Mineral-Infused Clothing for Recovery From Muscle Soreness and Muscle Damage After Exercise (PERFICT)

StudySetGo

Status: Enrolling

Conditions: Delayed Onset Muscle Soreness; Exercise-Induced Muscle Damage

Treatments: Other: Muscle-damaging eccentric exercise (drop jumps); Other: Mineral-infused garment; Other: Non-infused control garment

Study type: Interventional

Funder types: NETWORK

Identifiers

NCT07873866

SSG-26-020-001

Details and patient eligibility

About

The goal of this clinical trial is to learn whether wearing mineral-infused clothing helps muscles recover after a hard bout of unaccustomed exercise in healthy adults aged 18 to 45 who have not done lower-body resistance or jump training in the last 6 months.

The main question it aims to answer is: does wearing the mineral-infused garment lead to greater recovery of leg muscle strength (maximal voluntary isometric contraction of the knee extensors) 72 hours after exercise, compared with wearing an identical garment without the mineral infusion?

Researchers will also compare the two garments for recovery of jump performance, muscle soreness and blood creatine kinase (a marker of muscle damage), and will describe garment comfort and tolerability.

Participants will:

• Complete electronic consent, an online screening questionnaire and a video screening call
• Attend the study site on four consecutive days
• On Day 1, complete baseline tests, then perform 100 drop jumps (5 sets of 20) to cause muscle soreness
• Wear their allocated garment for at least 16 hours a day (day and overnight) for the following 72 hours and keep a daily wear log
• Have strength, jump and soreness tests and a finger-prick blood sample at each visit (24, 48 and 72 hours after exercise)

Full description

Unaccustomed exercise with a substantial eccentric component produces exercise-induced muscle damage, characterised by a transient loss of muscle force, delayed onset muscle soreness (DOMS) that typically peaks 48 to 72 hours after exercise, reduced explosive performance and a rise in circulating creatine kinase. Lower-limb garments are widely used to aid recovery, and meta-analyses of compression garments report small to moderate benefits for strength, power and perceived soreness. Mineral-infused textiles, marketed as re-emitting body heat as far-infrared radiation, form a poorly characterised category of recovery garment, and their effect on recovery from muscle-damaging exercise is unknown.

Design: single-site, randomised, double-blind, sham-controlled, parallel-group trial with 1:1 allocation, conducted at a StudySetGo study site in Exeter, United Kingdom. Randomisation uses computer-generated permuted blocks of varying size, stratified by sex. The control garment is manufactured to the same external specification, fabric, colour, sizing and finish as the active garment but without the mineral infusion, and is supplied in identical coded packaging.

Procedures: screening and consent are completed remotely (electronic consent and screening questionnaire via PandaDoc, followed by a Zoom screening call). On Day 1, participants are randomised and issued their garments, then complete baseline assessments in a fixed order: capillary blood sample, soreness visual analogue scale (100 mm, during a bodyweight squat), maximal voluntary isometric contraction (MVC) of the knee extensors of the dominant limb and squat jump. Participants then perform a muscle-damaging protocol of 100 drop jumps (5 sets of 20, 10 s between jumps, 2 min between sets) under one-to-one supervision, followed by 0-hour assessments. Garments are worn for a minimum of 16 hours per day (approximately 8 hours waking and 8 hours overnight) through the 72-hour recovery period, removed only for assessments and personal care, and wear is recorded in a daily log. Assessments are repeated at 24, 48 and 72 hours. Participants keep their habitual diet and caffeine intake, have their last meal and any caffeine at least 2 hours before testing, attend at the same time of day (plus or minus 1 hour) on each visit, and avoid alcohol, other recovery modalities, anti-inflammatory medication and strenuous exercise during the study. A Study Exit Questionnaire at 72 hours records garment comfort and tolerability and the participant's guess of allocation.

Sample size: based on Hill et al. (2017), a difference of 8.7 percentage points in MVC recovery at 72 hours (Cohen's d = 0.888), two-tailed alpha 0.05 and power 0.80 require 42 participants (21 per group); allowing approximately 20% dropout, 52 participants (26 per group) will be enrolled.

Analysis: the primary analysis is on the intention-to-treat population using a linear mixed-effects model with group, timepoint and group-by-timepoint interaction as fixed effects, pre-exercise baseline as a covariate and participant as a random effect. Secondary models are additionally adjusted for sex. Pre-specified sensitivity analyses examine hormonal status, and a per-protocol analysis includes participants meeting the wear-adherence threshold (mean of at least 16 hours per day with no day below 12 hours). Creatine kinase is log-transformed and reported as geometric mean ratios.

Enrollment: 52 estimated patients

Sex: All

Ages: 18 to 45 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• Adults aged 18 to 45 years inclusive
• Body mass index between 18.5 and 29.9 kg/m2 inclusive
• No participation in structured lower-limb resistance training or plyometric (jump) training within the previous 6 months (structured training: a planned programme of exercise against external load or bodyweight loading targeting the lower limbs, performed at least once per week for 4 or more consecutive weeks)
• No history of injury that may impair the ability to perform maximal exercise
• Willing to wear the allocated study garment for a minimum of 16 hours per day (approximately 8 hours waking and 8 hours overnight) throughout the 72-hour post-exercise recovery period, and during the muscle-damaging exercise protocol
• Willing to maintain habitual diet and physical activity, including usual caffeine intake; to have the last meal and any caffeine at least 2 hours before each testing session; and to abstain from alcohol throughout the trial
• Able to attend the study site on four consecutive days
• Able to provide written informed consent
• Able to read, understand and communicate in English
• Currently living in the United Kingdom

Exclusion criteria

• Current use of non-steroidal anti-inflammatory drugs, corticosteroids or other anti-inflammatory medication
• Current use of statins
• Use of dietary supplements with known anti-inflammatory or antioxidant activity
• Diagnosed muscle, neuromuscular or connective tissue disorders
• Bleeding disorders or current use of anticoagulant medication
• Known allergy or sensitivity to any material used in the study garment, or a history of textile or contact dermatitis
• Pregnancy, breastfeeding, or intention to become pregnant during the study period
• Current participation, or participation within 4 weeks of screening, in another interventional clinical trial
• Any condition that, in the opinion of the investigator, would compromise participant safety or data integrity
• Current use, or use within 4 weeks, of any form of compression garment
• Any response to the general health questions in the Screening Questionnaire indicating a contraindication to maximal exercise

Trial design

Primary purpose: Basic Science

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Quadruple Blind

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52 participants in 2 patient groups

Mineral-infused garment

Experimental group

Description:

Participants wear mineral-infused socks and leggings during the muscle-damaging exercise protocol and for a minimum of 16 hours per day throughout the 72-hour recovery period.

Treatment:

Other: Mineral-infused garment

Other: Muscle-damaging eccentric exercise (drop jumps)

Non-infused control garment

Sham Comparator group

Description:

Participants wear socks and leggings manufactured to the same specification, fabric, colour, sizing and packaging as the active garment but without the mineral infusion, on the same wear schedule.

Treatment:

Other: Non-infused control garment

Other: Muscle-damaging eccentric exercise (drop jumps)