What training principle is being observed when the body becomes stronger and function better when demands of exercise are increased?

The FIIT principle is a straightforward guideline for revising and improving any workout plan. FIIT stands for frequency, intensity, time, and type of exercise. You need to think about these four elements to create workouts that fit your goals and fitness level. 

For instance, working out 3 to 5 days a week with a mixture of low, medium, and high-intensity exercise for 30 to 60 minutes per session, and performing cardio and strength training. Working out these details and progressing them over time helps create an effective program.

The first thing to set up with your workout plan is frequency—how often you will exercise. Frequency often depends on various factors, including the type of workout you're doing, how hard you're working, your fitness level, and your exercise goals.

In general, the exercise guidelines set out by the American College of Sports Medicine give you a place to start when figuring out how often to work out for both cardio and strength training.

Cardio workouts are usually scheduled more often. Depending on your goal, guidelines recommend moderate cardio exercise five or more days a week or intense cardio three days a week to improve your health.

If you want to lose weight, you may want to work up to more frequent workouts, up to six or more days a week. Just remember that more is not always better, and recovery time is essential.

The recommended frequency for strength training is two to three non-consecutive days a week. You should have at least one to two days between sessions.

Your frequency, however, will often depend on the type of training sessions you perform as well as your goals. You want to work each muscle group at least two times a week if your goal is to build bigger muscles, for example. If you do a split routine, like upper body one day and lower body the next, your workouts can be more frequent than total body workouts.

Intensity has to do with how hard you work during exercise. How you increase or decrease intensity depends on the type of workout you're doing.

For cardio, you will usually monitor workout intensity by heart rate, perceived exertion, the talk test, a heart rate monitor, or a combination of those measures.

The general recommendation is to work at a moderate intensity for steady-state workouts. Interval training is done at a higher intensity for a shorter period. It's a good idea to have a mixture of low, medium, and high-intensity cardio exercises, so you stimulate different energy systems and avoid overtraining.

Monitoring the intensity of strength training involves a different set of parameters. Your intensity comprises the amount of weight you lift, and the number of reps and sets you do. The intensity can change based on your goals.

• If you are a beginner looking to build muscle, stability, and endurance, use a lighter weight and do fewer sets with high repetitions: two or three sets of 12 to 20 reps.
• If your goal is to grow muscle, do more sets with a moderate amount of repetitions (for instance, four sets of 10 to 12 reps each). You can build muscle with a wide range of repetitions and weights, but volume (total number of repetitions), is often higher than for other goals.
• If you want to build strength, use heavy weights to do more sets with fewer reps (five sets of three reps each, for example).

The next element of your workout plan is how long you exercise during each session. There isn't one set rule for how long you should exercise, and it will typically depend on your fitness level and the type of workout you're doing.

The exercise guidelines suggest 30 to 60 minutes of cardio, but the duration of your workout will depend on your fitness level and what type of exercise you're doing.

If you're a beginner, you might start with a 15- to 20-minute workout. If you have some experience and are doing steady-state cardio, such as going for a run or using a cardio machine, you might exercise for 30 to 60 minutes. If you're doing interval training and working at very high intensity, your workout will be shorter, around 10 to 15 minutes for all-out effort-based interval training.

Having a variety of workouts of different intensities and durations will give you a solid, balanced cardio program.

How long you lift weights will also depend on the type of workout you're doing and your schedule. For example, a total body workout could take over an hour, whereas a split routine could take less time because you're working fewer muscle groups in one session.

The type of exercise you do is the last part of the FIIT principle. It is easy to manipulate to avoid overuse injuries or weight loss plateaus.

Cardio is easy to change since any activity that gets your heart rate up counts. Running, walking, cycling, dancing, swimming, and the elliptical trainer are some of the wide variety of activities you can choose. Having more than one go-to cardio activity is the best way to reduce boredom and increase variability.

Strength training workouts can also offer variety. They include any exercise where you're using some type of resistance (bands, dumbbells, machines, etc.) to work your muscles. Bodyweight exercises can also be considered a form of strength training.

You can easily change the strength workouts you do, from total body training to adding things like supersets or pyramid training, to liven things up. Incorporating new exercises for each body part is another way to vary the type of workouts you do.

You may wish to spend a few weeks working on functional strength-based movements, then move to hypertrophy or strength-based programming. Each of these modalities includes various alternative types of strength-based exercises to try.

The FIIT principle outlines how to manipulate your program to get in shape and get better results. It also helps you figure out how to change your workouts to avoid boredom, overuse injuries, and weight loss plateaus.

For example, walking three times a week for 30 minutes at a moderate pace might be a great place for a beginner to start out with a workout program. After a few weeks, however, your body adapts to these workouts. As a result:

• You burn fewer calories. The more you work out, the easier it is to do the exercises because your body becomes more efficient.
• Weight loss stalls. Your new workouts may lead to weight loss, but when you weigh less, you expend fewer calories moving your now-smaller body.
• Boredom sets in. Doing the same workout for weeks or months on end can get old, eating into your motivation to exercise.

It's at this point you want to manipulate one or more of the FIIT principles. For example, you might:

• Change frequency by adding another day of walking
• Change intensity by walking faster or adding some hills or running intervals
• Change time by walking for a longer time each workout day
• Change the type of workout by swapping one or more of your walks for swimming or cycling

Even just changing one of these elements can make a big difference in your workout and in how your body responds to exercise. It's important to change things up on a regular basis to keep your body healthy and your mind engaged.

The FIIT principle is a well-established way of modifying and adapting exercise programming to fit your unique goals, lifestyle, preferences, and progress. You can change and adapt each of the factors to suit these needs. Incorporating changes to frequency, intensity, time, and type of exercise helps to stave off boredom while also providing a framework for continued progress.

Frequently Asked Questions

• Which are the main components of fitness?

  The main components of fitness are cardiovascular training, resistance training, and mobility, stretching, and recovery work. Each are important for a healthy, functional body and lifestyle.

• Is a 1-hour workout enough to achieve your fitness goals?

  If you have one hour per workout day to train, this is usually plenty, depending on what your goals are and how many days per week you are training.

  One-hour workouts three to four times per week with a mixture of cardiovascular and strength training can be effective, depending on your effort, workout structure, and other aspects of your lifestyle. Even 10 minutes of exercise each day can make a huge difference to your health.

• How do you use the FIIT principle if you are a beginner?

  Using the FIIT principle if you are a beginner to exercise does not have to be complicated. Simply review each of the four aspects and decide on what to start with. For example, how many days of the week can you commit to? What type of exercise do you want to try? After a month or so, you can revisit the FIIT guidelines and choose one or two to modify.