Chris and Tom Roche, who train at Bodyflex Gym in Aylesbury, competed at the NPA Midlands Championships last week and both got second places against tough opposition.
It means the brothers qualified for the nationals on October 28.
Bodyflex owner Tony Montalbano said: “Im very proud of them especially Chris who is only 18!”
Now in its ninth year, the NPA promotes the sport of Natural Bodybuilding in the UK and has five qualifying competitions all leading to the NPA British Championships.
A spokesman for the organisation said: “All our shows are drug tested to WADA standards. We are here to inspire you to create the best body you can by following a Natural Bodybuilding lifestyle. Bodybuilding/weight-training can improve your life in a huge way, and not just physically, you’ll find your mental strength and self-belief will benefit too. Train hard, stay healthy and Natural, and support the NPA.”
Visit the official NPA website