Heat Therapy and Muscle Function Study

NCT04733287 | Unknown DMC

• 1 other identifier: F2020-023
• Study Type: interventional
• Target: 148
• Locations: 1 country
• Sites: 1

Brief Summary

Exercise tolerance decreases with age and a sedentary lifestyle. Muscle critical power (CP), is a sensitive measure of exercise tolerance that is more even more relevant to and predictive of endurance performance than VO2max. While recent evidence indicates that CP and muscle function decrease with aging, the cause of this decrease in CP and the best way to mitigate the decrease in CP are unknown. This study will:

1. 1.Measure knee extensor CP in young and old individuals and determine the extent to which changes in muscle oxygen delivery (e.g. resistance artery function, maximum exercise blood flow), muscle mass and composition (e.g. whole-muscle size, muscle fiber cross-sectional area) and mitochondrial oxygen consumption (e.g. maximal coupled respiration of permeabilized fibers biopsied from the knee extensors) contribute to the decrease in CP with age.
2. 2.Examine the effectiveness of two different therapies (1. High Intensity Interval Training, HIIT and 2. Muscle Heat Therapy) at improving muscle function and critical power in young and older adults.
3. 3.Examine the impact of muscle disuse (2 weeks of leg immobilization), a potential contributor to the decrease in muscle function with aging, on muscle function and critical power and determine if heat therapy is an effective means of minimizing the impact of disuse on muscle function and critical power.

Conditions

Exercise Intolerance; Aging; Heat Therapy; High Intensity Interval Training

Outcome Measures

Primary Outcomes (1)

• Muscle Critical Power

  Muscle exercise tolerance, quantified as critical power, will be assessed before and after each intervention. The main outcome will be the change in critical power, expressed in Watts, elicited by each intervention. Specifically, participants will perform 3-5 different power outputs of single leg knee extension exercise as long as they can. Subsequently, the line of best fit between the total work performed and duration of each power output trial will be used to quantify critical power, expressed in Watts.

  3-8 weeks

Secondary Outcomes (5)

• Resistance Artery Function

  3-8 weeks

• Maximum Exercise Blood Flow

  3-8 weeks

• Muscle Fiber Size

  3-8 weeks

• Muscle Mitochondrial Function

  3-8 weeks

• Vastus Lateralis Cross-Sectional Area

  3-8 weeks

Study Arms (5)

Effect of High Intensity Interval Training

EXPERIMENTAL

Young and older subjects will participate in single-leg, high-intensity interval training of the right knee extensors (4 intervals of 4 minutes at 80% of max aerobic power with 4 minute rest intervals between, 3x per week for 6 weeks). Muscle function and knee extensor critical power will be measured before and after the 6 weeks of treatment.

Other: High Intensity Interval Training of the Knee Extensors

Effect of Muscle Heat Therapy

EXPERIMENTAL

Young and older subjects will participate in single-leg,heat therapy training of a single leg ( quadriceps femoris, 120 minutes of shortwave diathermy to raise the muscle temperature to \~39C) 3 times a week for 6 weeks. Muscle function and knee extensor critical power will be measured before and after the 6 weeks of treatment.

Other: Muscle Heat Therapy

Effect of Sham Muscle Heat Therapy

SHAM COMPARATOR

Young and older subjects will participate in a sham treatment of single-leg,heat therapy training of the right knee extensors (120 minutes with shortwave diathermy unit positioned on leg, but not turned on) 3 times a week for 6 weeks. Muscle function and knee extensor critical power will be measured before and after the 6 weeks of treatment.

Other: Sham Heat Therapy

Effect of Immobilization with Daily Sham Heat Therapy

SHAM COMPARATOR

Young subjects (18-35 years) will undergo 2 weeks of leg immobilization while receiving 2 hours of a sham heat therapy treatment each day. For the sham treatment, the heating device will be applied to the limb, but, unbeknownst to the participant, it will not be turned on. Muscle function and knee extensor critical power will be measured before and after the 2 weeks of leg immobilization.

Other: Sham Heat Therapy

Effect of Immobilization with Daily Heat Therapy

EXPERIMENTAL

Young subjects (18-35 years) will undergo 2 weeks of leg immobilization while receiving 2 hours of heat therapy treatment each day. Heat therapy will consist of 120 minutes of shortwave diathermy to raise the quadriceps femoris muscle temperature to \~39C. Muscle function and knee extensor critical power will be measured before and after the 2 weeks of leg immobilization.

