Navigating through the world of physical fitness can be overwhelming. You know you should exercise. You've heard about the benefits. But you're not sure of exactly what you should do and how often.

First, it's important to know that research has shown that even short bouts of exercise provide significant health benefits. Yes, making exercise a habit will make a more significant impact on the improvement of your health, but don't let being overwhelmed by fitness principles keep you from exercising. If all else fails, head out for a brisk walk. Any time you spend with your heart elevated reduces your risk of disease.

But, if you're really looking to make exercise a priority and figure out how to schedule it into your daily routine, the first step is understanding how much exercise you really need to do.

A comprehensive workout plan consists of cardio exercise, strength training, and flexibility work.

Cardio Exercise: Boosting the Health of Your Heart

Aerobic exercise increases your cardiovascular health and reduces the risk of heart disease, type II diabetes, high blood pressure, and high cholesterol. It's efficient at burning calories, so it's an ideal type of exercise for maintaining or reaching a healthy body fat percentage.

In order to reduce the risk of heart disease and maintain a stable body weight, the Department of Health and Human Services recommends completing at least 150 minutes a week of moderate aerobic activity or 75 minutes a week of vigorous aerobic activity. You can also combine moderate and vigorous activity and the time should be spread out throughout the week.

Moderate aerobic activity includes exercises like brisk walking or swimming. You should notice an increase in breathing and heart rate and break a sweat, but still be able to comfortably carry on a conversation. Vigorous aerobic activity includes exercises like running and causes a greater increase in heart rate and more rapid breathing. You should still be able to hold a conversation, but in shorter sentences.

If you're just beginning to exercise, any increase in activity is beneficial. It's okay if you're unable to complete long periods of cardio at one time, because it's still beneficial to do multiple brief bouts. For example, if doing a 30-minute brisk walk is challenging, or if you simply don't have a chunk of 30 minutes to exercise, fit in three 10-minute walks instead.

If you're trying to lose weight, you'll need to do more than 150 minutes of moderate aerobic exercise or 75 minutes of vigorous aerobic exercise to burn enough calories to create a caloric deficit.

Strength Training: Building and Maintaining Strength, Muscle Mass and Bone Density

Strength training is a highly beneficial physical activity for everyone. Strength training increases lean body mass, decreases body fat percentage, builds bone density, and boosts resting metabolic rate.

For healthy adults, this translates to more muscle tone, an improvement in physical capabilities, and a reduced risk of obesity-related diseases. For older adults, this means they can limit their natural physical degradation. With age, lean muscle and bone tissue naturally decrease, but regularly participating in strength training limits this tissue reduction and helps older adults maintain healthy physical function and prevents osteoporosis.

As recommended by the Department of Health and Human Services, you should strength train at least twice a week, but three times is ideal. Your muscles need about 48 hours to heal and recover from strength training workouts, so schedule the sessions with one to two days off in between. For example, if you shoot for two workouts per week, a Monday and Thursday schedule is appropriate. For three workouts per week, working out on Mondays, Wednesdays, and Fridays works well.

Flexibility Work: Keeping Nimble

Stretching is an exercise activity that often gets pushed to the side or overlooked, but regular flexibility work is essential for preserving range of motion. Protecting your range of motion is important for maintaining the ability to perform physical activities, including simple daily tasks, such as bending over to pick items up off the floor. If you don't ever stretch, especially with the long hours commonly spent sitting, the hamstrings, glutes, and lower back muscles in particular can become very tight and lead to problems.

The American Heart Association (ASA) recommends that healthy adults incorporate flexibility work into their routines two to three days per week. Stretching sessions should focus on major muscle and tendon groups, such as the hamstrings, glutes, and shoulders. Pilates and yoga incorporate flexibility work into their movements and therefore qualify for stretching.

The ASA recommends that older adults engage in stretching two days per week, with each session lasting approximately 10 minutes. For elderly adults, stretching has been found to improve balance and thereby reduce the risks of falls.

Recap: A Sample Workout Week

Considering all this recommended exercise information, below are two sample weekly workout schedules that meet exercise requirements:

Monday: 30 minutes moderate cardio, Stretching
Tuesday: 30 minutes moderate cardio, Strength training
Wednesday: 30 minutes moderate cardio, Stretching
Thursday: 30 minutes moderate cardio
Friday: 30 minutes moderate cardio, Strength training
Saturday: Stretching
Sunday: Off

Monday: 25 minutes vigorous cardio, Stretching
Tuesday: Strength training
Wednesday: 25 minutes vigorous cardio, Stretching
Thursday: Strength training
Friday: 25 minutes vigorous cardio
Saturday: Strength training
Sunday: Off