Certainly the "lung capacity and fitness of an 18 year old" that's the headline feature is a VO2Max score which is extremely variable, responsive to training an

Certainly the "lung capacity and fitness of an 18 year old" that's the headline feature is a VO2Max score which is extremely variable, responsive to training and doesn't decline that steeply. Looking at his posted "18 year old" score in comparison with reference charts, it's a bit above average for someone in their mid twenties (who probably doesn't work out much), well into the "very good" range for someone about to turn 40, and yes it's excellent for someone who's 47... but it's an upper percentile score for someone in an upper percentile of fitness obsession, not a miraculous teenage body.