Harley Pasternak is the personal trainer behind some of Hollywood's most impressive physiques but you won't find him promoting fad diets or grueling exercise regimes. The Canadian fitness expert opened up to HELLO! in an exclusive chat in which he revealed the remarkably down-to-earth ways he whips the likes of Ariana Grande, Jessica Simpson and Megan Fox into tip-top shape - and the great news is you can do it too!MORE: Jessica Simpson reveals incredibly toned body in lycra workout gearSpeaking