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Effect of Far Infrared Reflecting Sleepwear on Recovery and Sleep

Effect of Far Infrared Reflecting Sleepwear on Recovery and Sleep

Status
Completed
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT04273789
Enrollment
18
Registered
2020-02-18
Start date
2020-02-17
Completion date
2020-07-02
Last updated
2020-08-03

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Exercise Induced Muscle Damage

Brief summary

Far infrared light (FIR, 5.6-1000 µm) penetrates our skin and reaches the underlying tissue up to 4 cm and promotes widening of the blood vessels (vasodilation). This results in increased blood flow in the tissue under the skin, without heating up the skin itself. Increased blood flow allows more oxygen to reach the muscles and more metabolic waste products to be transported away from the muscles. Studies assessing clothing containing an FDA approved ceramic particles covered yarn that reflect FIR light showed delayed onset muscle pain decreased and a reduction in inflammatory markers in professional athletes. The aim of this study is to investigate the effect of far infrared reflecting sleepwear on night-time recovery and Sleep in a broader population, namely physically active adults (non-professional).

Detailed description

Far infrared light (FIR, 5.6-1000 µm) penetrates our skin and reaches the underlying tissue up to 4 cm and promotes widening of the blood vessels (vasodilation). This results in increased blood flow in the tissue under the skin, without heating up the skin itself. Increased blood flow allows more oxygen to reach the muscles and more metabolic waste products to be transported away from the muscles. Thus, exposure to FIR might aid the process of recovery in muscle groups lying close to the skin. Indeed several research groups could show that exposure to FIR aids recovery. 30 min intense far infrared exposure enhanced recovery from exercise-induced muscle damage in highly trained runners. Studies assessing clothing containing an FDA approved ceramic particles covered yarn that reflect FIR light showed delayed onset muscle pain decreased and a reduction in inflammatory markers. Since a large part of our recovery takes place during sleep it is of interest to assess the effect of FIR on night-time recovery and sleep itself. One study showed that FIR exposure during sleep increased the amount of non-rem sleep in rats. This effect has not been replicated in humans, possibly because increased temperature is not beneficial for sleep and thus should be kept constant. The aim of this study is to investigate the effect of far infrared reflecting sleepwear on night-time recovery and sleep. Sleepwear of a breathing and thermoregulating material, with a layer of FIR reflecting minerals printed on the outer surface, will be assessed. Physically active males are invited to participate in two bouts of exercise in the lab, separated by one week. The exercise bout targets one leg, the second week the other leg is exercised. Starting the protocol with the dominant/non-dominant leg (determined in first session) will be randomized. Participants will then wear the FIR reflecting sleepwear and placebo sleepwear respectively at home for the 7 nights following each bout of exercise. To assess sleep quality activity will be measured using wrist worn activity trackers. To assess recovery physical performance will be measured (max. single leg force and jump height), knee range of motion and thigh circumference of each leg at before each exercise bout, after each exercise bout and at three days after each exercise bout. Per exercise bout muscle soreness will be induced in one leg of the two legs respectively, to account for a repeated bout effect. It is hypothesized that more overnight recovery takes place during nights with FIR reflecting sleepwear compared to nights with placebo sleepwear.

Interventions

DEVICEFar infrared reflecting sleepwear

100% microlyocell sleepwear (shorts + shirt) with a ceramic print that reflects far infrared light (FIR, 5.6-1000 µm) emitted by the human body. Since FIR active garments are not powered, but reflect recycle light energy emitted by the body of the wearer, they have irradiances between 0.1-5 mW/cm\^2.

DEVICEPlacebo sleepwear

100% microlyocell sleepwear (shorts + shirt)

Sponsors

Swiss Federal Institute of Technology
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
TREATMENT
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)

Masking description

Prior to the study participants are informed about the study protocol, measurements and risks, but not about the study purpose. Debriefing is conducted verbally, as well as in written form and includes the signing of a second consent form. The experimenters conducting the measurements and analysis is not aware of the randomization. Unblinding is planned for interim analysis after 10 datasets have been collected and at study end.

Eligibility

Sex/Gender
MALE
Age
18 Years to No maximum
Healthy volunteers
Yes

Inclusion criteria

* Physically active (\>3h of sports per week) * BMI \< 25

Exclusion criteria

* Sleep problems (assessed using standardized questionnaire included in entrance questionnaire) * Cardiovascular problems (self-reported in entrance questionnaire) * Sensitive skin/allergies that present on a skin level (self-reported in entrance questionnaire) * Knee pain while exercising (self-reported in entrance questionnaire) * Night shift work during study period

Design outcomes

Primary

MeasureTime frameDescription
Change in time of flight during jump (s)72 hours post exercise bout in week 1 and week 2Time of flight during jump is the time between offset and landing. The influence of the intervention is determined by comparing the values 72h post exercise bout of each week.
Change in maximum isometic leg force (N)72 hours post exercise bout in week 1 and week 2Maximum isometic leg force will be measured while participants are lying on their back with knees 90 Degrees bend. They press against a vertically mounted force plate. The average of 3 measurements separated by 1 minute break is used.The influence of the intervention is determined by comparing the values 72h post exercise bout of each week.
Change in leg circumference (m)72 hours post exercise bout in week 1 and week 2Circumference of the tight while standing will be measured using a measurement tape. The average of 3 measurements separated by 1 minute break is used. The influence of the intervention is determined by comparing the values 72h post exercise bout of each week.
Change in knee range of motion (Degrees)72 hours post exercise bout in week 1 and week 2Active range of motion of the knee while lying on the stomach is determined using a goniometer. The influence of the intervention is determined by comparing the values 72h post exercise bout of each week.
Change in muscle soreness (rating on visual analog scale)1, 2, 3, 4, 5, 6 days post exercise bout in week 1 and week 2Subjectively experienced delayed onset muscle soreness measured using a visual analog scale. The change in soreness over time is of interest, as well as the influence of the intervention. The influence of the intervention is determined by comparing the values 1, 2, 3, 4, 5, 6 and 7 post exercise bout of both weeks.

Secondary

MeasureTime frameDescription
Activity during night1, 2, 3, 4, 5, 6 days post exercise bout in week 1 and week 2Activity during night is measured using a wristworn actigraphy tracker. Based on this data sleep onset latency, sleep eficiency, sleep duration, number and duration of awakenings are calculated using validated algorithms. The influence of the intervention is determined by comparing the values 1, 2, 3, 4, 5, 6 and 7 post exercise bout of both weeks.

Countries

Switzerland

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026