Lemar says his new single is not a comeback.
The singer, 34, released four albums, sold two million records and won a clutch of awards after coming third on Fame Academy in 2002.
His new single, Invincible, comes four years after his last album.
But asked whether it felt like a comeback, he said: "Not so much, because I had my Hits album out about 18 months ago, but I've been busy doing a lot of writing, so that makes it feel like the wheels have been turning."
The singer said it had "been a while" since he had performed in front of people.
He said: "I have to get out there and remind people what I'm about and who I am."
Lemar added: "It all feels new again, but when you get on that stage it soon comes back to you. It's an amazing feeling.
:: Lemar's new single, Invincible, is released on August 12