Muscle and Body Temperature Responses During Uphill and Downhill Running

Summary

In animal models of thermoregulation (how the body regulates heat), heat-sensitive nerve cells that help regulate body temperature have been identified throughout the body (e.g. in muscles, viscera, and blood vessels, among others); however, in human thermoregulation models, only two locations are generally recognized: the core (brain) and the skin. The limited number of recognized locations in humans are likely due to the difficulty in testing these locations in humans, as these locations are typically identified in animals by sedating them, surgically opening them up, stimulating the area of interest with a hot or cold probe, and then measure thermoregulatory responses.

Based on the literature, the researchers believe that by having participants run at the same energy expenditure but at three different inclines (uphill, downhill and flat) on a treadmill, the researchers can independently alter muscle temperature, while keeping core and skin temperature the same. Additionally, recent studies have suggested that temperature has a greater role at regulating blood flow through muscle tissue than previously recognized. Because of this, the researchers aim to have a second arm of the study to see whether these differences in muscle temperature result in differences in post-exercise blood flow to the muscle.

Finally, downhill running is often used to study exercise-induced muscle damage, due to the greater breaking forces compared to flat land running. Because of this, a third study aim will be to examine the association between fitness level, body morphology and sex on exercise-induced muscle damage.

Conditions

• Body Temperature Changes
• Exercise
• Blood Pressure

Interventions

PROCEDURE

Uphill running

Participants will run at 70% of their maximal oxygen consumption for 60 min at a 10 degree (17.6%) incline.

PROCEDURE

Flatland running

Participants will run at 70% of their maximal oxygen consumption for 60 min at a 0 degree (0%) incline.

PROCEDURE

Downhill running

Participants will run at 70% of their maximal oxygen consumption for 60 min at a -10 degree (-17.6%) decline.

Sponsors & Collaborators

• University of Colorado, Colorado Springs

  collaborator OTHER

• CommonSpirit Health

  lead OTHER

Principal Investigators

• Nathan B Morris, PhD · University of Colorado, Colorado Springs

Study Design

Allocation

RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

NONE

Model

CROSSOVER

Eligibility

Min Age

18 Years

Max Age

45 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2024-12-01

Primary Completion

2025-12-31

Completion

2026-12-31