What is the Role of Type III/IV Muscle Afferents in Airway Resistance and Thermoregulatory Responses to Exercise?

NCT07452094 | Not Yet Recruiting Early Phase 1 FDA Drug

• 1 other identifier: 2357749
• Study Type: interventional
• Target: 15
• Locations: 1 country
• Sites: 1

Brief Summary

Exercise places serious demands on the body. These demands are fundamentally caused by increases in oxygen demand and the consequent increase in body temperature. These demands are met by several physiological responses, including increases in heart rate, blood pressure, breathing and blood flow. These responses must be proportional to the increase in demand and some signal must relay information from the muscle to the brain. Group III/IV afferents do just this. They relay information about the muscle (movement, temperature, acidity, etc.) up to the brain so that appropriate responses are mounted. There is strong evidence in animals that group III/IV afferents play a key role in making breathing easier (decreasing airway resistance) and initiating sweating and blood flow responses. There has been no research on the role of group III/IV afferents on these fundamental exercise responses in humans. The investigators propose to isolate the role of group III/IV afferents on regulate airway resistance, sweating and blood flow responses to exercise in humans.

Conditions

Placebo - Control; Experimental

Keywords

Group III/IV afferents; exercise; thermoregulation; sweating; blood flow; airway resistance

Outcome Measures

Primary Outcomes (3)

• Airway resistance

  Calculated based of work of breathing and ventilation flow rate

  2 weeks

• Sweat rate

  Local eccrine sweat rates at 3 different sites

  2 weeks

• Skin blood flow

  Skin blood flux measured at different skin sites

  2 weeks

Study Arms (2)

Placebo-control

PLACEBO COMPARATOR

Exercise with saline injection

Drug: EXERCISE TRAINING WITH OR WITHOUT MEDICATION

Group III/IV afferent blockade

EXPERIMENTAL

Feedback from group III/IV afferents is blocked

Drug: EXERCISE TRAINING WITH OR WITHOUT MEDICATION

Interventions

EXERCISE TRAINING WITH OR WITHOUT MEDICATION DRUG

Cycling exercise with group III/IV afferent feedback blocked via drug

Group III/IV afferent blockade; Placebo-control

Eligibility Criteria

• Age: 18 Years - 40 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• regularly physically active as determined via questionnaires (Par-Q \& You)
• maximal aerobic power 30 mL/min/kg (female), 40 mL/kg/min (male)

You may not qualify if:

• current smokers
• acute bronchial asthma
• diabetics
• chronic back pain
• peripheral neuropathy
• chronic obstructive airway or status asthmaticus
• obese (body mass index \> 30 kg/m2)
• convulsive disorders
• requiring daily medications that may affect responses to exercise (e.g. anti-hypertensive, anti-arrhythmogenics, blood thinners)
• history of drug abuse
• history of disease/dysfunction that could cause complication with exercise (e.g. cardiovascular, respiratory, neurological, musculoskeletal)
• irregular or absent menstrual cycle
• pregnant or suspected pregnancy
• adverse response to physical exercise
• current or history of esophageal or gastric disease, or frequent heart burn (\>2x per week)

Sponsors & Collaborators

• Northern Arizona University: lead

Study Sites (1)

Northern Arizona University

Flagstaff, Arizona, 86011, United States

Location

MeSH Terms

Conditions

Motor Activity

Interventions

Exercise; Dosage Forms

Condition Hierarchy (Ancestors)

Behavior

Intervention Hierarchy (Ancestors)

Motor Activity; Movement; Musculoskeletal Physiological Phenomena; Musculoskeletal and Neural Physiological Phenomena; Pharmaceutical Preparations; Technology, Pharmaceutical; Investigative Techniques

Study Officials

• TRAVIS D GIBBONS, PhD

  Northern Arizona University

  PRINCIPAL INVESTIGATOR

Central Study Contacts

TRAVIS D GIBBONS, PhD

CONTACT

19282558769; travis.gibbons@nau.edu

Study Design

• Study Type: interventional
• Phase: early phase 1
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
• Masking Details: Participant will be blinded to condition. Researcher will be blinded to condition. Researcher will be masked to data during analysis.
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: Randomized order, repeated measures, cross-over

Study Record Dates

• First Submitted: December 24, 2025
• First Posted: March 5, 2026
• Study Start: April 1, 2026
• Primary Completion (Estimated): December 31, 2026
• Study Completion (Estimated): April 1, 2027
• Last Updated: March 5, 2026

Record last verified: 2025-12

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)