In depth: Fitness goals that matter most (Slideshow)

The Minimum Commitment
Experts say people need to be moderately to vigorously active and develop strength and flexibility. Ideally, you should spend at least 30 minutes a day, five days out of the week on cardiovascular conditioning. Additional time, about 20 minutes, should be allotted for strength-training exercises twice a week. Finally, flexibility exercises can be done in eight to 10 minutes three times a week.

Making the Time
One should strike a balance between planned exercise, like a 5:30 a.m. run, and more improvisational exercise, like taking a mid-afternoon break to do a few coordination or flexibility activities like balancing on one foot or stretching the major muscle groups.

Cardiovascular Speed and Endurance
When improving speed and cardiovascular endurance it's important to use your heart rate as a baseline for goal-setting. A general rule of thumb is to subtract your age from the number 210. Fifty percent of this amount is the maximum heart rate for fat-burning while 70% to 85% of that amount is ideal for cardiovascular fitness. For more casual exercisers, a good gauge of output is working at a pace that allows you to hold a conversation with a little bit of effort.

Building Strength
Developing strength in the upper body, hamstrings, quadriceps, calves and hips is essential for overall fitness. This doesn't always have to be accomplished through weight lifting, but it is an effective approach. Two to three weight-lifting sessions of the proper load can produce a 40% strength gain for a casual exerciser within two to three months.

Coordination
Though it's not a measure of your physical ability, coordination is important in preventing injury and increasing efficiency. These activities include balancing on an unstable surface like a wobble board or doing one-legged squats.

Flexibility
Stretching for just a few minutes a day can help accomplish this goal, as can weekly yoga or Pilates classes. Flexibility exercises offer an added bonus when that quiet time and limited movement is used as a form of stress management.

Preventing Injury
Injuries often happen when weak muscles and tendons strain to complete an eccentric contraction--in other words, when they're lengthening. That's why it's crucial to use proper techniques when strength training.

Recovery
Exercisers should alternate between heavy and light workouts and take a day off after a particularly strenuous day.