FLASH SALE // 48 HRS ONLY
Days
Hours
Mins
Secs

Rule 1 Casein Protein Powder

Recover stronger and sleep better with the best casein protein powder in New Zealand, designed to support your muscles while you rest. 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.



Rule 1's mission is to bring you the best formulated and manufactured protein powders and nutrition supplements in the world. To accomplish this mission and remain true to our creed, “the best input = the best output”.

All Casein Protein Powder

Frequently Asked Questions
What is casein protein powder?

Casein protein powder is a slow-digesting dairy-based protein that provides a steady release of amino acids to the muscles over several hours. It’s ideal for use before bed or during long periods without food to support muscle recovery and prevent muscle breakdown.

When should I take casein protein?

The best time to take casein protein is before bedtime, as it fuels your muscles with protein throughout the night while you sleep. It’s also great between meals when you need long-lasting satiety and muscle support.

What’s the difference between casein and whey protein?

Whey protein digests quickly and is ideal for post-workout recovery, while casein digests slowly, making it perfect for overnight recovery. Both are effective, and many people use a combination of the two depending on specific training and nutrition needs.

Can I use casein protein if I’m lactose intolerant?

Some casein protein powders contain low levels of lactose, but not all are suitable for those with lactose intolerance. If you're sensitive to lactose, look for products labelled as lactose-free or choose non-dairy protein powders. We always recommend consulting with your healthcare provider before use.

Is casein protein powder good for building muscle?

Yes, casein protein supports muscle repair and growth by delivering a steady stream of amino acids over time. This helps reduce muscle breakdown and supports lean muscle maintenance, especially during sleep or fasting periods.

Instagram sprintfit

FIND OUT BEFORE ANYONE

Receive exclusive offers and news that will brighten up your day!

Sign up successful!