Heat and Exercise in Aging as Therapy (HEAT)

NCT06580964 | Recruiting DMC

• 1 other identifier: R01AG084597
• Study Type: interventional
• Target: 54
• Locations: 1 country
• Sites: 1

Brief Summary

The main goal of this two-phase clinical trial is to learn whether local heat therapy, using heat pads applied to the legs, can enhance skeletal muscle health, physical function, and blood sugar control in a manner comparable to exercise, specifically High-Intensity Interval Training (HIIT), in older individuals with prediabetes. The study aims to answer the following questions:

1. 1.Does local heat therapy improve muscle architecture (e.g., muscle cross-sectional area, capillary density, mitochondrial content), glucose tolerance, and frailty indicators similarly to HIIT in older individuals with prediabetes?
2. 2.Does local heat therapy as a pre-conditioning method enhance the skeletal muscle response to HIIT in older individuals with prediabetes?

Conditions

Prediabetic State

Keywords

Exercise; Heat; Aging; Prediabetes; Skeletal Muscle

Outcome Measures

Primary Outcomes (5)

• Glycemic control

  Oral glucose tolerance test (OGTT)

  Before intervention, after Phase 1 (at about 12 weeks), and after Phase 2 (at about 24 weeks, except HIIT group)

• Skeletal muscle architecture 1

  Immunohistochemical assessment of muscle fiber cross-sectional area and capillary density

  Before intervention, after Phase 1 (at about 12 weeks), and after Phase 2 (at about 24 weeks, except HIIT group)

• Skeletal muscle architecture 2

  Assessment of skeletal muscle mitochondrial content

  Before intervention, after Phase 1 (at about 12 weeks), and after Phase 2 (at about 24 weeks, except HIIT group)

• Frailty status

  Fried's Phenotypic Frailty assessment

  Before intervention, after Phase 1 (at about 12 weeks), and after Phase 2 (at about 24 weeks, except HIIT group)

• Exercise capacity

  VO2peak testing

  Before intervention, after Phase 1 (at about 12 weeks), and after Phase 2 (at about 24 weeks, except HIIT group)

Secondary Outcomes (4)

• Anthropometrics 1

  Weekly for about 14 (HIIT group) or about 27 (LHT and CON groups) weeks

• Anthropometrics 2

  Weekly for about 14 (HIIT group) or about 27 (LHT and CON groups) weeks

• Body composition

  Before intervention, after Phase 1 (at about 12 weeks), and after Phase 2 (at about 24 weeks, except HIIT group)

• Sleep quality

  Weekly for about 14 (HIIT group) or about 27 (LHT and CON groups) weeks

Study Arms (3)

Local Heat Therapy

EXPERIMENTAL

Phase 1: Heat pads will be applied to both legs and set to a pre-determined, optimized temperature to raise the intramuscular temperature to 3-4°C above resting. Each heating session will last for 90 min/d, 6d/wk (5 at-home and 1 in-lab) for 12 wks. Phase 2: High-intensity interval training will be performed 3 d/wk for 12 wks. Each exercise session will consist of 4 cycling exercise intervals (4 min each) with 3 min active rest between intervals. Interval intensity will progressively increase from 70-75% to 90-95% of VO2peak by the end of week 3.

Behavioral: Heat therapy; Behavioral: High-intensity interval training

Thermoneutral Therapy

SHAM COMPARATOR

Phase 1: Heat pads will be applied to both legs and set to a pre-determined temperature to keep the intramuscular temperature in a thermoneutral state (\~35-37°C). Each heating session will last for 90 min, 7d/wk (6 at-home and 1 in-lab) for 12 weeks. Phase 2: High-intensity interval training will be performed 3 d/wk for 12 wks. Each exercise session will consist of 4 cycling exercise intervals (4 min each) with 3 min active rest between intervals. Interval intensity will progressively increase from 70-75% to 90-95% of VO2peak by the end of week 3.

Behavioral: Heat therapy; Behavioral: High-intensity interval training

High-Intensity Interval Training

ACTIVE COMPARATOR

Phase 1: High-intensity interval training will be performed 3 d/wk for 12 wks. Each exercise session will consist of 4 cycling exercise intervals (4 min each) with 3 min active rest between intervals. Interval intensity will progressively increase from 70-75% to 90-95% of VO2peak by the end of week 3. Phase 2: N/A.

