Feint
Sports Dictionary
Bruce Lee: "Among other things, don't try to cheat yourself in any exercise: work only with the weight you will handle without undue strain."
A threatening deceptive movement of the arm or torso made by an athlete in order to provoke an opponent to anticipated defensive or attacking techniques. A feint is used to hit an opponent in the open part of the opponent's body-head or upper body. Deceptive feints can be used both on offense and defense.
Related to boxing terms
Other definitions in the section "Boxing terms"
Bruce Lee: "Among other things, don't try to cheat yourself in any exercise: work only with the weight you will handle without undue strain."