Tiger's Extreme Workouts Risked His KneeDuring four days of special-ops training in Fort Bragg, N.C., "Tiger did two tandem parachute jumps, engaged in hand-to-hand combat exercises, went on four-mile runs wearing combat boots, and did drills in a wind tunnel. Tiger loved it, but his physical therapist, Keith Kleven, went a little crazy worrying about the further damage Tiger might be doing to his left knee...One morning I was in the kitchen when he came back from a long run around Isleworth, and I noticed he was wearing Army boots. Tiger admitted that he'd worn the heavy shoes before on the same route. 'I beat my best time,' he said."