(Bloomberg) -- Fitness firm F45 Training Holdings Inc. is having its best session of the year so far after giving a bigger role to early backer Mark Wahlberg.

The actor and singer will become F45’s chief brand officer effective immediately, the company announced on Thursday. Shares surged as much as 24% on the news in their biggest jump since Sept. 30.

Wahlberg, who’s cultivated a macho persona through his portrayals of boxer ‘Irish’ Micky Ward in The Fighter and extortionist gym instructor Daniel Lugo in Pain & Gain,  has been on the company’s board since 2019. He bought a pre-IPO stake in the firm that year at a valuation of roughly $450 million. The firm now has a market cap of $140 million, according to data compiled by Bloomberg, with shares trading 91% below their 2021 IPO price of $16.

F45 also announced that GNC Holdings Inc. veteran Tom Dowd would succeed interim CEO Ben Coates. The new chief brings a health and franchising background to the company, but short-term financial visibility remains extremely low, Baird analyst Jonathan Komp wrote in a note. 

“The release notably gave no update on the current timeline to report Q4/2022 financials, with tomorrow marking the 15th day since FXLV filed its delay notification for the 10-K filing on 3/16,” it says.

--With assistance from Katrina Lewis and Ben Stupples.

©2023 Bloomberg L.P.