N4x4

N4x4 - Norwegian 4x4 HIIT Trainer

Ready to transform your fitness? N4x4 brings you the scientifically-backed Norwegian 4x4 HIIT protocol—the most efficient way to boost your VO2 Max and build a bulletproof cardiovascular system.

WHY N4x4?

• It's set and forget: Press start, then just train. No fiddling with timers.
• Visual and audio cues guide you through every interval
• Perfect for beginners and advanced athletes alike

WHAT YOU GET:

• 5-minute warm-up to prepare your body
• 4 rounds of 4-minute high-intensity intervals
• 3-minute recovery periods between rounds
• Real-time heart rate zone display based on your age

WHY VO2 MAX MATTERS:
Your VO2 Max is the single greatest predictor of lifespan. Studies confirm high-intensity interval training like Norwegian 4x4 is the most efficient way to improve it. Top longevity experts (like Dr. Peter Attia) swear by it.

NO STRINGS ATTACHED:

• 100% free
• No sign-ups
• No ads
• No in-app purchases
• Just you and your workout

Download N4x4 now and start building a stronger, healthier heart today. Your future self will thank you.