Alongside F1’s longest-ever season of 21 races, the Spaniard will contest the full world endurance championship, including fabled Le Mans.
Asked if at the age of 36 it might be too much, Alonso laughed to Marca sports newspaper: “No, I’m not grey yet.
“Seriously, I’m physically well. Ok, ten years ago facing a challenge like this would have been very difficult or even impossible or a mistake.
“But now I am 100 per cent sure I can face it. With the way I know formula one, other categories like the Indy 500, even the way I need to travel, I’m ready now.
“That’s why a programme like this has never been done,” Alonso explained. “It’s almost impossible. Only at certain moments of your sports career, such as where I am now, can it be done, and then not everyone can do it.”
Indeed, Alonso was speaking from his latest Toyota LMP1 test, having just been at McLaren’s Woking factory to see his new F1 car.
“This year it will be important to have every detail clear,” he continued.
“Now, the whole year will have to be designed almost day to day to get to November for the last grand prix in a very strong condition.”
Meanwhile, Alonso declined to comment on the account of a former McLaren mechanic, who confirmed that back in 2007, Ron Dennis wanted Lewis Hamilton rather than the Spaniard to win the title.
“One story always comes out and then another follow it,” Alonso said.
“It’s a long time ago and water under the bridge but we all saw what happened. But when my book comes out at the end of the year, you will read everything.”