo 3 months of strength training, followed by 3 months of aerobic exercise training	Other: Aerobic exercise training; 3 months of center-based, supervised treadmill exercise; Other: Strength training; 3 months of center-based, supervise strength training

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Skeletal Muscle Capillarization	Change in the number of capillaries per unit of skeletal muscle tissue after resistance training. The aims of the study were to compare responses to resistance training between arms/groups. Therefore, only the resistance training-induced change (post minus pre-resistance training) is assessed and analyzed as this is the primary outcome for each arm.	3 months (post minus pre-resistance training)
Quadriceps Muscle Cross-sectional Area	Change in the size of the thigh muscles. The aims of the study were to compare responses to resistance training between arms/groups. Therefore, only the resistance training-induced change (post minus pre-resistance training) is assessed and analyzed as this is the primary outcome for each arm.	3 months (post minus pre-resistance training)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Skeletal Muscle Fiber Size	Change in the cross-sectional size of individual thigh skeletal muscle fibers. The aims of the study were to compare responses to resistance training between arms/groups. Therefore, only the resistance training-induced change (post minus pre-resistance training) is assessed and analyzed as this is the primary outcome for each arm.	3 months (post minus pre-resistance training)
Muscle Strength	Change in the strength/force produced by skeletal muscles of the thigh. Only the resistance training-induced change (post minus pre-resistance training) is reported as this is the primary outcome for each arm.	3 months (post minus pre-resistance training)

Collaborators and Investigators

• Sponsor: Baltimore VA Medical Center
• Collaborators: University of Maryland, Baltimore; National Institute on Aging (NIA)

Study record dates

Study Major Dates

• Study Start (Actual): November 1, 2021
• Primary Completion (Actual): April 30, 2024
• Study Completion (Actual): April 30, 2024

Study Registration Dates

• First Submitted: June 5, 2019
• First Submitted That Met QC Criteria: June 12, 2019
• First Posted (Actual): June 13, 2019

Study Record Updates

• Last Update Posted (Estimated): October 29, 2025
• Last Update Submitted That Met QC Criteria: October 15, 2025
• Last Verified: October 1, 2025

More Information

Terms related to this study

• Keywords: exercise; muscle; capillary
• Additional Relevant MeSH Terms: Neurologic Manifestations; Nervous System Diseases; Neuromuscular Manifestations; Pathological Conditions, Anatomical; Muscular Atrophy; Atrophy; Pathological Conditions, Signs and Symptoms; Behavior; Signs and Symptoms; Sarcopenia; Motor Activity; Motor Activity; Movement; Musculoskeletal Physiological Phenomena; Musculoskeletal and Neural Physiological Phenomena; Therapeutics; Physical Therapy Modalities; Patient Care; Exercise Therapy; Rehabilitation; Aftercare; Continuity of Patient Care; Physical Conditioning, Human; Exercise; Resistance Training
• Other Study ID Numbers: HP-00086001; 5R21AG064571 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

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