Every AlterMe cardio session is a SmartZone session — here's what that means and why it works.
The short version
SmartZone sits in the aerobic training range — challenging but sustainable. You'll sweat, your heart rate will climb, and you'll feel like you worked. You'll also feel like you can go again tomorrow. That's the design.
The science behind it
SmartZone is built around Zone 2 and Zone 3 training — the effort range where your body uses fat as its primary fuel source. Training here builds cardiovascular fitness, increases your muscles' ability to use oxygen efficiently, and improves your body's ability to recover between sessions. Consistently training in this range produces better long-term body composition results than high-intensity work alone — without the damage, inflammation, and burnout that comes with going too hard too often.
How we define your SmartZone
At AlterMe we use the Karvonen method — a formula that factors in both your maximum and resting heart rate to calculate a zone that's personal to you, not just your age. Your SmartZone falls between Zone 2 and Zone 3, giving your sessions room to vary in intensity while staying in the range that works.
What it feels like
Breathing elevated, heart rate up, but in control. If you could hold a short conversation with some effort, you're in it.
Check if you're in it
When wearing your AlterMe Ring and taking cardio sessions or recording an off-screen cardio session, you can see your heart rate change in real time. Purple signals below zone, green signals in zone and red signals that your heart rate is beyond your SmartZone.
The bigger picture
SmartZone cardio is one piece of a system built around your biology. Paired with personalized strength training, recovery sessions, and nutrition guidance tailored to your DNA — it's the combination that drives real, lasting results.