Even at our cleanest, we are covered in germs and we are full of germs. It's ok! That's totally normal. These microorganisms are essential to our health. You probably don't need to mess with them, but if you'd like to try, the terms to know are prebiotics and probiotics.

Cannabidiol, the non-psychoactive component of cannabis, is developing a reputation as a trendy cure-all. But science knows very little about what it does in the human body, so much about the workings of this drug - including whether it works at all - is something of a mystery.

If you've ever flown in an aeroplane, you've heard the spiel about the oxygen mask. If you looked up from your phone, you've even seen a flight attendant demonstrate exactly how to put it on. And yet, people on the recent Southwest flight still got it wrong.

Many of us have done a little bit of Pilates at some point; Pilates-style moves are found in plenty of workouts that incorporate yoga or bodyweight exercises. But it's another thing to step into an actual Pilates studio and find yourself face-to-face with the famous reformer.

Weed is famous for its ability to relieve nausea, but it can have the opposite effect in people who smoke a lot of it. The little-known condition, called cannabinoid hyperemesis syndrome (CHS), involves bouts of extreme nausea, vomiting, and stomach pain, and can be temporarily relieved by a hot shower.

That sneeze in the elevator. The snot somebody wiped on that handrail an hour ago. Your coworker who won't stay home, breathing right next to you. Cold and flu viruses are everywhere. And if you're coming down with something, you're spreading them too.

You shouldn't give your dog your leftover chicken bones because they can break into splinters. You shouldn't give them large raw bones because they can be full of germs (and if they weren't at first, they will be once your dog has dragged them all over the yard). Now, more bad news: The FDA says store-bought dog bone treats are dangerous, too.

Now that we're almost two weeks into our plank challenge, you've probably figured out that some kinds of planks feel harder than others. Tiny changes in your body's position can make a big difference.

It would be terrifying if baby wipes caused food allergies, right? Good thing we have zero evidence of that (phew). A recent study was reported as if this is the answer to why everybody's allergic to peanuts, but guess what? The study didn't prove that. And it didn't involve baby wipes. It didn't even involve (human) babies.

Video: It's a modern paradox that we only get the freedom of flying through the air when we are squeezed shoulder-to-shoulder with other humans for the duration. But you probably have a little wiggle room in that seat, and doing some exercises can help relieve that cramped feeling.

If there's a study that shows pasta in a good light, it's hard to ignore. Everybody loves pasta, right? I do. Chances are you do, too. Barilla, maker of pasta, definitely does.

We recently wrote about why skincare is important, and what you need in a basic routine. Our sources stressed that everyone, even men, should use sunscreen daily, and usually moisturizer, too. But one commenter piped up to ask: uh, what if I have a beard?

Plank may not be easy, but it's simple. If you're getting bored, though, there are other ways to do it! Here are some variations to try as we enter the second week of our plank challenge.

If you use a wheelchair, or other kinds of mobility aids or medical equipment, you might find people staring at your gear instead of looking at you. Elsie Tellier has two fantastic videos about how to dress up yourself and your gear, whether it's to reorient people's eyes or just to have fun.

LDL used to be the "bad cholesterol" and HDL the "good cholesterol." That's the tidy story I learned in my grad school lipids class 13 years ago, but the science has evolved since then. High HDL is no longer automatically good, for example. Let's take a look at what your cholesterol numbers really mean.

Zero exercise is not enough. Going for a walk every day is probably a good thing. And if you're training for a marathon, you'll be on your feet for a couple hours of hard workouts every week. But what is the benchmark for a human being just trying to squeeze enough healthy exercise into their life? Let's break it down.

Well, folks, we've come to the final day of the March flexibility challenge. How did it go?

When somebody gets a traumatic injury like a gunshot, it's often not the trauma itself that kills them, but blood loss. In honour of yesterday — Stop the Bleed Day — read on for the basics everyone should know.

Dear readers, I'm sorry. When I asked Lifehacker staffers what's been missing from our fitness challenges, the resounding answer was that we all need to spend a month working on our plank game.