You've probably heard -- or repeated -- these Colorado myths: 'beer impacts you more in the Mile High City' or ‘despite the amount of sunscreen you use – you’ll still get burned.'

Well, it turns out, there's still some truths to these sayings.

Marte Meyer, P.A.-C, MBA, and vice president of 9HealthFair, set the record straight – but, before talking about beer and sunburns, we have to talk about altitude.

Meyer has been a physician’s assistant for 40 years -- many of those years in Colorado. He says there are some physiological changes you go through when you move from sea level to somewhere 5,000 feet or higher.

For example, your red blood count will be higher, the cells that carry oxygen in your blood stream will also be higher. There’s about 9 percent less oxygen at 5,000 feet than at sea level. Meyer says your body has to compensate for that oxygen level – which could equal you needing more sleep and drinking more water.

As far as beer goes, Meyer says the physiologic effect on your brain is the same whether you’re at sea level or if you’re at altitude.

He says “the difference is, at altitude, your body is having to work a little bit more to make sure you’re actively ventilating, you’re getting all the blood to your organs, and so anything that causes a degradation in your mental status, can impact that a little.”

“It’s really important, because you’ll hear when people go skiing out here we tell them – drink, drink, drink, drink and I don’t mean booze, I mean water," he said.

Meyer says it’s much easier to have problems if you’re dehydrated, so drinking lots of fluids and lots of water is going to lessen the impact of hangovers – or alcohol’s effect on the body.

“There’s a little bit of truth to the altitude myth – it’s not really a myth, we know there are physiologic changes to your body," he said.

The bottom line? There’s more strain on your body at a higher altitude.

When it comes to sunburns, if you wear sunscreen, you won’t get burned and you’ll be protected from UVA and UVB rays. However, you could develop a Vitamin D deficiency.

Meyer says it’s good to wear sunscreen – but also be aware that you need to get some sun. He says “one thing we’re experiencing in Denver and other places is that during the winter, and even during the summer, people are using so much sunscreen and covering up, and you need sunshine to make Vitamin D.”

The 9Health Fair does offer Vitamin D testing to make sure you have yours at an okay level.

So what do you do? Go outside without sunscreen and risk the burn? Meyer says the answer is simple: do it in moderation.

“A little bit of sunshine is okay, but because of the altitude, there is not as much atmosphere between us and the sun, so it’s not filtering as much of those UVA and UVB rays so they’re hitting your skin more frequently than you would at sea level," he said.

The myths are pretty much truths in this case. Colorado is such an outdoorsy state, people are outdoors all the time, so exposure to the sun and the effect of altitude on your body is all related.

He says, keep staying active, keep a healthy weight, and you’ll be better off in the long run.