Fitness expert Greg Shealey answers common questions about diet and fitness:

Q: How often should I work out?

A: The amount of exercise you need depends on the type of lifestyle you want to maintain. For beginners, most experts recommend at least 20 minutes of exercise three times a week. These 20 minutes can be a combination of four 5-minute sessions of exercise, two 10-minute sessions or 20 continuous minutes. Just doing something is better than no exercise at all. Remember, 20 minutes is considered the minimum prescribed amount of exercise for one day. As your body adjusts to this level of exercise, you should increase the amount of exercise that you are doing to continue receiving the maximum benefits. There are five principle ways you can increase fitness output. These are as follows:

Frequency

Once your routine becomes too easy, increase the number of days that you work out. You can do this by increasing your weekly number of fitness training sessions. For example, if you are pacing yourself correctly, it is OK to increase your exercise sessions from three times a week to four or five times a week.

Duration

Maximize your fitness output. To obtain maximum benefits, increase the length of time that you work out. Gradually try to challenge yourself to extend the period of your workout sessions. For example, if you began your fitness routine walking for 20 minutes a day, after three or four weeks try 25 minutes. Once that becomes too easy try 30 minutes.

Intensity

This means to work harder! To benefit from this principle you must understand your current fitness level. The correct intensity will differ from person to person. For example, if you are used to brisk walking three times a week, try jogging one or two times a week and walking the remainder of the days. Over a period of time, this will increase your aerobic output.

Progression

Progression can mean a variety of different things. You will progress in workouts then you gradually increase the amount of work you do. For example, if you are doing aerobics for 25 minutes, try 30 minutes, or if you lift weights to increase upper body strength, try leg weights to increase your lower body strength.

Overload

Challenging your fitness level is very important.Too little work may have little effect on your body, therefore causing you to waste your time. For each type of exercise, there is a maximum level of force that your body produces. Your current fitness level determines the amount of force you can produce. The overload principle encompasses each of the principles listed. Ultimately, overload means to work harder. Whether you are a beginner or expert, you should always try to work harder than your normal comfort zone. When this occurs, you will be increasing your frequency, duration, intensity and progression.

Note: As always, consult with your health-care provider before beginning any fitness program.