Phase 4 N=12 Randomized Basic Science

The Influence of Menthol Gel During Exercise With Heat

Acute Exercise · Heat Exposure

Bottom Line

View on ClinicalTrials.gov: NCT05302804 ↗

Enrolled (actual)

Serious AEs

0.0%

Results posted

Apr 2024

Primary outcome: Primary: Skin Blood Flow — 131.6; 119.2 arbitrary units — p=0.742

Study Design & Population

Study type: Interventional
Phase: Phase 4
Interventions: Menthol Gel (Drug); Control Gel (Drug)
Age: Adult · 19+ yrs
Sex: All
Sponsor: University of Nebraska
Primary completion: Oct 2022

Outcome Measures

Outcome	Result	p-value
PRIMARY Skin Blood Flow	196.1; 194.8	0.742
PRIMARY Skin Blood Flow	196.1; 194.8	0.742
PRIMARY Galvanic Skin Response	1299; 1148	0.048 sig
PRIMARY Sweat Composition	38.9; 43.9	.104
PRIMARY Sweat Rate	1.1; 1.3	.051
PRIMARY Thermal Perception	0.7; 1.8	< 0.001 sig
PRIMARY Average Skin Temperature	37.6; 37.2	.026 sig
PRIMARY Core Temperature	38.1; 37.7	.001 sig
PRIMARY Sweat Potassium Concentration	7.1; 6.9	>0.05
SECONDARY % Body Fat	20.1	—
SECONDARY Skin Surface Area	1.98	—

Summary

The purpose of this study is to examine the human thermoregulatory impact of applying a commercially available menthol gel (BioFreeze) to the skin prior to moderate intensity walking under heated conditions. Experimental Visits will consist of 30 min of treadmill walking at a moderate pace (3.5 mph, 5% grade) under hot conditions (38°C, 60%RH) and will be randomized and counterbalanced for BioFreeze or a hypoallergenic gel (control) application. Gels will be applied to areas commonly exposed during outdoor activity in warm conditions (shoulder to wrist, mid thigh to ankle). Accordingly, participants will wear shorts and a tank top shirt during exercise. Core temperature, skin temperature, galvanic skin response, laser doppler blood flow, and heart rate will be continuously recorded throughout the exercise bout via an integrated analog to digital converter. Sweat will be collected during exercise using commercially available absorbent patches. Thermal sensation will be assessed throughout exercise via the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) thermal sensation likert scale (cold to hot). Lastly, nude body weight will be recorded pre and post exercise for sweat rate determination. The BioFreeze and control trials will be separated by a 7-14 day washout period.

Eligibility Criteria

Inclusion Criteria

19-45 years of age
cleared for physical activity via the 2022 physical activity readiness questionnaire (PARQ)
no self-reported adverse reactions to menthol based gels

Exclusion Criteria

outside 19-45 years of age
not cleared for physical activity via the 2022 physical activity readiness questionnaire (PARQ)
self-report or signs of sensitivity to menthol gels
pregnant
breast feeding

View full record on ClinicalTrials.gov →

Data sourced from ClinicalTrials.gov (NCT05302804). Outcome figures and adverse-event rates are extracted automatically from the registry's posted results and are provided for clinician reference, not as a substitute for the primary publication.