Backpack Weight Impacts

Backpack Weight Impacts on Perceived Exertion and Heart Rate Variability

Backpacking is an increasingly popular outdoor recreational activity. The base pack weight (BPW) includes gear that is not consumed or worn on the body: shelter, sleep system, weather-proofing layers and personal gear to ensure a degree of comfort and safety. As such, reducing BPW is one of the most important tasks a backpacker manages when preparing for a trip. Available recommendations for ideal BPW are currently inconsistent, lack clear parameters, and rely on anecdotal evidence. The study aims to collect field data on perceived exertion and heart rate (HR) in relation to BPW during a day-long interval of hiking. Such findings can have implications on the cost and safety profiles extending from recreational backpacking to military and wilderness rescue operations.

Study Overview

• Status: Completed
• Conditions: Exertion; Excess
• Intervention / Treatment: Behavioral: The Borg Rating of Perceived Exertion

• Study Type: Interventional
• Enrollment (Actual): 20
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • California
    • Fresno, California, United States, 93703
      • UCSF Fresno

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 65 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Only adult (age 18-65)
• Have gone on at least two overnight backpacking trips in the past 5 years
• Have hiked at least 8 miles in a day on one of those trips

Exclusion Criteria:

• Lower extremity injuries or surgeries in the past 6-months
• Daily Smokers
• Chronic medical problems:
• Hypertension
• High cholesterol
• Diabetes
• Heart attack
• Heart surgery, cardiac catheterization, or coronary angioplasty
• Pacemaker/implantable cardiac defibrillator/rhythm disturbance
• Heart valve disease
• Heart failure
• Heart transplantation
• Congenital heart disease
• Kidney disease
• Back pain

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Supportive Care
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: The Borg Rating of Perceived Exertion between 17 and 19 lb BPW; Participants will be randomized to both 17 and 19 pounds for the first hike and the alternate condition for the second hike. A random number generator will create 1 block that includes 10 participants in each block to ensure comparable numbers to subjects starting at different base backpack weight. Participants assignments will then be included in a sealed manila envelopes.	Behavioral: The Borg Rating of Perceived Exertion; Participants who satisfy the exclusion criteria and health assessment instrument are categorized in the lowest risk group for cardiac events and does not require medical screening for mild to moderate exercise per ACSM guidelines.
Active Comparator: The Borg Rating of Perceived Exertion between 19 and 17 lb BPW; Participants will be randomized to both 19 or 17 pounds for the first hike and the alternate condition for the second hike. A random number generator will create 1 block that includes 10 participants in each block to ensure comparable numbers to subjects starting at different base backpack weight. Participants assignments will then be included in a sealed manila envelopes.	Behavioral: The Borg Rating of Perceived Exertion; Participants who satisfy the exclusion criteria and health assessment instrument are categorized in the lowest risk group for cardiac events and does not require medical screening for mild to moderate exercise per ACSM guidelines.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The Borg Rating of Perceived Exertion During the Total Hike	Participants will report their perceived exertion towards the end of both hikes. The Borg Rating of Perceived Exertion scale ranges from 6 to 20. 6 being the lowest score of no exertion and 20 being the highest of maximal exertion.	2 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Heart Rate	Difference between participants' heart rate during both 17 and 19 pound base backpack weight.	2 weeks
The Borg Rating of Perceived Exertion During Incline and Decline Sections of the participant	Participants will report the perceived exertion mid-hike and towards the end. The Borg Rating of Perceived Exertion scale ranges from 6 to 20. 6 being the lowest score of no exertion and 20 being the highest of maximal exertion.	2 weeks

Collaborators and Investigators

• Sponsor: University of California, San Francisco
• Investigators: Principal Investigator: Susanne Spano, MD, University of California, San Francisco

Study record dates

Study Major Dates

• Study Start (Actual): February 21, 2020
• Primary Completion (Actual): July 1, 2024
• Study Completion (Actual): July 1, 2024

Study Registration Dates

• First Submitted: January 24, 2020
• First Submitted That Met QC Criteria: January 28, 2020
• First Posted (Actual): January 31, 2020

Study Record Updates

• Last Update Posted (Actual): August 5, 2024
• Last Update Submitted That Met QC Criteria: August 1, 2024
• Last Verified: August 1, 2024

More Information

Terms related to this study

• Other Study ID Numbers: 2019126

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No