Haas, who turns 35, reached the semi-finals in Florida, beating world number one Novak Djokovic in the round of 16 before eventually going down to David Ferrer in three sets.
The German has suffered with injuries throughout his long career but is now attributing his upturn in fortunes to a combination of mind and body working in perfect harmony.
Much is made of the mental strength required to succeed in tennis but Haas believes his psychological state has been fortified by the knowledge he is putting in the hard yards off the court.
He said: "You look at some of the tri-athletes and iron man guys, they're in their mid-30s and performing at the highest level.
"I think what it comes down to is the older you get the wiser you get.
"Now with nutrition and everything you can do, the right training, the physios that you have, you know, it just helps you mentally, knowing that you're putting in the work.
"You know what works for you best. When you're 21, 22, 23, you're still trying to get into your own body. You might do a lot of lifting, you might do a lot of cardiovascular workout and you try to figure out what helps you the best.
"But with experience - and that's why you see so many 30-year-olds now in the top 100 like never before - and because you're eager, you know this is the way if you want to keep on riding for as long as you can."
Tennis can be a brutally demanding sport physically when you consider the training, matches and travel.
And although world number 14 Haas has no immediate plans to retire, he accepts he has not long left at the highest level.
"It's not golf, you can't play unbelievable (tennis) into your late 30s, 40s, 50s," he added.
"It (a career) is going to be done maybe at 35, 36, 37, depending on when your body doesn't allow you anymore or when you mentally are just drained from all the travelling over the years."
Haas' run to the last four in Miami saw him further appreciate the consistency of the 'big four' - Djokovic, Murray, Roger Federer and Rafael Nadal.
"These kind of weeks ... that's why I respect these guys doing it week in and week out so much," he said.
"It's incredible with all the stuff that comes around with it that I sort of dived into again last week a little bit.
"It's amazing but I think it's great.
"I think it's great that people have the experience in their 30s and are still doing it well."