IT’S the summer of 1963, and 17- year-old Frances ‘Baby’ Houseman is about to learn some major lessons in life as well as a thing or two about dancing.

On holiday with her older sister and parents, Baby shows little interest in the resort activities, and instead discovers her own entertainment when she stumbles across an all-night dance party at the staff quarters. Mesmerised by the raunchy dance moves and pounding rhythms, Baby longs to be part of the scene - especially when she spies Johnny Castle, the hunky resort dance instructor. When she’s suddenly thrown in at the deep end, as Johnny’s leading lady - on and off stage - the teenager’s life changes forever.

Perennial favourite Dirty Dancing is a show that requires a highly skilled cast of dancers. And for 31-year-old Lewis Griffiths, who plays Johnny Castle in the tour, it’s all about keeping up the strength and stamina.

How does he warm up for a show? “I start with shoulder rolls and chest stretches before moving on to my legs. I’ll always do quadricep and hamstring stretches, and as many ankle rolls as I can to help mobilise the joint,” says Lewis. “Everything from the waist down needs to be limber because the entire show involves bent legs, hip rolls and thrusts - it’s dirty dancing after all, you can’t do it with locked knees and straight legs!”

As any leading actor in a touring production knows, fitness is the key - and with Dirty Dancing being such a physical show, Lewis has to keep in prime condition to perform eight shows a week. “Beyond sleep, water and green veggies, I’m a fan of wheatgrass. I’ve heard one small shot of wheatgrass is the equivalent of a kilo of green vegetables, so I recently started taking them,” he says. “The results are amazing; I’m more energised and have better skin. Also massage is a must for me - sometimes I’m so tight I can barely stretch; I need a professional to loosen it off and remove the lactic acid. I’ve had a couple of reflexology treatments recently too and I practice Tai Chi about once a week.”

Does he keep fit when between jobs, or is the temptation to relax a little? “When I’m on a job I go full throttle and when I’ve finished I let go a bit,” he says. “Before Dirty Dancing I was eating too much chocolate and not going to the gym. I had just four weeks before rehearsals to wake my body up, so started doing something every day, be it five-a-side football, weightlifting or jogging.

“The biggest issue when I’m working is keeping weight on! On the last job I did we were all in suits and the wardrobe mistress kept telling me off for losing too much weight! My metabolism was so ramped up from all the movement I had to supplement my diet with protein.

“In terms of meals, I always eat breakfast, something like porridge, blueberries and banana, or toast with green tea. If I have time to cook it’s scrambled or poached eggs on toast with spinach and asparagus.”

And, he reveals, keeping a clear mind is as important as physical health. “If I’m feeling tired and lacklustre, I’ll remind myself that one audience has paid the same money as the next one so it’s not fair to let standards slip. I’m fairly philosophical in my approach; I believe in forgiveness and that you reap what you sow. I remind myself that it’s live theatre, I’m only human but if I put in the time, effort and nurture and make the most of every opportunity then I’ll get the best out of it.”

l Dirty Dancing runs at the Alhambra from May 1-6. Call (01274) 432000.