According to award-winning comedian David Walliams, Luton sports supremo Greg Whyte changed his life.  In a glowing foreword to Greg's first book - Get Fit Not Fat: 150 Ways To Build Fitness Into Your Life - he says: "Maybe he can change yours, too." 

The Little Britain star writes: "After meeting my comedy partner Matt Lucas, meeting Greg was the most fortunate meeting of my life. 

"He proved to be a huge fountain of knowledge about every aspect of sport and fitness.  Anyone wanting to improve their health and fitness will learn so much from Greg's intelligent and yet simple and straightforward advice." 

With obesity the current buzz word and combating it a government priority, the former Ashcroft High pupil's timely tome could not be more appropriate. 

Greg, who now chairs the school of applied sport and exercise sciences at Liverpool John Moores University, felt the time was right to address various health issues and promote an active lifestyle. 

He says: "We're constantly bombarded with the diet message and led to believe that fat is the major problem society faces.  The simple fact is that inactivity causes obesity. 

"Exercise offers so many benefits.  Not only does it enhance quality of life, but it also has the positive effect of reducing the incidence of death from more than 20 chronic diseases." 

The recommended target is 30 minutes of exercise five times a week but in today's busy world it can be hard to find the time.  Drawing on his experience, the one-time Olympic champion shows how exercising in shorter bouts is just as effective. 

Get Fit Not Fat took Greg a year to write - in between hitting the headlines with his work for Sport Relief and training for The Race Across America, in aid of his adopted charity Cardiac Risk in the Young (CRY).  It is simple to follow and well laid out with lots of photographs and illustrations and induces chapters on structuring workouts and motivating yourself to exercise. 

There are sections on core strength and stability, bum, tum and thighs, strength and power, band exercises and flexibility as well as five, 10 and 30-minutes workouts. 

The book looks set to become the 21st century fitness bible. 

It was Greg's idea to write the book, which he says was a "fantastic experience".  He is already in discussions about a follow-up.

Get Fit Not Fat: 150 Ways To Build Fitness Into Your Life, by Greg Whyte, is published by Kyle Cathie Limited and costs £14.99.