His golf injuries didn't help. And for what it's worth his life choices are not that different than a pile of golfers before him. Golf has never been famous for producing a bunch of choir boys.

Tiger’s body structure and genetics were a gift early in his career; then became a curse.
His mother was small boned and wiry; built for speed and flexibility. His dad was a large boned, big bison of a man.
As Tiger got older, his dad’s muscular genetics were starting to take over and Tiger’s relatively little bones couldn’t support the stress.

In addition; when his dad’s passed, he had an overly determined, unreasonable, ill advised desire to attain extreme conditioning and mass through Navy Seal like training…..that is something the human body does well 20yo to about 32yo. Once you get passed 32yo or so, those sort of quick multidirectional jumping and lifting exercises like Navy Seal training and P90X etc will destroy your knees and spine.

Yes, pro golfers throughout the history of the PGA tour have practiced putting on the 19th green across the nation from tour stop to tour stop.

Jack is the greatest pressure putter the game has ever seen. He and Tiger both are great pressure shot makers. Lets not forget the game when Jack came into it. Arnie had it headed the right direction and Jack help that and also kept it going. I also feel like, as already mentioned, the competition Jack faced every year was much tougher. Tiger came along when the game was lagging and it needed a hero. Fit, flatbelly Tiger started against a bunch of fat guys wearing polyester stretchy coaching pants.

Yup Lee Trevino was in great shape