If you're reading this, you've probably already been on the L1 product page once or twice. This is everything that page doesn't have room for — every real question we get about far infrared therapy for back pain, wearable heat, and the L1 itself.
I've grouped it by what people actually ask, in roughly the order they ask it. Nothing here is a sales pitch. If the honest answer to a question is "it depends" or "we don't know yet," that's what it says.
Quick Answers
- Far infrared therapy warms tissue itself, not just the skin's surface — it reaches roughly 1.5 inches deep, which is deeper than a standard heating pad's surface heat.
- The L1 is a wearable far infrared device for the lower back. It eases stiffness and improves mobility. It does not repair structural damage or replace a diagnosis.
- Most members run 15 to 20 minute sessions, once or twice a day, starting around 120°F.
- It's safe for daily use at recommended settings. If you have reduced sensation, are pregnant, or have an implanted device, read the safety section before starting.
The Basics
What Is Far Infrared?
Infrared is the band of light that sits just past red on the visible spectrum. You can't see it, but you feel it — it's the warmth coming off a fire, or the heat on your face from the sun on a cold day with no UV attached to it.
Far infrared is the long-wavelength end of that band. What makes it useful for therapy is that it doesn't just warm the air around you or the outer layer of your skin. It transfers energy into the tissue itself, so the warming happens from inside the muscle rather than on top of it — the difference between surface heat and deep heat.
What Is the L1?
It's a wearable far infrared unit for your lower back. A heating element sits against the lumbar area, held in place by a stretch wrap made from FIR-infused fabric. The whole thing is less than an inch thick, cordless, and runs off a rechargeable USB-C battery. You control temperature and session length from a free app on your phone.
Two sizes: standard fits a 25 to 40 inch waist, and an extender fits 40 to 60 inches.
How Does Far Infrared Actually Work on My Back?
Three things happen when deep tissue warms up.
Blood flow increases, which brings oxygen in and carries metabolic waste out. Connective tissue becomes more pliable, so the same stretch buys you more range of motion than it would cold. And the nervous system tends to turn down its guarding response, which is often what stiffness actually is.
The metaphor I keep coming back to is a rubber band straight out of the freezer. Cold, it resists and snaps. Warm, it does what a rubber band is supposed to do. Your lower back is doing the same math every morning — which is also part of why mornings tend to be the worst of it. Spinal discs absorb fluid overnight while you're unloaded and lying still, and lose some of that fluid, along with some flexibility, as you move through the day. Warm tissue tolerates that transition better than cold tissue does.
Does It Work?
Is There Real Research Behind Infrared Therapy for Back Pain?
Yes, though I want to be careful about how much weight I put on it.
The study most worth reading is a double-blind, placebo-controlled trial of infrared therapy for chronic low back pain. Over seven weeks, pain scores in the treated group fell from 6.9 out of 10 to 3.0. The placebo group went from 7.4 to 6.0. The difference between groups was statistically significant.
The honest caveat: it was 39 people. That's a small trial, and one small trial is not a settled body of evidence. I'd rather tell you that than have you find it yourself and wonder what else we rounded off. For the fuller picture beyond this one trial, see our breakdown of the far infrared therapy research.
What I'd put more weight on, personally, is the volume of consistent member feedback we get about the same specific things: getting out of bed easier, sitting through a flight or a long drive without paying for it afterward, playing a full round and not dreading the next morning.
Will the L1 Fix My Back Pain?
No, and I'd be careful with anyone who tells you a device will.
The L1 is a heat therapy tool. It makes tissue warmer, more pliable, and better perfused. That helps enormously with stiffness, with warming up before load, and with recovery after. It does not repair structural damage, and it isn't a substitute for physical therapy, imaging, or a diagnosis if something is actually wrong.
If you have pain that's new, sharp, radiating down a leg, or getting worse, see someone about it before you buy anything. For more on how we think about treating pain beyond any one device, that's a good next read.
Using the L1
When Should I Use It?
The three highest-value windows:
Before activity. Warm tissue tolerates load better than cold tissue does. This is the single most underused case, especially for golf and lifting — see our full guide to warming up before activity.
After sitting still for a long time. Mornings, long flights, long drives, and the back half of a desk day all produce the same problem — tissue that's gone quiet and stiff.
After activity. Post round, post training session, or anything that loaded your back — this is where recovery habits matter most.
