The term 'WORKOUT EXERCISE' can be summarized by the 6-letter solution 'PUSHUP'. Pushups are a type of exercise that involve pushing up from the ground with the arms and legs, while keeping the back straight. This exercise is used to strengthen the chest, shoulders, and triceps muscles. Pushups are a popular form of exercise for people of all ages and fitness levels, as they can be modified to suit any individual's needs.