Tomorrow insights
Fitness and performance
What happens to your heart during intense exercise (and why recovery matters)
Hard runs, HIIT and Hyrox put real demand on your heart. Here’s what happens to your heart rate and cardiac output, why heart rate recovery matters and how Zone 2 training helps.
Heart health tracking: what your smartwatch is telling you about your heart
Your Apple Watch, Garmin or Oura tracks far more than steps. Here’s what heart rate variability, resting heart rate, heart rate recovery and VO2 max say about your heart health.