Josh Duhamel has started testosterone replacement therapy so he can "stay young" for his wife

He told Men's Health Lab: "It's important for her that I stay as young and virile for as long as I can.

"I think that there is an overall wellness, you know, just for just for those purposes alone...

"Just having that energy, that that that desire to go out and achieve, be a better dad, be a better brother, be a better friend, be a better business owner, you don't taper off like you would normally-and I think that that's also one of the benefits of it, mentally and physically.

"I'd been hearing about this for a while-about testosterone replacement therapy-and it was one of those things that I didn't want to talk about, neither did anybody I was asking about it.

"And I think that it was just, I took an inventory, a personal inventory, of how I was feeling, and I knew that I wasn't quite where I was at five, 10, years before. That's when I got myself tested, and realized my levels were low, and that's when I decided to start doing it."

The Transformers star - who was previously married to Black Eyed Peas singer Fergie and has 11-year-old son Axl with her - has got his "mojo back" with his new tratement, and has found that it is all about "being around for [his] kids" and still being able to do things with them as he get older.

He said: "It's just one of those things that just changed my world. I literally got my mojo back. And now it's become, not so much about the aesthetics of it, as much as it is being around for my kids and being able to roll around the dirt with them like I could have when I was younger."