Being physically fit means that your body has the attributes to function efficiently and effectively. These attributes necessary for being fit can be broken into five separate components, including cardiovascular endurance, muscular strength, muscular endurance, flexibility, and body fat composition. A comprehensive workout regimen should include aspects to target and improve each of these five components.

1. Cardiovascular Endurance

Cardiovascular endurance is the ability of your cardiovascular system, including your heart, lungs and circulatory system, to efficiently work at a higher intensity over an extended period of time. Your lungs are able to bring in more oxygen, which is then delivered to your heart to pump through the circulatory system to your working muscles.

Aerobic exercise activities are ideal for developing cardiovascular endurance. Examples or aerobic activities include jogging, biking, walking, climbing stairs, or cycling on an elliptical machine. The American Heart Association recommends performing at least 150 minutes per week of moderate aerobic activity, or 75 minutes per week of vigorous aerobic activity to improve cardiovascular endurance. Ideally, the aerobic activity is split into separate sessions throughout the week. For example, five days doing 30 minutes of moderate aerobic activity for a total of 150 minutes for the week.

2. Muscular Strength

Muscular strength is the amount of force that your muscles are able to produce in a single effort. Building and maintaining strength allows you to lift, carry and move heavier items. Lean muscle tissue, and therefore strength, naturally decreases as we get older, so it's important for people of all ages to make an effort to develop and maintain strength.

To build muscular strength, regularly participate in a weight-training regimen. A comprehensive workout should target all the major muscle groups, including the chest, back, shoulders, arms, hips, legs and core. A good workout for beginners is chest press, back row, shoulder press, leg press, leg curl, leg extension, calf raise and abdominal curl. Lift weights two to three days per week with at least a day off in between each workout. Do two to three sets of four to 12 reps.

3. Muscular Endurance

Muscular endurance is the ability of your muscles to perform repeated contractions or hold a single contraction over a period of time without fatigue. Having muscle endurance allows you to perform many daily activities, such as putting away grocers, playing with kids at the park and doing yard work, with greater ease.

Both aerobic exercise and strength training build muscular endurance. To focus on developing endurance during your strength-training workout, use slightly lighter weights than you would for building strength and complete two sets of 15 to 25 reps of each exercise.

4. Flexibility

Flexibility is the ability of your body's muscles, ligaments, tendons and joints to move through their full range of motion without tightness or discomfort. Being flexible directly affects your ability to perform daily tasks, such as bending over to pick up something off the floor. Maintaining proper range of motion and preventing tightness also reduces the risk of injury and contributes to the health of your lower back.

The best way to improve flexibility is to participate in a stretching regimen every single day. Static stretches, which involve getting into a position to elongate a muscle and then holding that position for 20 to 30 seconds, are the most effective for developing flexibility. A basic stretching routine includes standing quad stretch, split-leg calf stretch, lying hamstring stretch, hip flexor stretch, iliotibial band (ITB) stretch, lying knee-to-chest stretch, and shoulder stretch.

5. Body Fat Composition

Body fat composition is the amount of fat you're carrying on your body. A healthy body composition is one that has a high ratio of lean tissue to fat tissue. Men should have a body fat composition lower than 17 percent and women should have a body fat composition of lower than 24 percent. Being at a healthy body fat percentage reduces your risk of overweight-related health issues, such as heart disease, type II diabetes, high blood pressure, and arthritis.

To improve your body fat composition, burn a higher number of calories than you consume. You can increase the number of calories you burn with frequent cardiovascular exercise. Strength training also helps, because the lean muscle you build subsequently boosts your metabolic rate and makes you burn more calories throughout the day. To reduce the number of calories you consume, follow a healthy eating regimen of primarily fruits, vegetables, lean proteins and whole grains and reduce your intake of high-calorie, low-nutrient foods and drinks.