Complex sentence: The first levels of training such as leaping, tumbling, proper fall techniques, body conditioning form the basis for "taijutsu", these techniques are necessary in order to progress into other techniques such as the use of tools and weapons.
Split into simpler sentences: The first levels of training, such as leaping, tumbling, proper fall techniques and body conditioning, form the basis for "taijutsu". They are needed to progress into other techniques such as the use of tools and weapons.