Gray hair, age 60: "you guys are always so extra. How about sailing? A brisk sea breeze always refreshes."

NAD 51.2 umol/L, age 16: "Gray_hair, honestly, get it together and rejuvenate yourself. You’re making us all look bad."

Lungs FEV1 age 22: "That’s a great idea. I’m in. Hey Max Heart_Rate_183_age_37 can you step up your game today? We nearly had the boys beat until you tapped out the last 500 meters."

VO2Max 53.6 mL/(kg·min), age 18: "We did 3.27 miles in 33 min, climbing 1,000 ft. You averaged 159 bpm. A cool 170 bpm average would have done it. I have the capacity."

Diaphragm 155/117 cmH2O inspiratory/expiratory, age 20: "Me too"

45 years have passed since I exited my mother’s womb. During the past 18 months, I’ve endeavored to measure - and then biologically age match - my every organ and biological process.

One can be chronologically aged 45, but have a heart biologically representative of a 32 yr old, or 71. On my bday, I imagined my body deciding what to do for the day:

Heart Rate Variability (HRV) 54, age 40: "Let’s go race the mountain trail again!"

@Chad_Hurley or ÷?

@santiagoroel truth may also be a form of validation