Bone mineral density governs your ability to run, lift, and absorb impact for the next three decades. Most people will never measure it until something breaks. Learn why your T-score may be the most important number you don't know — and how a DEXA scan changes the prescription.

VO₂ Max is the strongest predictor of your future health — better than cholesterol, weight, or blood pressure. Learn what it means and how to improve it.