Earlier quoted context omitted.
How much time do you have to get into shape? When it takes 50 years, the statistic probably doesn't hold because you will be dead by then due to the negative influence of smoking on your health.
It only takes a few months to make substantial gains in c-v fitness.
The first few weeks, at the end of a 10 minute sprint, my heart would be racing and I would be out of breath for 5 minutes after arrival.
I was amazed after 2 months of doing the same thing I wasn't out of breath, it took maybe 1 minute for my heart rate to slow back down.