AUTHORS Geert De Lombaerd

Shares of Tivity Health popped nearly 10 percent after hours Tuesday after executives of the fitness programs company said they have extended their SilverSneakers contract with Humana, which accounts for about 15 percent of its top line.

The deal for senior fitness services had been scheduled to run through 2020 but has now been extended through the end of 2022. Tivity’s contract gives Humana’s 3.3 million members and future enrollees access to SilverSneakers, which is available to 15.8 million people across the country.

“We share a common mission with Humana to provide seniors with opportunities and resources to improve their overall health so that they can live their best lives,” said Donato Tramuto, CEO of Tivity, which first signed on Humana in 2004 when it was still American Healthways. “Studies show that loneliness and social isolation can shorten one’s lifespan by as much as eight years. We are proud to partner with Humana to offer a program that enables healthier aging by providing seniors and others with Medicare both physical activity and social connection.”

Tivity shares (Ticker: TVTY) rose to $39.85 after hours after closing the regular session at $36.30. If they hold that level Wednesday, it will be their highest since early November, when word that UnitedHealthcare  — Tivity’s other 10-plus percent-of-revenues customer — planned to broaden its fitness program offering hammered them by more than 30 percent.