Sam Heughan works out ''every day''.

The 37-year-old actor has admitted he has an intense fitness routine, but because of his hectic work schedule, which sees him jet off across the globe, he sometimes struggles to find the time to keep fit.

Speaking to the Metro newspaper about his exercise plan, the Scottish hunk said: ''Probably every day.

''It's tough [to stay in shape] because I travel a lot.

''I'm really into a healthy lifestyle''.

And Sam - who portrays Jamie Fraser in the popular series 'Outlander' - has been able to ''relax'' his fitness regime recently because he has not needed to go topless in the programme recently.

He added: ''The last few months I've relaxed a bit because I didn't have to take my top off for the show or a magazine shoot.''

And the star ''dreads'' having to strip off for scenes because he has to undergo a lot of preparation in advance, and then has to sit for ''three hours'' to have a prosthetic piece attached to his back.

When asked if he feels a pressure to look good,he said: ''We have to prepare for those [topless] scenes. I dread them more because I have a full prosthetic on my back, which takes two to three hours to put on.''

The 'A Princess for Christmas' star set up the charity My Peak Challenge to raise funds to advance research for diseases such as leukaemia and lymphoma, and the programme includes a daily workout and meal plan for its subscribers.

Speaking about the foundation, he said: ''I created a charity fundraiser a couple of years ago called My Peak Challenge. We now have raised almost £375,000 for leukaemia and lymphoma research. We supply almost 10,000 subscribers with a daily workout and meal plan. ''

And the star has revealed his fans have backed his project.

He said; ''They get behind our charities, which is really rewarding.''