Dave Asprey is a professional biohacker. The Silicon Valley entrepreneur has spent nearly two decades, and hundreds of thousands of dollars, learning how to increase his body’s performance and resilience.

That’s meant everything from founding a company, Bulletproof, which makes brain-boosting supplements and equipment, to growing new brain cells through stem cell injections.

You don’t have to devote your life to improving your brain’s performance, though. In his new book, “Head Strong” (out Tuesday, $27.99), Asprey shares what he’s learned about improving brain function — specifically focusing on mitochondria, the “powerhouses” of cells that produce energy — with minimal effort.

“When I talk to people, it’s an epidemic — ‘I just can’t pay attention,’ ” Asprey said. “We’re all struggling, and partially it’s because we don’t eat the right stuff, or don’t exercise, or exercise the wrong way.”

If you find yourself experiencing “brain fog,” Asprey shares three ways you can improve your brain power right now.

1. Take a cold shower for up to 1 minute.

Cold therapy has been shown to stimulate the creation of new, healthy cells as well as reduce inflammation and burn fat. But you don’t have to necessarily sit in an ice bath or do cryotherapy. A blast of cold water at the end of your shower can have a similar effect, Asprey said. “The first time you do it, the first 10 seconds will feel really bad,” he said. But after a few days, “You’ll have more energy all day long and it will help you sleep better.”

2. Exercise less — in the right way.

“There are two types of exercises that are the most effective at making your mitochondria work better,” Asprey said. One is walking every day for 20 minutes; the second is doing 10 to 15 minutes of intense exercise once a week, such as high-interval sprints or heavy lifting. “This is how you get the most out of your ‘battery’ and make your body regenerate itself for the longest,” Asprey said.

3. Get rid of excess light.

There are a few ways you might be decreasing the quality of your sleep. “One of the things that is so common is, before we go to bed at night, we look at our phone,” Asprey said. “It’s turned up to full brightness, and we have LED lights in our bedroom, and unfortunately all of those things stress the mitochondria in your eyes, and your eyes are a part of the brain.” Avoiding bright lights before bed, dimming the brightness on your phone, installing blackout curtains and putting tape over LED lights in your home can help. “They’re simple behaviors and are not expensive, but they can have a profound effect on your energy output,” Asprey said.