Carrying Heavy Shopping Bags and Muscle Function

NCT07271108 | Completed

• 1 other identifier: 200220195
• Study Type: interventional
• Target: 45
• Locations: 1 country
• Sites: 1

Brief Summary

What Is This Study About? To find out whether carrying heavy shopping bags twice a week can help adults not currently meeting physical activity strength guidelines improve muscle mass, strength, power, and endurance. What Can Be learnt?

• Can carrying shopping bags help improve muscle mass, strength, power, and endurance?
• Should carrying shopping bags be included within physical activity recommendations? Two groups will be compared:
• One group will carry shopping bags twice a week within a controlled lab environment
• The other group won't change anything in their routine. What Will Participants Do?
• Self-select a weight for shopping bags that is heavy but can be carried for 15 minutes to use for all sessions
• Walk with shopping bags for 15 minutes at a normal walking speed for carrying shopping home from the supermarket.
• After each minute, the time stops and participants place bags on the floor. The time restarts for the next minute when the participant chooses to pick up the bags again.

Conditions

Strength; Strength Training Effects; Resistance Exercise

Keywords

Health promotion; Resistance training; strength training; carrying shopping

Outcome Measures

Primary Outcomes (6)

• Back strength

  Takei Back Strength Dynamometer (T.K.K. 5002 BACK-A Type-3) used to measure back strength to the nearest 1 kg. Measurements taken with the legs, back and arms straight and the torso flexed to 30 degrees at the hip with the handle held in a natural grip. Participants instructed to gradually pull as hard as they could on the handle in order to raise the upper part of their body without bending their knees. Three trials performed with the maximum value used in the analysis.

  Baseline and one week after the intervention ended

• Jump Height

  Assessed using a countermovement jump with hands on hips. Participants instructed to crouch into a squat position and then jump as high as possible with legs fully extended and landing on the same spot with knees extended and feet together. After a familiarisation attempt, participants to perform three countermovement jumps and the maximum peak power used in the analysis. Jump height and flight time calculated using Microgate Optojump Next software version 1.10.5.0 connected to photoelectric bars RX10 and TX10 (Microgate Optojump Next, Bolzano, Italy) placed parallel to each other. Jump height derived from the equation: H = g×t2/8 (H = the jump height (m), t = jump flight time (seconds) and g = acceleration due to gravity (9.81 m/s-2))

  Baseline and one week after the intervention ended

• Peak Power

  Assessed using a countermovement jump with hands on hips. Participants instructed to crouch into a squat position and then jump as high as possible with legs fully extended and landing on the same spot with knees extended and feet together. After a familiarisation attempt, participants to perform three countermovement jumps and the maximum peak power used in the analysis. Jump height and flight time calculated using Microgate Optojump Next software version 1.10.5.0 connected to photoelectric bars RX10 and TX10 (Microgate Optojump Next, Bolzano, Italy) placed parallel to each other. Peak Power calculated using the Sayers equation: Peak Power (Watts) = 60.7 × jump height (cm) + 45.3 × body mass (kg) - 2055

  Baseline and one week after the intervention ended

• Muscle Endurance

  Endurance assessed by a 60 second sit to stand test using a 46.5cm high, straight-backed chair with a hard seat and no arm rests. From a seated position with hands on shoulders and arms crossed across the chest, participants instructed to stand up from the chair until their legs were completely straight, then sit back down again (one complete sit to stand) as many times as possible in 60 seconds. The number of complete sit to stands used in the analysis.

  Baseline and one week after the intervention ended

• Grip strength

  Jamar hydraulic hand dynamometer in handle position II used to measure grip strength to the nearest 1 kg. Measurements taken with the participant seated with feet flat on the floor, elbow flexed 90 degrees by their side and with the wrist just over the end of the arm of the chair in a neutral position (thumbs-up position). Participants instructed to squeeze as hard as possible until the needle stopped rising with the verbal encouragement of "squeeze, squeeze, squeeze and relax". Three trials performed on each side, alternately, with the maximum value used in the analysis in accordance with the Southampton protocol

  Baseline and one week after the intervention ended

• Body composition

  Assessed using a Body Composition Analyzer Type BC-418 MA (Tanita Corporation, Tokyo, Japan) to determine whole body bioimpedance between the hands and feet by applying a constant current of 90 microamps at 50kHz through the body. Measurements taken in the standing position with bare feet placed on the footplate electrodes and the hand grip electrodes held by the side of the body. Whole body impedance used to derive skeletal muscle mass.

  Baseline and one week after the intervention ended

Secondary Outcomes (2)

• Distance shopping carried

  2 x per week at every visit throughout the 4 week intervention

• Perceived exertion

  2 x per week at every visit throughout the 4 week intervention

Study Arms (2)

Control - Usual routine

NO INTERVENTION

Shopping bag carrying

EXPERIMENTAL

Four-week shopping bag carry intervention (15 mins, 2x per week). Performed under supervision in laboratory.

Behavioral: Experimental: Shopping bag carrying

Interventions

Experimental: Shopping bag carrying BEHAVIORAL

Four-week shopping bag carry intervention (15 mins, 2x per week). Performed under supervision in laboratory.

Shopping bag carrying

Eligibility Criteria

• Age: 16 Years - 75 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)

You may qualify if:

• Performing less than 2 days per week of muscle strengthening exercise
• Pass the physical activity readiness questionnaire
• Available during data collection period

You may not qualify if:

• Current or prior history of heart, lung, kidney, endocrine or liver disease or cancer.
• Performing more than 2 days per week of muscle strengthening exercise
• Answered yes to any of the questions in the Physical Activity Readiness Questionnaire
• Available during data collection period

Sponsors & Collaborators

• University of Glasgow: lead

Study Sites (1)

university of glasgow, James Black Building Lab

Glasgow, Glasgow City, G12 8QQ, United Kingdom

Location

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Prof. of Muscle and Metabolic Health

Study Record Dates

• First Submitted: November 17, 2025
• First Posted: December 9, 2025
• Study Start: April 24, 2023
• Primary Completion: July 16, 2025
• Study Completion: July 16, 2025
• Last Updated: December 9, 2025

Record last verified: 2025-12

Data Sharing

• IPD Sharing: Will not share

Locations

GB (1)