Fitness and Longevity in Exercise (FLEX)

University of Maryland Baltimore (UMB)

Status: Completed

Conditions: Aging; HIV-1-infection

Treatments: Behavioral: Exercise training

Study type: Interventional

Funder types: Other

Identifiers

NCT03399136

HP-00042601

Details and patient eligibility

About

The study objective was to determine the safety and efficacy of aerobic exercise in older HIV-infected men in a randomized trial comparing different levels of exercise intensity.

Full description

The study was a randomized trial of moderate-intensity versus high-intensity aerobic exercise (AEX) training in older HIV-infected adults. Funding was provided by K23 AG024896 (PI, Oursler) and the UMB Claude D. Pepper Older Americans Independence Center P60 AG12583 (PI, Goldberg).

The central hypothesis was that high-intensity AEX training is well-tolerated and significantly increases aerobic capacity in older HIV-infected adults.

The study met its objectives:

1. Scientific AIMS met:

   1. High-intensity AEX training significantly increases aerobic capacity
   2. Both moderate-intensity and high-intensity AEX training improve ambulatory function and endurance.
   3. Activity of skeletal muscle oxidative enzymes is reduced, and associated with aerobic capacity.

2. Feasibility Objectives met:

   1. AEX training is safe and well-tolerated in older HIV-infected adults.
   2. Skeletal muscle punch biopsy is safe and well-tolerated in older HIV-infected adults.
   3. Preliminary data was collected on plasma biomarkers of inflammation.

Enrollment: 31 patients

Sex: All

Ages: 50+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• HIV+
• stable combination antiretroviral therapy (cART)

Exclusion criteria

• AIDS defining conditions in the prior six months
• Conditions that increase the risk of exercise training per the American College of Sports Medicine (ACSM)

Trial design

Primary purpose: Other

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Double Blind

---

31 participants in 2 patient groups

Moderate-intensity aerobic exercise

Experimental group

Description:

In the moderate-intensity aerobic exercise group, participants performed a self-paced 1-mile walk (3-5 METs) on an indoor track in the same exercise center as the high-intensity exercise group. Initial sessions lasted 20-30 minutes and were increased weekly to 45 minutes in parallel to the duration of the high-intensity exercise group.

Treatment:

Behavioral: Exercise training

High-intensity aerobic exercise

Experimental group

Description:

In the high-intensity aerobic exercise group, exercise training was performed on a motorized treadmill with occasional substitution with the elliptical machine as needed for joint pain. Target heart rate was based on the baseline treadmill test and was calculated as percentage of the heart rate reserve (HRR=maximal HR-resting HR). Initially, participants trained for 20-30 minutes at 50-60% of HRR. Duration and intensity was increased by 10% weekly so that within 5-7 weeks the aerobic exercise sessions lasted 30-45 minutes at 70-85% of HRR and at the end of the 16 weeks lasted 40-45 minutes at 75-90% of HRR.

Treatment:

Behavioral: Exercise training