Lee's phenomenal fitness allowed him to perform numerous exceptional physical feats:

Lee's speed in terms of reacting + punching from a distance of three feet away was determined to be around five hundreths of a second (0.05 second); from five feet away it was around eight hundreths of a second (0.08 second).
Lee could take in one arm a 75 lb barbell from a standing position with the barbell held flush against his chest and slowly stick his arms out locking them, holding the barbell there for several seconds.
In a speed demonstration, Lee could snatch a dime off a person's open palm before they could close it, and leave a penny behind.
Lee performed one-hand push-ups using only the thumb and index finger.
Lee performed 50 reps of one-arm chin-ups.
Lee could cause a 300-lb (136.08 kg) bag to fly towards and thump the ceiling with a sidekick.
Lee held an elevated v-sit position for 30 minutes or longer.