"I wasn't breathing in my sleep," Fielder said. "They gave me a mask so I could sleep. They said if you stop breathing 30 times an hour while you're sleeping, that's extreme. I was at 39."
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An estimated 18 million Americans, or 6.62 percent of the population, deal with sleep apnea. Former Ranger Mike Napoli had a severe case of sleep apnea that he finally overcame a couple of years ago.
"My wife told me I always snored loudly and stopped breathing in my sleep," Fielder said. "You don't feel it as much when you're young, but as you get older, it affects you more.
"I wasn't panicking, but I wanted to make sure. I was sleeping, but I didn't feel rested. Now that I know, I can sleep through the night. My wife can sleep, too, since I don't snore."
Napoli had to have his jaw broken to fix the problem.
"I don't think so," Fielder said. "I think I will stick with the mask."
Fielder is expecting that a better night's sleep will translate to better performance on the field.
"Believe it," Fielder said. "Believe it."
• Infielder Rougned Odor, sidelined with a sore right oblique muscle, is taking ground balls, but he is not yet ready to swing a bat.
• First baseman Ike Davis has been fitted with a brace on his right knee and is still day to day with a mild sprain.
T.R. Sullivan is a reporter for MLB.com. Read his blog, Postcards from Elysian Fields, follow him on Twitter @Sullivan_Ranger and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.