Picture a runner at the marathon start line. She’s got carbon-plated “super-shoes” engineered for a better running economy, sweat-wicking fabrics designed to keep her cool and a health-tracking wellness ring measuring every move. But under all the cutting-edge kit, she’s wearing a sports bra designed decades ago, relying on outdated compression tech that hasn’t kept up with the pace of innovation. It’s a paradox hiding in plain sight.

For years, sports bras have been an afterthought in performance gear, despite the fact that 72 percent of female runners experience breast pain while exercising. Worse, we know that without the right support, runners can lose up to 4cm of stride length due to poorly controlled breast movement, which equates to running an extra mile over the course of a marathon.

Now, biomechanics research, material science and real-world testing means innovation in sports bras is finally catching up. This new generation of “super sports bras” is designed to prioritise comfort and performance in equal measures.

As a running retailer, here’s everything you need to know to stay ahead of the curve in 2025.

The Science of Support

As head of the Research Group in Breast Health at the University of Portsmouth, we’ve spent years studying how breast movement affects female athletes — and the role sports bras play in performance.

We know that running generates significant multi-directional breast movement, which, without proper support, results in displacement of up to 15cm per stride. Runners compensate by engaging additional muscles to support, which could lead to greater fatigue, reduced running efficiency, an increased risk of discomfort and long-term soft tissue strain.  

Not all sports bras are designed equally – high-support and low-support bras function very differently and serve different purposes.

• Low-support bras are designed for comfort and freedom of movement, but they often lack the support needed for high-impact activities like running. 

• On the other hand, high-support are designed for activities like running — but often rely on compression to limit movement of the breasts. While effective for this purpose, the excess compression often comes at a high cost — lower breathability, less comfort and impacted natural running mechanics. It can also restrict oxygen intake, making high performance difficult to sustain over long distances.

So, what’s changed? Well, more research into biomechanics and material science has revealed methods to stabilize breast movement dynamically, rather than via rigid containment. 

Smart Materials Are The Future 

Through research, our understanding is that women want apparel that is supportive, comfortable and easy to use, offering a lightweight solution that isn’t too complicated or technical.

Enter adaptive materials. By nature, these fabrics respond to movement — providing stability only where and when it’s needed. Unlike static compression, they remain soft and flexible at rest but stiffen under force, ensuring targeted support without restricting movement.

The application of smart textiles like Rheon can move a sports bra from medium support to high-support, without any additional compression. Rheon is an advanced strain-rate-sensitive polymer, which, when applied in strips to a standard sports bra, can further reduce breast movement by up to 15 pecent. Rather than compressing tissue at all times, Rheon’s material properties allow bras to adjust in real time — a concept already used in high-performance footwear and protective gear. Used in elite sports, including at the 2024 Paris Olympic Games, this performance-focused tech is now making its way into consumer sports bras, with leading brands like Adidas incorporating it into their designs.

Guidance For Running Retailers

With consumer expectations and textile innovation evolving, running specialty retailers need to be prepared for a new standard in sports bra design. Here’s what to consider when selecting or recommending products in 2025.

First, balancing compression, comfort and performance is key. Sports bras should provide stability without restricting movement, working with the runner rather than against her. Consider sports bras that offer dynamic support, rather than relying solely on static compression. Features like adjustable underbands and shoulder straps, racerback and cross-back designs and varying levels of padding all contribute to a better fit and user experience too.

Scientific validation is now becoming a differentiator, too. Unlike running shoes, there are no universal testing standards for sports bras, meaning independent validation is important when assessing performance or claiming specific properties. The University of Portsmouth is home to the world’s first and only dedicated bra testing unit, holding the largest database on sports bra performance. Our research shows that bounce reduction metrics are still one of the most reliable indicators of effective support — and with exciting developments in motion-tracking and biomechanics testing, we can refine how bras function under real-world running conditions. 

Consider the sustainability of your design, too. There’s growing appetite for cutting-edge bio-based, recycled and regenerative textiles that are durable and comfortable without sacrificing performance. 

For run specialty retailers, this is a very real and exciting opportunity. Those who offer performance bras that are validated through research, designed for dynamic movement and built with innovative or responsible materials will leave the competition lagging behind.

The age of the super sports bra isn’t on the horizon — it’s already here.

For more: https://rheonlabs.com/news/new-bra-validation-study-rheon-technology-delivers-dynamic-support-without-added-compression/

Joanna Wakefield-Scurr can be reached at [email protected].