When was the last time you walked barefoot in the park? What about on the beach, or in your backyard?

It seems like a simple concept, but direct (skin) contact with the surface of the earth actually has powerful, life-changing health benefits. And no, this isn't just for "hippies" — there's some hard science backing it up.

Related: These Super Herbs Fight Stress, Give You Energy, and Promote Weight Loss [1]

The concept is called earthing, also referred to as grounding. And, as mentioned, it's simple: skin-to-earth contact. Your body receives energy and free electrons directly from the earth — kind of like how we receive energy from the sun, but this terrestrial energy comes from actual, physical contact.

Board-certified cardiologist and certified bioenergetic psychotherapist Dr. Stephen Sinatra is essentially an earthing evangelist and raves about the benefits of grounding [2] in his video describing the concept. He calls it "caveman medicine," which might resonate a little more with you Paleo dieters out there!

Dr. Sinatra also published his findings in a 2013 study [3] about the powerful effects earthing has on the cardiovascular system . . . which leads us into the good stuff: what are all the benefits? Let's take a look.

• More energy. One of the more instant benefits you'll feel from earthing is a surge of new energy. This 2015 study [4] referred to contact with the earth as a "battery."
• Less stress. Anxious and stressed out [5]? Grounding can help with both of those things — even chronic stress. Dr. Sinatra mentions you'll have "more tranquility in your system."
• Better sleep. Struggling to get your zzz's? Take a barefoot walk in the grass. Science supports it [6].
• Cancer prevention. By "soaking up millions of free electrons [from the earth], that can intercept free radicals," as Dr. Sinatra put it; you're reducing your risk for cancer.
• Healthier blood. Dr. Sinatra's study cites that grounding can thin the blood [7] so it doesn't become coagulated, thus preventing disease.
• Reduced pain. One study stated [8] that contact with the earth can be "a profoundly effective environmental strategy" against pain and common health disorders.
• Reduced inflammation. Similarly, by earthing, you can treat chronic inflammation. The researchers at the Journal of Inflammation [9] said earthing and grounding can be a "simple, natural, and accessible health strategy against chronic inflammation, warranting the serious attention of clinicians and researchers."
• Better mood (and metabolism!). A 2011 study pointed out that earthing could be "the primary factor regulating endocrine and nervous systems." Refresher course: the endocrine system regulates mood, sex drive, and metabolism. The ANS [10], or autonomic nervous system, regulates organ function, including intestines. It could be inferred that by this regulation, you'd have improved digestion as well.

Ready to get started? Dr. Sinatra and several studies have referred to grounding and earthing as the "most primitive, easiest, cheapest way to create optimum health." It costs nothing to try it out, and really, what harm is there in taking a barefoot walk in the park, strolling shoe-less along the beach, going surfing, or taking your shoes off in the backyard?