Behavioral: High-intensity interval training

Interventions

Heat therapy BEHAVIORAL

Heat pads will be set to a pre-determined, optimized temperature and applied to both legs for 90 min, 6d/wk (5 at-home and 1 in-lab).

Local Heat Therapy; Thermoneutral Therapy

High-intensity interval training BEHAVIORAL

High-intensity interval training will be performed 3 days per week for 12 weeks.

High-Intensity Interval Training; Local Heat Therapy; Thermoneutral Therapy

Eligibility Criteria

• Age: 50 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Age ≥ 50 years
• Women who are postmenopausal, defined as no menstrual period for at least 12 consecutive months.
• Sedentary (structured exercise \<30 minutes, 3x/week)
• Body weight is at least 110 lbs
• Meet criteria for prediabetes (fasting blood glucose 100-125 mg/dl, hemoglobin A1c 5.7-6.4%)
• Consume \<8 (women) or \<15 (men) alcohol-containing beverages per week
• Do not use nicotine or cannabis
• Not taking any medications that could interfere with responses to the interventions (e.g., corticosteroids, opiates, benzodiazepines, tricyclic antidepressants, beta blockers, sulfonylureas, insulin, metformin, anticoagulants, barbiturates, insulin sensitizers, fibrates, immunosuppressants). If you don't know, that's okay. We'll ask what medications you are on and check whether they fall into one of these categories.

You may not qualify if:

• History of peripheral neuropathies
• Currently taking prescription blood thinners
• Medical complications that could would contraindicate participation in the high intensity interval training (HIIT) intervention including: orthopedic complications that would limit your ability to perform cycling exercise, significant cardiovascular impairments (e.g., history of arrhythmias, severe uncontrolled hypertension, etc.), diagnosed metabolic disease (e.g., diabetes), renal disease, sickle cell anemia, or cancer in remission for \<6 months.
• Known history of slow wound healing
• Lidocaine allergy
• Latex allergy
• Currently pregnant
• \>1.5" subcutaneous fat over the thigh muscle
• Symptoms suggestive of cardiovascular, respiratory, metabolic, or renal diseases including discomfort, pressure, or pain in your chest, neck, jaw, arms, calves, or other areas potentially related to ischemia; shortness of breath at rest or with mild exertion; dizziness or fainting (syncope); difficulty breathing while lying flat (orthopnea) or sudden nighttime breathing difficulties (paroxysmal nocturnal dyspnea); palpitations or rapid heartbeat (tachycardia); pain or cramping in your legs during physical activity (intermittent claudication); a known heart murmur; swelling in your ankles (edema); unusual fatigue or shortness of breath during routine activities or at rest.

Sponsors & Collaborators

• Texas Tech University: lead

Study Sites (1)

Texas Tech University

Lubbock, Texas, 79409, United States

RECRUITING

MeSH Terms

Conditions

Prediabetic State; Motor Activity

Interventions

Diathermy; High-Intensity Interval Training

Condition Hierarchy (Ancestors)

Diabetes Mellitus; Glucose Metabolism Disorders; Metabolic Diseases; Nutritional and Metabolic Diseases; Endocrine System Diseases; Behavior

Intervention Hierarchy (Ancestors)

Hyperthermia, Induced; Therapeutics; Physical Conditioning, Human; Exercise; Motor Activity; Movement; Musculoskeletal Physiological Phenomena; Musculoskeletal and Neural Physiological Phenomena

Study Officials

• Hui-Ying Luk, PhD; Danielle Levitt, PhD

  Texas Tech University

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Hui-Ying Luk, PhD

CONTACT

8068340827; huiying.luk@ttu.edu

Danielle Levitt, PhD

CONTACT

8068341830; danielle.levitt@ttu.edu

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Masking Details: Blinded
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: August 23, 2024
• First Posted: August 30, 2024
• Study Start: July 31, 2025
• Primary Completion (Estimated): July 1, 2028
• Study Completion (Estimated): July 1, 2029
• Last Updated: September 17, 2025

Record last verified: 2025-09

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, ANALYTIC CODE
• Time Frame: Data associated with each publication will be made available when preprints are available and will continue to be available on the repositories and long as they are supported. Any data that are not yet available by the end of the award period will be made available at that time.
• Access Criteria: Requests for data must be submitted through the Aging Research Biobank (see https://agingresearchbiobank.nia.nih.gov/how-to-make-a-request/).

Locations

US (1)