Functional Sleepwear—the evolution of smart pyjamas
New development to promote our nightly recovery
We can only make progress in training if we prioritize our recovery accordingly. And good sleep quality is our most important "recovery tool" - while we sleep our body can release essential growth hormones, reduce inflammations and internalize new learning. Shifts in our body temperature is one of the most important levers of our body for the control of the sleep-wake rhythm, disturbances of this cycle have an adverse effect on our sleep quality. Inspired by modern sportswear, Dagsmejan has developed a new type of sleepwear that effectively supports the natural thermoregulation of the sleeping body to ensure the best temperature for sleep.
Sleep, Temperature & Thermoregulation
Inspired by modern sportswear, Dagsmejan has developed a new type of sleepwear that supports the natural thermoregulation of the sleeping body to help us keep the best temperature for sleep. Our sleep is initiated by two factors: the rise in the melatonin level and the drop in body temperature in the early evening hours. The lowering of the body temperature can be achieved by convection, i.e. by transporting more blood to the extremities, and by sweating and evaporation. In the course of the night, the core body temperature drops until it is approx. 1° below that of the awake state. From this point, around 4 o'clock in the morning, the body begins to prepare for waking up, the core temperature begins to rise again. Unlike during the day, the core body temperature and the distal temperature largely converge. Disturbances of this natural thermo-regulation lead to a lower sleep quality, which manifests itself in interruptions, too early awakening or too short SWS ("Slow Wave Sleep") or REM phases. Our natural thermoregulation is influenced on the one hand by endogenous factors such as our general state of health, stress level, hormone levels or diet, on the other hand we can support the quality of sleep by exogenous factors such as room temperature (16-19°C) and the design of our sleep system. Good solutions have been available for mattresses, bed covers and blankets for some time now. The first layer - the layer that we wear directly on the skin - has so far been neglected in this system.
Requirements for functional sleepwear
Within the framework of an interdisciplinary research project, four core requirements for functional sleepwear have been defined: 1) Breathability: supports natural thermoregulation during the night, dissipates excess heat, protects against cooling. 2) Moisture regulation: absorbs moisture and supports evaporation; transports excess moisture away from the skin layer and thus ensures that the cooling effect of perspiration is not exceeded or that we find ourselves in clammy textiles. 3) Haptics: fine surface design to avoid irritation caused by pressure points and friction points. 4) Comfort: sleep-ergonomic design, maximum freedom of movement.
The concept of the smart pajamas
Based on the functional requirements, the team has developed a new type of sleepwear on two levels: Functionalised fibres and sleep-optimised design.
In the project more than 100 fibres and fibre combinations were tested according to the defined criteria. These test series have shown that natural fibres are superior to polymer fibres on three of the four defined levels. Only in moisture control do polymer fibers show advantages. The hydrophilic basic properties of natural fibres mean that the moisture absorption limit is quickly reached in the case of strong sweat formation, which is expressed in unpleasantly clammy fabrics. Due to the hydrophobic basic properties of polymer fibres, this moisture is much better removed. Based on this knowledge, the team has developed a new, functionalised fibre: a natural fibre obtained from beech wood is given a hydrophobic finish in a new process - a fabric has been knitted from it which thus optimally combines the basic properties of natural fibres with high moisture-regulating properties. As a result, these fibres can absorb up to 50% of their own weight in moisture without feeling clammy. In addition to the fibre properties, the type of knitting selected and the knitting technology (in particular the number of knitting needles per inch, yarn tension) also have a major influence on the functional properties of a fabric. Testing different knitting technologies has shown that the combination of several knitting types can further improve climate comfort. While seamlessly integrated functional zones in sportswear (with synthetic fibres) are already widespread today, the team has broken new technological ground by implementing this concept with natural fibres.
The sleepwear was tested along three levels, with a conventional cotton pyjama serving as a reference: 1. Physical: Are the thermoregulating properties of the sleepwear superior to a conventional cotton fabric? 2. physiological: Does the sleepwear support the natural thermoregulation of the body better than an ordinary cotton pyjama to ensure that we keep the best temperature for sleep? 3rd tactile: Is the fabric softer on the skin than a regular cotton pyjama?
- Physical: The "moisture distribution" is a measure of the amount of moisture absorbed. The more moisture a fabric absorbs, the wetter it can feel when our body releases moisture at night. The comparative test has shown that the Dagsmejan fabric leads moisture away from the skin about 4.5 times better than the reference product. The air permeability of a substance is a measure of how much heat is dissipated from the substance in a given time. A textile that dissipates little heat from its surface feels warm, one that dissipates heat but cool. Different knitting techniques lead to different properties. The sleepwear tested here combines super-fine knitting technology and ergonomically positioned functional zones, which allow more than 6 times higher breathability than cotton.
- Physiological: More important than the pure physical properties of the fabric is how its construction actually supports the sleeping body at night. The study showed that this sleepwear keeps the body in the climatic comfort zone for the whole 8 hours, whereas cotton loses its function already after a short time (strong heating of the body and strong moisture build-up); the sleepwear thus keeps the temperature in the “sleep cave” about 1° lower than the reference product. This ensures the best temperature for sleep.
- Tactile: While we sleep, our skin is supplied with more blood as our cells regenerate. Our skin therefore reacts very sensitively to friction. In addition to eliminating all disturbance factors in the design, the tested fabric is characterized by a very fine haptic due to an innovative finishing. The friction coefficient of the fabric is thus around 2x lower than that of ordinary cotton.
Good sleep is one of the key factors for our regeneration and but also to deliver peak performance when it matters. Our natural thermoregulation significantly determines our sleep quality.
Extensive tests have shown that Dagsmejan sleepwear is clearly superior to conventional pyjamas in terms of supporting these processes. Within the framework of a holistic training approach, functional sleepwear is therefore a pragmatic, effective instrument. A smart pajamas can make a real difference to our recovery.