VO2max is considered the best indicator of your cardiovascular and cardiorespiratory fitness. Train smarter.

This smart T shirt:

Sensor: 3 pioneering soft flexible leads, more precisely
Heart Rate, HRV (allowing to estimate stress and fatigue), Heart Rate Recovery, and ECG
Breathing Rate, steps counted,calories burned
Activity intensity, peak acceleration, steps, cadence and sleep positions
Bluetooth connectivity with iPhone, iPad and Android
Safe for any kind of activity, Can be used to monitor pretty much any type of activity: running, cycling, sleeping, just plain living!
Quick dry, breathable, lightweight.