SUNRISE
HEARTBEAT CHRONICLES

If you have ever finished a workout and glanced at your smartwatch, you have probably noticed those coloured heart rate zones flashing across the screen. Zone 2 for the long walk. Zone 4 for the treadmill sprint. Zone 5 when the last hill absolutely destroys you. But have you ever wondered what any of it really means for your heart? For many Singaporeans keeping active through park runs at East Coast, morning laps at the neighbourhood pool, or weekend hikes in Bukit Timah, he