Optimum Nutrition Casein Protein Powder

Recover strong and rest easy with the best casein protein in New Zealand.
From Optimum Nutrition Casein to Muscle Nation and Rule 1, these slow-release proteins fuel overnight recovery and help maintain lean muscle mass between meals. Rich in essential amino acids and designed for sustained absorption, casein is ideal before bed or during extended periods without food.

Shop premium casein protein brands at the best prices — only at Sprint Fit.

About Optimum Nutrition 

Over 35 years, Optimum Nutrition’s obsessive pursuit of the highest quality standards has only been matched by the desire to see you achieve your goals.

Powering 2 billion workouts around the world, Optimum Nutrition has helped anybody who ever had a fitness aspiration and believed that they could achieve it, from elite athletes to everyday gym goers and amateur sportsman.

Banned substance tested & trusted by fitness professionals. Optimum Nutrition remains the #1 protein brand in the world for a reason.

Sprint Fit stocks a wide range of Optimum Nutrition products such as the multi award winning 100% Whey Gold Standard Protein, Serious Mass, Amino Energy and Gold Standard Pre Workout. Order your Optimum Nutrition Amino Energy supplements from Sprint Fit today and be in to win a 1 of 5 Rainbow prize packs!