Heart racing, palms sweating and breath quickening? You’re not alone.

Stress and anxiety may be part of modern life, but for millions of Americans, these occasional mood killers have become daily struggles — and it’s not just younger generations feeling the pressure.

Gallup’s 2025 Global Emotions Report found that nearly half of US adults feel significant stress every day, while more than a third report frequent worry.

Left unchecked, it can take a serious toll on quality of life, fueling persistent irritability, burnout, feelings of hopelessness and an increased risk of depression.

It can also ripple into everyday functioning, raising the risk of social isolation, poor sleep, unhealthy lifestyle habits and a reduced ability to cope with basic daily demands, sometimes making it harder to keep up with work or even routine tasks.

Dave Asprey, the self-proclaimed “creator of the biohacking movement,” knows that reality firsthand.

“I used to weigh 300 pounds, and I actually was full of anxiety, chronic fatigue syndrome, all sorts of unfortunate mental, emotional and physical issues,” the longevity expert said on an episode of the “Covenant Eyes Podcast” last year.

“I’ve been on a 25-year journey of repairing my hardware and rewiring my nervous system and my mind.”

Asprey breaks down what he’s learned in his ninth book, “Heavily Meditated: The Fast Path to Remove Your Triggers, Dissolve Stress, and Activate Inner Peace,” released in 2025.

While some of his more extreme methods — from psychedelics to neurofeedback training — may not be accessible to everyone, he says there are also simple, free tricks that can help calm the mind.

Asprey shared two of his go-to strategies with The Post for shifting the body out of “fight-or-flight” mode and into a calmer “rest-and-digest” state, so you can ease anxiety quickly at home or on the go.

First up: Box breathing

“Changing the way you breathe can change your entire state in a matter of minutes,” Asprey said. “Box breathing is one of my favorite ways to move out of fight-or-flight mode.”

Don’t just take his word for it. Soldiers, police officers and even professional athletes use the same technique to stay calm under pressure when anxiety strikes.

Here’s how it works:

• Find a quiet spot where you can sit upright comfortably, feet flat on the floor.
• Inhale slowly and deeply through your nose for a count of four, letting your lungs fully expand.
• Hold your breath for a count of four, keeping your body relaxed.
• Exhale slowly through your mouth for a count of four, fully emptying your lungs.
• Hold again for a count of four.
• Repeat the cycle three or four times.

If your mind starts to wander, picture a box and mentally trace its edges as you breathe — it can help keep your focus and rhythm steady.

The exercise calms the sympathetic nervous system, which drives the physical symptoms of anxiety.

When activated under stress, the network of nerves releases adrenaline and cortisol, which can trigger a racing heart, shallow breathing, muscle tension and sweaty palms, among other effects.

At the same time, box breathing activates the parasympathetic nervous system, which is responsible for winding the body down after stress, shifting you into a calmer “rest-and-digest” state.

One study found that several breathwork techniques, including box breathing, can help reduce anxiety and improve mood.

A review of 15 studies showed that slow breathing exercises may improve emotional control, overall well-being and psychological flexibility.

Research has also linked breath regulation to lower blood pressure and cortisol levels.

Next: Take the plunge

While Asprey’s first strategy calms the body down, his second delivers a shock to the system.

“Get a salad bowl about as big as your face, put an inch of water in the bowl and put it in the freezer overnight,” he advised.

“Before you go to bed, take it out of the freezer and add about 3 inches of cold water to the bowl. Then, take a deep breath and stick your face in the ice water.”

Asprey said most beginners can only last about eight seconds before the cold becomes too intense. But with repetition, tolerance builds.

“Put the bowl back in the freezer for the next night, and the next day you’ll go 30 seconds,” Asprey said. “And then the third day, you might make it up to a minute, if you can hold your breath that long. If not, just use a snorkel.”

The trick might sound extreme, but there’s some science behind it.

The cold plunge, Asprey explained, stimulates the vagus nerves, which run from the base of the brain down through the neck and into the chest and stomach.

They play a key role in the body’s “rest-and-digest” response, helping regulate heart rate, blood pressure, breathing, muscle tension, mood and even the gut.

“When you have good vagus nerve tone, you’ll be calm, your digestion will be smooth and you’ll recover more quickly from everything,” Asprey said. 

You don’t have to save it for bedtime.

In a moment of panic, plunging your face into ice-cold water — or even splashing some on the back of your neck — can act as a quick reset, helping to cool the body down, slow the heart rate and settle an overactive nervous system.