There is a training method picking up serious momentum in 2026. It goes by a few names. Run/walk. Interval running. Some people call it Jeffing. The idea is simple: you alternate between running and walking throughout your session, from the very start, using structured intervals rather than stopping because you have to.
What was once considered a beginner's tool is now something a lot of experienced runners are taking seriously. And for good reason. The evidence suggests it reduces injury risk, allows people to run for longer, and makes training feel sustainable over months rather than weeks. Strava data from 2026 shows a clear shift toward longer, easier sessions. Run/walk sits right inside that shift.
For Re., this trend is interesting for one specific reason: it changes how much time you spend outdoors, and the kinds of conditions you run through.
Why Run/Walk Puts You Outside Longer
The whole point of the run/walk method is that it extends your session. You recover during the walk intervals, which means you can keep going well past the point where a straight run would have ground you down. A runner who might have cut their session short at 45 minutes suddenly finds themselves out for 70 or 80.
That is genuinely good for your fitness. It is also genuinely relevant to your eyes.
UV radiation accumulates over time. Every minute you are outside adds to the total dose your eyes receive. A 40-minute easy run and an 80-minute run/walk session are not equivalent in terms of UV exposure, even if both feel comfortable. The longer session delivers roughly twice the UV load, often across more varied light conditions as the morning progresses or the afternoon shifts.
Most runners think about UV protection in terms of skin. Sunscreen on the face, arms, shoulders. The eyes rarely come up. But the cornea absorbs UV radiation, and cumulative exposure over years of training is a real concern, not a marginal one. UV reaches your eyes even on cloudy days, and winter in Australia does not give you the pass most people assume it does.
The Light Condition Problem
Here is something specific to run/walk that does not apply to most other training methods: your sessions tend to span more of the day's light cycle.
When you are running straight, your session has a start and an end, and the light at both points is relatively similar. Run/walk sessions stretch longer, which means if you start at 6am, you might still be out at 7:30. The sun angle changes substantially in that window. Early morning light is low, diffuse, and often coming directly at you. Mid-morning light is brighter and overhead. Glare off roads, footpaths, and water is entirely different at each point.
This is the exact scenario where a fixed-tint lens starts working against you. In Australian autumn and winter, the sun angle is lower than most runners account for, which makes glare more aggressive even at moderate times of day. If your lens is dark enough to handle the bright mid-section of your run, it is probably too dark for the first 20 minutes. And vice versa.
The same logic applies if you are doing your run/walk sessions in the evening. You head out in reasonable afternoon light and come back in near-dark. In Australian winter, that window can arrive earlier than you expect.
What a Photochromic Lens Actually Does Here
A photochromic lens adapts its tint to the light level around you. In full sun, it darkens to protect your eyes from glare. In low light, it goes nearly clear so your vision is not compromised. It does this continuously and automatically, which is exactly what a run/walk session across changing light demands.
The Re. Adaptor lens is our photochromic option. It was designed with variable-light running specifically in mind. Early mornings, late afternoons, trail runs where you shift between open sun and shade, and yes, long run/walk sessions where the light changes significantly during the session. The lens goes near-clear in low light and darkens in direct sun, all while maintaining UV400 protection throughout.
It is not polarised, which matters to flag. If glare from flat water or wet roads is a significant issue in your usual training locations, that is worth thinking about. Polarised and photochromic serve different purposes, and the Adaptor prioritises adaptability over glare-cutting.
If you want both, the Re. Infinity lens is the full system: photochromic plus polarised plus permanent anti-fog. It is our most capable lens and the one we recommend for runners who want a single pair that handles everything without compromise. The difference between the Adaptor and Infinity comes down to whether you need polarisation and anti-fog on top of the photochromic base.
Run/Walk and UV Accumulation Over a Training Block
One more thing worth understanding: the UV argument is not just about individual sessions. It is about the cumulative load across a full training block.
If you are using run/walk to build up toward a half marathon or marathon, you are likely doing three to five sessions per week over several months. Australian marathon training season runs through autumn and into winter, which means most of your long sessions are happening in the morning, in lower sun angles, with significant UV still present. The UV index does not need to be high for cumulative damage to occur. It just needs to be consistent.
Run/walk amplifies this simply because the sessions are longer. A runner doing four 90-minute run/walk sessions per week is accumulating six hours of outdoor UV exposure. That is before any other time spent outside. UV400 protection in your sunglasses means every wavelength of UV radiation is blocked. It is not optional gear for this kind of training load.
The Sunday long run is where most of this UV exposure stacks up, and run/walk makes those long runs longer. Worth keeping in mind.
The Practical Read
The run/walk method is a genuinely smart way to train. It extends your session length, reduces injury risk, and keeps you consistent. Those are real benefits, and we get why it is catching on.
The implication for your kit is straightforward. If you are using run/walk to run for longer across more of the day's light cycle, a fixed-tint lens becomes the weak link. It was designed for a narrower window. The same logic applies to Zone 2 easy running, where you are out for longer at a comfortable effort. The method changes. The UV does not.
The Adaptor lens handles variable light well, at $160 AUD for the Re.flex frame. If you want the full system with polarisation and permanent anti-fog, the Infinity is the answer. Both work. The choice comes down to your conditions and what you want from the lens.
You can use our lens guide to work through the options, or find your pair if you want a faster answer. Either way, if you are spending more time outside, it is worth getting the lens right.
Browse the full range at Re. running sunglasses.
Tim Golubev
Founder, Re. (Re Your Run)
Tim built Re. after years of running in sunglasses that bounced, fogged, and ended up on his forehead. After discovering the UV damage that builds up without eye protection (even on cloudy days) and hearing the same frustrations from hundreds of other runners, he decided it was a problem worth fixing properly. With a background in Product across multiple industries, he approached it like any product problem: figure out what's broken, then build something that actually fixes it. He runs daily, co-founded Rose Bay Run Club, and Re. is his attempt to make one less thing that gets in the way of a good run.
