Cooling Yet Boosts Circulation! TENTIAL's Take on Summer Conditioning

TENTIAL, known for its BAKUNE recovery wear, has launched a new line of recovery innerwear designed for summer. The gear features the special fiber "SELFLAME®︎," a general medical device known to improve blood circulation, while also delivering comfort through its cooling touch and moisture-wicking properties.

At first glance, "improving blood circulation" and "providing a cooling sensation" seem contradictory. How did TENTIAL tackle the unique conditioning challenges of summer to successfully combine these two functions? We sat down with developers Mariko Soya and Yukari Morishita to find out.

Innerwear Designed to Support Your Body 24/7

For the Fall/Winter season, TENTIAL began the full-scale rollout of its innerwear equipped with recovery functions.

"Our company's vision is to 'implement conditioning' into daily life. Our signature BAKUNE recovery wear is a prime example, but innerwear is an item that can be worn 24/7, regardless of outerwear, staying closest to the skin. That's why we felt it was significant for TENTIAL to seriously commit to this category," says Morishita.

The Fall/Winter models were highly praised not only for their blood-circulation-improving function as a general medical device but also for their smooth feel against the skin.

"Of course, function is important, but since it's worn directly against the skin, we were meticulous about comfort and texture. As a result, we received a lot of feedback from customers saying, 'This is exactly what I've been looking for,'" Soya explains.

In response to this feedback, they developed recovery innerwear for the summer that retains the blood-circulation-boosting effect while adding a cooling-touch feature.

Summer's Recovery Challenges Go Beyond Just the Heat

When developing their summer product line, TENTIAL focused on something other than just the heat itself.

"While recent attention tends to focus on heatwaves and prolonged periods of heat, we decided to reassess the core conditioning challenges of summer. We concluded that a significant stressor is the drastic temperature difference between the hot outdoors and cold, air-conditioned indoors," says Morishita.

While outdoor temperatures are high, air conditioning in offices and on trains is often cranked up. This, combined with an increased intake of cold food and drinks, can lead to internal chilling, which in turn can lower metabolism and immunity, causing summer fatigue and lethargy.

"Stiffness and fatigue are year-round problems, but in the summer, the physical stress from temperature fluctuations is added to the mix. The body is constantly adapting to these environmental changes, including regulating its own temperature, and that process itself leads to fatigue.

Furthermore, during the day, our brains are in an alert state due to work and other activities. At this time, blood flow to the brain and muscles is prioritized, while circulation to our extremities and internal organs becomes relatively less of a priority. That's why we believe it's crucial to promote blood circulation and support conditioning right from the daytime," Morishita adds.

How Can Cooling Touch and Improved Circulation Coexist?

Still, "promoting blood circulation" and "providing a cooling sensation" might sound contradictory. But Morishita explains that's not actually the case.

"The cooling-touch feature provides a sense of comfort by feeling cool at the moment of contact. It doesn't actually cool the body enough to lower core temperature or constrict blood vessels," says Morishita.

On the other hand, SELFLAME® is a special fiber that uses the radiant action of far-infrared rays to promote blood circulation.

"When people hear ‘promoting blood circulation,’ many probably imagine something that ‘warms’ you up," says Morishita. "However, SELFLAME® doesn't add external heat; it’s a mechanism that utilizes your own body heat. Therefore, promoting blood circulation and a cool-to-the-touch sensation are not contradictory."

This series is proven to promote blood circulation as a general medical device. For this functionality, instead of advertising warmth through heat generation or thermal effects, the evidence of improved blood circulation using one's own body heat serves as the basis for its functionality. In addition to a cool-to-the-touch feel, TENTIAL also prioritized moisture-wicking and releasing properties.

"For example, even if the temperature is high, if the humidity is low, there's relatively little discomfort, right? On the other hand, even if the temperature isn't that high, high humidity that causes clothes to feel stuffy can lead to intense discomfort," says Soya.

This is why we chose a light waffle fabric made primarily of nylon.

"Nylon has excellent moisture-wicking, releasing, and quick-drying properties. We focused not only on the instant comfort from the cool-to-the-touch sensation but also on preventing stuffiness when worn for long periods," Soya explains.

The fabric's surface has a textured light waffle structure to reduce the area of contact with the skin, creating a design that resists stickiness even when you sweat.

"A key feature is that it doesn't cling to the skin, making it easy to maintain a dry, comfortable feel. By combining the cool-to-the-touch sensation, moisture-wicking and releasing properties, and quick-drying capabilities, we aimed to create a comfortable wearing experience for the summer," Soya states.

Furthermore, to combat summer odors, we incorporated the Repur® treatment, which has antibacterial, anti-odor, and deodorizing functions.

"A key feature of the Repur® treatment is that its effects last even after repeated washing. Durability was a crucial element, as clothing gets washed more frequently in the summer," Soya adds.

We also paid close attention to the gentle feel against the skin, a feature that was popular with our fall/winter models. We did away with physical tags; the brand name and size information are all printed directly on the fabric. We also used soft thread for the seams to minimize any skin irritation.

"You wear innerwear all day, so even the slightest irritation can become a source of stress. We pursued total comfort, right down to eliminating scratchy tags and uncomfortable seams," explains Morishita.

Although the summer heat hasn't hit its peak yet, sales are already booming.

"We're also seeing many customers who bought the fall/winter models returning to purchase the new line," Soya mentions.

The men's lineup includes a V-neck that pairs well with dress shirts and two types of bottoms, while the women's line currently consists of a U-neck shirt and over-pants. However, they've already received requests for "more variety" and are considering expanding the lineup.

"While recovery is one part of conditioning, we believe that reducing physical stress from factors like temperature changes is another important aspect of conditioning.

We feel there are still many more approaches we can take precisely because it's innerwear, so we want to continue developing products that support everyday conditioning," Soya says.

When it came to tackling summer heat, the focus has traditionally been all about coolness. However, this innerwear, which balances summer comfort with promoting blood circulation, is a game-changing piece that redefines how to beat the heat from a 'conditioning' perspective.