The letters stand for Frequency, Intensity, Time, and Type; and all are in reference to the exercises within your program.
The FITT Principle puts your workouts into an acceptable range that works against injuries. Knowing the frequency, intensity, time, and type that fits into your lifestyle and fitness experience level will keep you from doing too much, overtraining, and getting negative consequences from your efforts.
At some point you may experience plateau as a result from same workout routine. So here are the solution!
Change your FREQUENCY. Frequency helps you adjust the times your exercise throughout the week by considering how often you can attend a class, get to the gym, or do an at-home or outdoor workout.
Choose your INTENSITY. The intensity of a workout or exercise is a gauge of how hard you work. Are you feeling the burn or just enjoying a light sweat? Are you lifting heavy or swimming in a pool? In other words, is your workout low, medium, or high intensity?
Make sure right amount of TIME spend. The relationship works like this: if you can have a higher frequency, you can workout for shorter periods. If you have low intensity workouts throughout 6 days, you can workout for longer periods every single day. Similarly, if you 3-days high intensity at 30-45 minutes in length, the other two days in your program might contain swimming and yoga classes, which could span 2-3 hours.
Your goals determine the TYPE of exercise. Those who are focusing on improving cardiovascular fitness will use exercises like swimming, walking, hiking, stair climbing, jogging and running. Those who want muscular gains will do strength training and bodyweight calisthenics, like pull-ups, push-ups, squats, leg presses, and kettlebell exercises. Athletes who are cross training might add in skill-related drills, like agility and balance or focus on pairing training in their specialty alongside an opposing activity.
Stay Safe. Stay Healthy.