Rule 1 R1 Casein is a premium, slow-digesting protein powder engineered to supply your muscles with a steady stream of amino acids throughout the night. Formulated with 100% pure micellar casein, this overnight recovery formula breaks down gradually over several hours to help prevent muscle tissue breakdown during extended periods of fasting. Designed for hard-training athletes and active Kiwis looking to optimize 24-hour muscle repair, Rule 1 R1 Casein ensures your body stays nourished and primed for recovery long after you turn off the lights.

Key Benefits & Features

• 100% Micellar Casein Source: Made exclusively with premium micellar casein for slow, sustained amino acid release with zero inferior protein blends.

• Sustained Nighttime Anti-Catabolic Support: Feeds working muscle tissue for up to 7–8 hours, protecting against muscle breakdown while you sleep.

• High-Protein, Low-Fat Formula: Delivers 25g of slow-acting protein per serve with minimal sugar, carbs, and fat to fit strict macronutrient plans.

• Rich in Essential Amino Acids: Naturally packed with BCAAs and glutamine to support comprehensive muscle repair and reduce post-workout soreness.

• Thick & Satisfying Texture: Naturally thicker consistency makes it an ideal evening snack, pudding, or night-cap protein drink.

How It Works

Unlike fast-acting whey isolates that absorb rapidly within the hour, micellar casein possesses unique acid-sensitive properties. When consumed, Rule 1 R1 Casein reacts with stomach acid to form a slow-digesting gel matrix in the digestive tract.

This gradual digestive process slowly releases vital amino acids—including leucine, isoleucine, and valine—into the bloodstream over an extended 7 to 8-hour period. By keeping circulating blood amino acid levels elevated through the night, R1 Casein inhibits muscle protein breakdown (catabolism) and supports ongoing muscle tissue repair while your body rests.

Recommended Use

Mix 1 level scoop (approx. 34g) with 300–350ml of cold water or milk in a Sprint Fit shaker roughly 30 to 60 minutes before going to sleep. Alternatively, mix with less liquid to create a smooth, dessert-style protein pudding for a late-night snack.

Container Size: 907G (2Lb)
Serving Size: 1 Scoop (33g)
Servings Per Container: 28

Container Size: 1.8Kg (4Lb)
Serving Size: 1 Scoop (33g)
Servings Per Container:

We use NZ Couriers as our courier service using an international service. NZ Couriers provides our customers with fast and reliable delivery to destinations across their comprehensive AUS network. 

Standard orders over $60.00 receive free* shipping nationwide, excluding WA, NT, TAS.
Standard delivery starts from $12.90 per shipment for orders under $60.00 
Signature Required $14.90 per shipment. Please ensure you do not have the 'authority to leave' authorization set up at your address with NZ Couriers should you wish to use this service.
If you don't want NZ Couriers to leave your parcel unattended, please select the signature required option. This is especially recommended for high value orders. Neither NZ Couriers nor Sprint Fit are liable for parcels that are stolen, damaged or lost after an item has been delivered.

Final pick up each day is at 3.45pm Monday to Friday. 

*Excludes public holidays and weekends as courier is closed

Click here to view the full Shipping Details and Returns Policy.