You do not have to pick one. Most members who get the best results run one anchored daily session and add a second around whatever stressed their back that day.
How Often Should I Use It?
More often than most people do. That's the most common mistake by a wide margin.
Think of it more like brushing your teeth than like taking aspirin. One session feels good. Consistent sessions build a baseline you can actually notice. Frequency beats duration, so two fifteen-minute sessions will do more for you than one thirty-minute session.
How Long Should a Session Be?
Fifteen to twenty minutes is the average session, and it's where most members land. The app caps any single session at thirty minutes.
There isn't much of a bonus round past that window. Once tissue is fully warmed and circulation is up, more time isn't buying you much, and it's time you're less likely to spend again tomorrow. Two shorter sessions in a day will do more for you than one long one.
What Temperature Should I Use?
Start at 120°F and adjust from there — there's no single right number, just the number that works for you in a given situation.
You set both temperature and timer in the app. Heat tolerance varies, and so does what a given setting feels like on your back on a given day. The L1 heats up fast by design, so within a couple of minutes you'll know whether you want to nudge it up or bring it down. That's the whole calibration process.
As a rough starting frame: most members sit lower for recovery and maintenance, and go warmer for a warmup before activity, since the goal there is getting tissue ready quickly. Once you've run it a handful of times you'll stop thinking about it and just know your setting.
Warm enough to clearly feel, never hot enough that you're gritting through it. Hotter is not the goal and it isn't more effective.
Can I Move Around While Wearing It?
That's most of the point. It's cordless, less than an inch thick, and sits flat enough to disappear under a shirt.
Members wear it making coffee, on a work call, driving to the course, walking the dog, and through the first stretch of a show after dinner. The reason this matters isn't convenience. It's that a device you have to lie still for gets used twice and then lives in a drawer.
How Is the L1 Different From a Heating Pad?
wo things, and the second one matters more than people expect. First, the therapy itself. Far infrared reaches deep into the tissue. Surface heat feels good, but it stops there. Second, the form factor. The L1 is the only one you can put on and then go live your day. The best therapy in the world does nothing if it keeps you pinned to the couch for 20 minutes.
Safety
Are There Any Risks?
Far infrared heat is well tolerated by most people, but it's still heat, and normal heat therapy precautions apply.
Don't use it over broken or irritated skin, over a fresh injury that's still swollen, or on top of topical creams like menthol or capsaicin, which can react badly with heat. Don't sleep in it. If your skin gets red and stays red after a session, that's your signal to lower the temperature or shorten the session.
Talk to your doctor first if you have reduced sensation in the area, including from diabetic neuropathy, since the usual warning signal that something is too hot may not reach you. Same goes if you're pregnant, if you have an implanted electronic device such as a pacemaker, or if you're being treated for a condition affecting circulation or the skin.
None of that is unique to us. It's the standard list for any heat therapy, and it's short for a reason. But you should read it rather than assume.
Is It Safe to Use Every Day?
Yes, at the recommended temperatures and session lengths. Daily use is what we actually recommend.
Practical Questions
How Long Does the Battery Last?
Up to 120 minutes depending on temperature. Most people get 80 to 100 minutes of use per charge. Higher settings above 135°F draw more power and shorten that.
At a fifteen-minute daily session, you're charging it roughly once a week.
How Do I Charge It?
Any USB-C charger works. The included one is fine, though a higher-capacity USB-C charger will fill it faster.
How Do I Clean It?
Remove the heating element first, then wash the wrap according to the care label. For anything minor, a damp cloth on the spot is enough.
Is the App Free?
Yes, on both iOS and Android. There's no subscription attached to the device.
Can I Use HSA or FSA Funds?
Yes. We work with Burst, which connects your purchase to your HSA or FSA benefits so you can use pre-tax dollars.
What If It Isn't for Me?
Thirty days, full refund or exchange. If it arrives damaged or defective, we cover return shipping.
That policy exists because this is a device you have to actually live with to evaluate. A week isn't enough to know. A month is.
Ready to Try the L1, or Still Deciding?
If everything above answers what you needed: Get the L1 →
Not ready yet, but want to keep learning? Join the list — that's also where most of the questions on this page came from in the first place.
Still Have a Question?
Ask us directly — use the contact form on this site, or reply to any of our emails if you're already on the list. Either way, it goes to a real person.
If enough people ask the same thing, it ends up on this page.