Other: Muscle Disuse

Interventions

High Intensity Interval Training of the Knee Extensors OTHER

Subjects will perform intense, single leg knee extension exercise 3 times a week for 6 weeks. Specifically, subjects will be seated in a custom knee extension ergometer and perform single leg, dynamic knee extension (similar to single leg cycling) as they perform the exercise. After a 6 minute warm-up at \~20% of that leg's maximum aerobic power (determined during a graded exercise test of single leg knee extension), subjects will perform 4 bouts of 4 minutes at \~80% of maximum aerobic power. Recovery of 4 minutes at \~40% will occur between each bout of exercise. A cool down will be provided at the end of exercise. In total, subjects will perform 40 minutes of single leg knee extension exercise, 3 times a week for 6 weeks. Maximum aerobic power (determined by a graded exercise test) will be determined again at 3 weeks to appropriately adjust the training intensity.

Also known as: HIIT

Effect of High Intensity Interval Training

Muscle Heat Therapy OTHER

Subjects will receive muscle heat therapy on the knee extensor muscles (short-wave diathermy) for 120 minutes for each visit. Specifically, subjects will lie supine while short-wave diathermy units (Megapulse II) will be placed on the quadriceps femoris and turned on to 800 pulses per second with a pulse duration of 400 microseconds. Our previous research (e.g. Hafen et al 2018- Repeated exposure to heat stress...) has indicated that this treatment raises muscle temperature to \~39C, a similar temperature induced by exercise.

Also known as: Short-wave Diathermy

Effect of Muscle Heat Therapy

Muscle Disuse OTHER

Subjects will undergo 2 weeks of limb immobilization (a model of muscle disuse). Specifically, a knee brace will be placed on one of the subjects' legs and bent to a flexion of 60 degrees to prevent the foot from touching the ground while standing. Subjects will given a pair of crutches and asked to ambulate on crutches for 2 weeks, avoiding bearing any weight with the immobilized leg.

Also known as: Leg Immobilization

Effect of Immobilization with Daily Heat Therapy

Sham Heat Therapy OTHER

Specifically, subjects randomly assigned to the sham group will receive the same treatment as the heat group (same number of visits and set up with the heating units applied to leg for 2 hours each visit) except, unbeknownst to either group, the heating units will never be turned on for the sham group.

Effect of Immobilization with Daily Sham Heat Therapy; Effect of Sham Muscle Heat Therapy

Eligibility Criteria

• Age: 18 Years - 95 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• years of age
• Currently no cardiovascular or metabolic disease (e.g. heart failure, diabetes)
• ability to perform knee extension exercise

You may not qualify if:

• Pregnant
• Current cardiovascular or metabolic disease (e.g. heart failure, diabetes)
• participating in exercise training within the last 6 months
• inability to perform knee extension exercise

Sponsors & Collaborators

• Brigham Young University: lead

Study Sites (1)

Brigham Young University

Provo, Utah, 84602, United States

RECRUITING

Related Publications (10)

• Gifford JR, Richardson RS. CORP: Ultrasound assessment of vascular function with the passive leg movement technique. J Appl Physiol (1985). 2017 Dec 1;123(6):1708-1720. doi: 10.1152/japplphysiol.00557.2017. Epub 2017 Sep 7.

  PMID: 28883048 BACKGROUND

• Park SY, Ives SJ, Gifford JR, Andtbacka RH, Hyngstrom JR, Reese V, Layec G, Bharath LP, Symons JD, Richardson RS. Impact of age on the vasodilatory function of human skeletal muscle feed arteries. Am J Physiol Heart Circ Physiol. 2016 Jan 15;310(2):H217-25. doi: 10.1152/ajpheart.00716.2015. Epub 2015 Nov 20.

  PMID: 26589330 BACKGROUND

• Gifford JR, Garten RS, Nelson AD, Trinity JD, Layec G, Witman MA, Weavil JC, Mangum T, Hart C, Etheredge C, Jessop J, Bledsoe A, Morgan DE, Wray DW, Rossman MJ, Richardson RS. Symmorphosis and skeletal muscle V̇O2 max : in vivo and in vitro measures reveal differing constraints in the exercise-trained and untrained human. J Physiol. 2016 Mar 15;594(6):1741-51. doi: 10.1113/JP271229. Epub 2016 Jan 19.

