Sumner Redstone may be nearing 92, but he still isn’t ready to retire.

Speculation over the health of Redstone, who controls both CBS Corp. and Viacom Inc. through his family’s movie-exhibition company National Amusements Inc., has only grown in recent years as he’s has gotten older and has become less of a presence at the companies’ New York headquarters and on their quarterly conference calls with investors. In an email exchange with Vanity Fair writer William D. Cohan, however, the media mogul says he remains deeply involved with both companies and is still able to follow a daily routine.

“I still get up at 4:30/5 a.m. every day I ride my bike and go to the pool and get a haircut. I’m really into watching sports,” Redstone said in the electronic conversation.

Viacom executives told Cohan that Redstone remains “sharp as a tack” and that his memory is keen. But other sources to whom the author spoke suggested Redstone is in a weakened condition and requires help throughout the day.

“You should know that I am never retiring!!!” Redstone told Cohan.  What’s more, the executive said he expected to attend CBS’ annual shareholder meeting in New York later this month.