After his match with Wong Jack Man in 1965, Lee changed his approach toward martial arts training.
Lee felt that many martial artists of his time did not spend enough time on physical conditioning.
Lee included all elements of total fitness muscular strength, muscular endurance, cardiovascular endurance, and flexibility.
He tried traditional bodybuilding techniques to build bulky muscles or mass.
However, Lee was careful to admonish that mental and spiritual preparation was fundamental to the success of physical training in martial arts skills. In Tao of Jeet Kune Do, he wrote
Training is one of the most neglected phases of athletics.
Too much time is given to the development of skill and too little to the development of the individual for participation. ... JKD, ultimately is not a matter of petty techniques but of highly developed spirituality and physique.
The weight training program that Lee used during a stay in Hong Kong in 1965 placed heavy emphasis on his arms.
At that time he could perform single bicep curls at a weight of 70 to 80 lb (about 32 to 36 kg) for three sets of eight repetitions, along with other forms of exercises, such as squats, push-ups, reverse curls, concentration curls, French presses, and both wrist curls and reverse wrist curls.
The repetitions he performed were 6 to 12 reps (at the time).
While this method of training targeted his fast and slow twitch muscles, it later resulted in weight gain or muscle mass, placing Lee a little over 160 lb (about 72 kg).
Lee was documented as having well over 2,500 books in his own personal library, and eventually concluded that "A stronger muscle, is a bigger muscle", a conclusion he later disputed.
Bruce forever experimented with his training routines to maximise his physical abilities, and push the human body to its limits.
He employed many different routines and exercises including skipping rope, which served his training and bodybuilding purposes effectively.
Lee believed that the abdominal muscles were one of the most important muscle groups for a martial artist, since virtually every movement requires some degree of abdominal work.
Mito Uyehara recalled that "Bruce always felt that if your stomach was not developed, then you had no business doing any hard sparring".
According to Linda Lee Cadwell, even when not training, Lee would frequently perform sit ups and other abdominal exercises in domestic living throughout the day, such as during watching TV. She said of Lee, "Bruce was a fanatic about ab training.
He was always doing sit-ups, crunches, Roman chair movements, leg raises and V-ups".
Lee trained from 7 am to 9 am, including stomach, flexibility, and running, and from 11 am to 12 pm he would weight train and cycle.
A typical exercise for Lee would be to run a distance of two to six miles in 15 to 45 minutes, in which he would vary speed in 3–5 minute intervals.
Lee would ride the equivalent of 10 miles (about 16 kilometres) in 45 minutes on a stationary bike.
Lee would sometimes exercise with the jump rope and put in 800 jumps after cycling.
Lee would also do exercises to toughen the skin on his fists, including thrusting his hands into buckets of harsh rocks and gravel.
He would do over 500 repetitions of this on a given day.
An article of the S. China Post writes "When a doctor warned him not to inflict too much violence on his body, Bruce dismissed his words. 'the human brain can subjugate anything, even real pain' — Bruce Lee ".
