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LESSON 1 · Exercise Science 101

Two Different Engines

Cardiovascular exercise trains your heart, lungs, and circulatory system to deliver oxygen more efficiently. Strength training forces muscles to adapt by growing larger and stronger.

Most people default to cardio because it feels intuitive — move more, burn more. But strength training builds muscle that burns calories around the clock, changes body shape, and protects against the muscle loss that accelerates aging after 30.