When a Navy SEAL is under fire, hypothermic in the surf zone, or 80 hours into Hell Week with no sleep — one of the most powerful tools they have costs nothing and requires no equipment. It's their breath.
By Coach Brad McLeod — Former Navy SEAL, Founder of SGPT Online
What Is Box Breathing?
Box breathing — also called tactical breathing or 4-4-4-4 breathing — is a controlled breathing technique used by Navy SEALs, Special Forces operators, elite athletes, and high-performance professionals to regulate the nervous system under stress.
The technique is simple:
- Inhale for 4 counts
- Hold for 4 counts
- Exhale for 4 counts
- Hold for 4 counts
Repeat for 4–6 cycles. That's it. Four sides of a box — hence the name.
Simple to learn. Powerful in practice. And backed by science.
Why It Works: The Science Behind Box Breathing
When you're under stress — physical, mental, or emotional — your sympathetic nervous system activates. Heart rate spikes. Breathing becomes shallow and rapid. Cortisol floods your system. Your brain shifts from rational thinking to survival mode.
This is useful when you need to sprint away from danger. It's not useful when you need to make a clear decision under fire, push through the last mile of a ruck, or hold your form on the 90th pull-up of Murph.
Box breathing activates the parasympathetic nervous system — the body's rest-and-digest response. Specifically:
- Slows heart rate within 60–90 seconds
- Lowers cortisol levels
- Increases oxygen delivery to the brain
- Shifts you from reactive to deliberate thinking
- Reduces perceived pain and discomfort
Navy SEALs use it before high-stress operations. Surgeons use it before complex procedures. Athletes use it between rounds. You can use it between evolutions, between sets, or any time your brain starts working against you.
How to Do Box Breathing
Step-by-Step
- Find a comfortable position — seated or standing, spine straight
- Exhale completely to empty your lungs before starting
- Inhale through your nose for a slow count of 4
- Hold your breath for a count of 4 — don't clamp down, just pause
- Exhale through your mouth for a count of 4 — slow and controlled
- Hold at the bottom for a count of 4
- Repeat for 4–6 full cycles
The Count
Each count should be approximately 1 second. So one full box = 16 seconds. Four cycles = about 64 seconds. In under 2 minutes, you can meaningfully shift your physiological state.
Beginner Modification
If 4-4-4-4 feels too long at first, start with 3-3-3-3 and build up. The goal is slow, controlled breathing — not holding your breath until you're dizzy.
When to Use Box Breathing
Box breathing is most powerful when used consistently — not just in crisis moments. Here's when to deploy it:
- Before a hard training session — prime your nervous system for performance
- Between sets or rounds — recover faster and maintain output
- During the Murph — between rounds of 5/10/15 to keep heart rate in check
- Before a PST or selection event — calm pre-performance nerves
- During cold water exposure — the instinct is to gasp; box breathing overrides it
- When your self-talk turns negative — breathe first, then redirect
- Before sleep — downregulate after hard training days
Box Breathing in Hell Week
I used box breathing during my second Hell Week. When the cold got unbearable, when the sleep deprivation made everything feel impossible, when my brain started building exit strategies — I breathed.
Four counts in. Hold four. Four counts out. Hold four.
It doesn't make the cold go away. It doesn't make the pain stop. What it does is give you back control of your mind for the next 60 seconds. And in Hell Week, 60 seconds is enough to keep moving.
"You can't always control what's happening around you. But you can always control your breath. And your breath controls everything else."
— Coach Brad McLeod
How to Build Box Breathing Into Your Training
Don't wait until you're under stress to practice this. Build it into your daily training now so it becomes automatic when you need it most.
- Morning practice: 5 minutes of box breathing before your first workout of the day
- Between hard sets: 1–2 cycles of 4-4-4-4 during rest periods
- Cold exposure: Practice during cold showers or ice baths — this is the closest training simulation to surf torture
- Pre-sleep: 4–6 cycles before bed to improve sleep quality and recovery
Build the Complete Mental and Physical System
Box breathing is one tool in the SGPT mental toughness toolkit. Every SGPT program is built to develop both the physical engine and the mental operating system that runs it.
🔥 SGPT Silver On-Ramp Program — The foundation. Builds physical fitness and introduces the mental toughness practices — including breathing techniques — used in every SGPT program.
💪 SGPT 365 Total Training System — A full year of operator-level programming. Mental toughness is built into every phase — not added as an afterthought.
🏋️ Tier 1 Development Program — Advanced 90-day tactical fitness. This is where your mental tools get tested at the highest level.
🎯 SGPT Murph Challenge 2026 — Memorial Day is 12 days away. Use box breathing between Murph rounds. Practice it now so it's automatic on May 25th.
Control your breath. Control your mind. Control the outcome.
HOOYAH!
Coach Brad McLeod
Former Navy SEAL | Founder, SEAL Grinder PT & SGPT Online
SEALgrinderPT.com