Sleep apnea at high altitude a hidden hindrance for endurance athletes | SummitDaily.com

Sleep apnea at high altitude a hidden hindrance for endurance athletes

For athletes, a good night's rest is more than a luxury — it's a must.

But, a good night's rest isn't always so simple at 9,000 feet in Summit County. For about five years, local doctor Warren Johnson thought he was sleeping just fine until he noticed his blood pressure was rising, slowly but surely. He couldn't place his finger on the cause — he leads a healthy lifestyle between diet, fitness and general wellness — but he knew something was behind the spike.

"I realize in retrospect that I wasn't sleeping well," he said. "I would see the clock almost every hour — I just didn't remember it."

Until recently.

After dedicating the past few years to studying the effects of altitude on the heart, Johnson found that he had developed sleep apnea. In general, sleep apnea is a breathing disorder that impacts your airway at night and, in turn, your entire sleep cycle. Folks with the disorder repeatedly stop and start breathing, sometimes going upwards of 90 seconds without a single breath. It can lead to snoring, insomnia and restlessness at night, plus depression, headache and outright fatigue during the day. Think of it as sleeping on an airplane — it's just not quality rest.

Sleep apnea comes in two forms: obstructive sleep apnea, which leads to snoring and can affect just about anyone; and central sleep apnea, which tends to impact people who live at altitude. One common device for diagnosis is an overnight oximeter, which monitors the level of blood oxygen as you sleep.

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Johnson knew that a lack of sleep can lead to pulmonary hypertension (aka high blood pressure in the lungs), and that's when the bulb went off. Soon after making the connection, he used and overnight oximeter and found his oxygen levels were much lower than he wanted. He then started sleeping with oxygen at night and watched as his pulmonary pressure dropped from a high of 45 mmHg to 23 mmHg, lower than the benchmark of 30 mmHg.

"I think it's important that athletes or anyone — I think everyone should do this — can use oxygen at night," Johnson said. "If someone wants to know what's happening, wants to know more about their physiology at night, this can help."

The athlete connection

Like a good night's rest, proper blood pressure and heart rate are vital for athletes, especially endurance runners and cyclists who live and compete at altitude. No matter what, strenuous exercise will take a toll on your body and sleep is the best, most natural way to replenish.

"When you sleep, you get tissue repair, muscle growth and protein synthesis," local trainer Julie Wilson said. "It's important to have enough sleep to recharge your entire body."

And that's where central sleep apnea can throw a wrench in the physiological gears. Take, for example, an endurance athlete preparing to compete in the Run the Rockies Half Marathon on June 4. The course from Copper to Frisco never drops below 9,000 feet — the threshold when your body is constantly fighting against anaerobic exertion — and at least 9-10 hours of sleep before the morning start time is ideal.

But, if you're fighting an unknown battle with sleep apnea, 10 hours of rest the night before won't always equate to a full 10 hours. Instead, your body is already struggling with the effects of altitude, and you haven't even laced up your shoes.

"If you have a race or an event coming up, sleep can improve your reaction time and reduce injuries," Wilson said. "Your body needs this anytime you're working hard. If you don't, your body just won't recover."

A simple fix like sleeping with oxygen can be the answer, Johnson said, but he recommends first seeing a doctor to determine if it's impacting your performance on the trail.

"It's very subtle," he said of central sleep apnea, "But, if athletes are interested in evaluating their performance at altitude, they should consider overnight oxymetry."