The best time to use an infrared sauna depends on what you’re trying to get out of it. Morning sessions between 6 and 10 AM support alertness and energy, while evening sessions between 5 and 9 PM promote relaxation and better sleep. Beyond time of day, “when” also means how often, how long each session should last, and whether to pair it with exercise. Here’s how to dial in each of those variables.
Morning vs. Evening Sessions
Your body’s hormonal rhythm shifts throughout the day, and matching your sauna session to that rhythm amplifies the benefits. In the morning, roughly 50 to 70 percent of your daily cortisol output happens within 30 to 45 minutes of waking. A sauna session during this window rides that natural wave of alertness, boosting mood and metabolic activation without caffeine or other stimulants. If you want to feel sharp and energized heading into your day, mornings are the stronger choice.
Evening sessions work differently. By 5 to 9 PM, cortisol is naturally declining and your body is ramping up melatonin production toward its nightly peak around 10 PM. An infrared sauna during this window supports that transition, potentially lowering nighttime cortisol by 15 to 25 percent and improving deep sleep by 10 to 15 percent. This is the most popular timing among regular sauna users, fitting naturally after work and before dinner.
Timing a Session for Better Sleep
If sleep is your main goal, the key detail is finishing your session two to three hours before bed. The sauna raises your core temperature, and when it drops back down afterward, that cooling mimics the body’s natural signal that it’s time to rest. This is the same drop in core temperature your brain relies on to initiate sleep. Sitting in a sauna at 9 PM and trying to fall asleep at 9:30 won’t work nearly as well as a 7 PM session that gives your body a full cooldown window.
Before or After a Workout
Post-workout is the better call for most people. Using an infrared sauna before exercise dehydrates you and can tire you out before you’ve even started training, which limits your performance and increases your risk of overheating during the workout itself.
After a workout, the benefits stack up. Infrared heat penetrates about 3 to 4 centimeters into muscle and soft tissue, which helps ease the soreness that comes from the micro-tears and inflammation your muscles experience during exercise. One study found that people who used an infrared sauna after strength and endurance training reported meaningful relief from pain and muscle soreness compared to those who didn’t.
There’s also a performance angle. Research on athletes who used saunas after daily workouts showed increased plasma volume, the liquid portion of blood. More plasma means better blood flow, more efficient oxygen delivery to muscles, and a higher stroke volume (the amount of blood your heart pumps per beat). Over time, that can translate into better endurance and work output in subsequent sessions.
How Often to Use One
Two to three sessions per week is the standard recommendation for general health benefits. At twice a week, you get a moderate reduction in cardiovascular risk. Three times a week adds mental health benefits on top of that. Research on frequent sauna users shows a dose-response relationship: people who use a sauna four to seven times per week see up to a 50 percent decrease in cardiovascular-related mortality compared to once-a-week users. That doesn’t mean you need to go daily, but it does suggest that consistency matters more than occasional long sessions.
How Long Each Session Should Last
Most infrared sauna sessions fall between 15 and 30 minutes. If you’re new to it, start with 10 to 15 minutes. The temperatures are lower than a traditional sauna (typically 120 to 150°F versus 150 to 195°F), but the infrared heat penetrates deeper, so it can still catch beginners off guard. Gradually add a few minutes per session as you build tolerance. Experienced users typically settle into 30 to 40 minute sessions comfortably.
Longer is not always better. Staying in past the point of comfort doesn’t accelerate results; it just increases your risk of dehydration and lightheadedness.
Hydration Before and After
Drink 16 to 20 ounces of water (roughly two full glasses) about 30 to 60 minutes before your session. Bring a bottle of room-temperature water in with you to sip during the session if needed. Afterward, drink another 16 to 24 ounces to replace what you lost through sweat. Adding electrolytes to your post-sauna water helps if you tend to sweat heavily or feel drained afterward.
The Cooldown Period
Your body needs a minimum of 10 minutes after a session to readjust its core temperature. Don’t jump straight into intense activity or a hot shower. Instead, sit somewhere comfortable, use a cool towel if one is available, and let your heart rate settle back to normal. This cooldown isn’t optional; it’s when your body transitions from the heat stress state back to baseline, and rushing it can leave you dizzy or fatigued.
Who Should Avoid Infrared Saunas
Certain health conditions make infrared saunas risky. Heart conditions top the list: unstable coronary artery disease, heart failure, heart valve disease, and arrhythmias like atrial fibrillation all require medical clearance before you sit in one. Low blood pressure and kidney disease increase your vulnerability to dehydration and overheating.
Medications matter too. Diuretics, blood pressure drugs, and anything that causes dizziness can amplify the effects of heat exposure in dangerous ways. If you have neurological conditions that affect your ability to sense temperature, you’re at higher risk for burns. Pregnancy is another clear reason to skip sauna use entirely. And if you have open wounds or are recovering from surgery, wait until those areas are fully healed before starting sessions.
If you have implanted medical devices, including pacemakers or insulin pumps, check with your doctor first. The infrared wavelengths and heat can potentially interfere with certain devices.