Heart disease is on the rise in younger adults. A cardiologist says prevention needs to start sooner.

Incorporating different heart rate zones into a workout can boost fitness and prevent plateaus.

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• A cardiologist said we should think of heart health like retirement savings — start planning early.
• More millennials are facing heart disease, but changing your lifestyle can make a big difference.
• Protect your heart with habits like regular exercise, stress reduction, and increased fiber intake.

You wouldn't wait until your 50s to start saving for retirement ...