The Fitt Principle

Frequency

Frequency refers to how often something is done. For aerobic training, aim for three to six sessions per week, whereas anaerobic training may be prescribed for three times per week.

Intensity

Intensity generally refers to how hard you are working. This can be measured by a percentage of your maximum heart reate, for example, 75 per cent maxHR. It can also be measured by a percentage of your maximum effort. In the gym, this might be 60 per cent 1RM for a bench press or on the track, it may be 85 per cent for your 400-metres run pace. For example, if your personal best for 400 metres is 60 seconds, then you may run intervals at 69 seconds in training. MaxHR can be estimated by subtracting the person’s age from 220.

Time

Time or volume relates to how long or how much and can be measured by time (45-minute run), disntance (20-kilometre bike ride) or number of sets or repetitions (26 sets in the gym).

Type

Type refers to the mode of exercise and may be classified as continuous training or interval training. If you are aiming for aerobic improvements, then the exercise choice should involve large muscle groups such as running, swimming, rowing, walking and cycling.