Strain

Measure the impact
of every step
and rep.

i bio's cardiovascular strain score quantifies every physical effort on a 0–21 scale. Know when you're building fitness — and when you're risking injury by overdoing it.

Today's Strain

12.4

out of 21

Calories

1,847

RecoveryLightModerateHeavyAll Out

Heart Rate Zones

Know your zones.
Train smarter.

i bio calculates your personal HR zones based on your maximum heart rate and lactate threshold — not generic formulas. Every zone is calibrated to your physiology.

Recovery< 115 bpm

Active recovery. Promotes healing.

Aerobic115–138 bpm

Fat burning. Foundation for endurance.

Threshold138–155 bpm

Pushing your lactate threshold.

Anaerobic155–172 bpm

High-intensity. Builds power.

Max> 172 bpm

All-out effort. Short bursts only.

Today's Zone Breakdown

22%

35%

20%

15%

Measure the impactof every stepand rep.

Know your zones.Train smarter.

Train with purpose.Not just effort.

Measure the impact
of every step
and rep.

Know your zones.
Train smarter.

Train with purpose.
Not just effort.