The term intenisty in fitness is part of the F.I.T.T. principle. FITT stands for frequency, intensity, time, and type of exercise. Intenisty denotes how hard you work during exercise and it is correlated with the breathing and heart rate. According this definition, the statement that increased intensity refers to how greatly one increases the level of training is false. How greatly one increases the level of training denotes the progression principle in fitness.