  PMID: 26614395 BACKGROUND

• Hanson BE, Proffit M, Gifford JR. Vascular function is related to blood flow during high-intensity, but not low-intensity, knee extension exercise. J Appl Physiol (1985). 2020 Mar 1;128(3):698-708. doi: 10.1152/japplphysiol.00671.2019. Epub 2020 Jan 9.

  PMID: 31917628 BACKGROUND

• Hafen PS, Preece CN, Sorensen JR, Hancock CR, Hyldahl RD. Repeated exposure to heat stress induces mitochondrial adaptation in human skeletal muscle. J Appl Physiol (1985). 2018 Nov 1;125(5):1447-1455. doi: 10.1152/japplphysiol.00383.2018. Epub 2018 Jul 19.

  PMID: 30024339 BACKGROUND

• Hafen PS, Abbott K, Bowden J, Lopiano R, Hancock CR, Hyldahl RD. Daily heat treatment maintains mitochondrial function and attenuates atrophy in human skeletal muscle subjected to immobilization. J Appl Physiol (1985). 2019 Jul 1;127(1):47-57. doi: 10.1152/japplphysiol.01098.2018. Epub 2019 May 2.

  PMID: 31046520 BACKGROUND

• Poole DC, Burnley M, Vanhatalo A, Rossiter HB, Jones AM. Critical Power: An Important Fatigue Threshold in Exercise Physiology. Med Sci Sports Exerc. 2016 Nov;48(11):2320-2334. doi: 10.1249/MSS.0000000000000939.

  PMID: 27031742 BACKGROUND

• Helgerud J, Hoydal K, Wang E, Karlsen T, Berg P, Bjerkaas M, Simonsen T, Helgesen C, Hjorth N, Bach R, Hoff J. Aerobic high-intensity intervals improve VO2max more than moderate training. Med Sci Sports Exerc. 2007 Apr;39(4):665-71. doi: 10.1249/mss.0b013e3180304570.

  PMID: 17414804 BACKGROUND

• Brunt VE, Howard MJ, Francisco MA, Ely BR, Minson CT. Passive heat therapy improves endothelial function, arterial stiffness and blood pressure in sedentary humans. J Physiol. 2016 Sep 15;594(18):5329-42. doi: 10.1113/JP272453. Epub 2016 Jun 30.

  PMID: 27270841 BACKGROUND

• Kim K, Reid BA, Casey CA, Bender BE, Ro B, Song Q, Trewin AJ, Petersen AC, Kuang S, Gavin TP, Roseguini BT. Effects of repeated local heat therapy on skeletal muscle structure and function in humans. J Appl Physiol (1985). 2020 Mar 1;128(3):483-492. doi: 10.1152/japplphysiol.00701.2019. Epub 2020 Jan 23.

  PMID: 31971474 BACKGROUND

MeSH Terms

Conditions

Hyperthermia

Condition Hierarchy (Ancestors)

Body Temperature Changes; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Heat Stress Disorders; Wounds and Injuries

Study Officials

• Jayson Gifford, Ph.D.

  Brigham Young University

  STUDY DIRECTOR

• Robert Hyldahl, Ph.D.

  Brigham Young Univeristy

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Jayson Gifford, Ph.D.

CONTACT

8014223090; jaysongifford@byu.edu

Robert Hyldahl, Ph.D.

CONTACT

8014223090; robhyldahl@byu.edu

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: PARTICIPANT
• Masking Details: Subjects assigned to the heat therapy and the sham heat therapy will not know if they are truly receiving the heat therapy or not. The muscle heater (shortwave diathermy) will be placed on the muscle during each visit, but, unbeknownst to the heat and sham group, will not be turned on for the sham group.
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Assistant Professor

Model Details: Young (18-35 years) and Older (60+ years) will be randomly assigned to one of 3 different conditions (High Intensity Exercise Training of the Knee Extensors, Heat therapy of the Knee Extensors or Sham Heat therapy of the Knee Extensors). Muscle function will be measured before and after 6 weeks of the randomized treatment. A separate set of 40 young adults (18-35 years) will undergo 2 weeks of leg immobilization. Half of the subjects will receive daily heat therapy, while the other half will receive a sham heat therapy treatment. Muscle function and critical power will be measured before and after immobilization for both groups

Study Record Dates

• First Submitted: October 14, 2020
• First Posted: February 2, 2021
• Study Start: April 1, 2021
• Primary Completion: December 31, 2024
• Study Completion: December 31, 2024
• Last Updated: February 2, 2021

Record last verified: 2021-01

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)