Spending forever on a treadmill or doing any aerobic exercise is futile without goals. If you're frustrated with your training and have been unable to reach your fitness or weight loss goals, ensure you follow a cardio plan that gets you results quickly and effectively.

A 45 year old should perform aerobic exercise for at least 150 minutes per week at a moderate intensity, or 75 minutes if it's seriously intense, says the Centers for Disease Control and Prevention.

Make Me Healthy

A lack of time is a major reason you may not be hitting the road or taking an aerobics class, especially when business and family duties are tight on your heels. While most major organization suggest healthy adults to do about 150 minutes of moderate-intensity physical activity weekly, you can reduce your risk of cardiovascular disease and premature death by fulfilling half of the recommendation.

If time is tight, help your health along by raising your heart rate three times a week for 25 minutes. Whatever form of activity you choose — jogging, vigorous landscaping or circuit training — be sure to get your heart pumping. Make these short sessions intense, so it's hard to sing a song or talk in sentences longer than three words.

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To lose fat, you must drop the excuse of not having time to exercise. It’s a big goal to lose weight, and a bigger challenge to keep the weight off. You need more than 250 minutes of moderate-intensity activity every week to lose one to two pounds per week, according to the American College of Sports Medicine 2.

Reduce your risk of injury by varying the type of exercise you do during the week. A combination of group exercise classes, outdoor hiking and elliptical routines throughout the week can be effective. But consider adding a circuit training class that utilizes aerobic and resistance training intervals. As long as your heart rate remains elevated, it counts toward your weekly accumulation of aerobic activity, burning fat and toning your muscles.

Go the Distance

Aerobic capacity is the ability of your heart, lungs and blood vessels to meet the oxygen and energy needs of your muscles. If you have been sedentary for the last six months, are unable to walk a mile or if you want to finish a group fitness class, you must increase the endurance component of your aerobic capacity. The intensity of your exercise has to be low enough so you can go for a longer duration.

When you first start out, you may feel winded after 10 to 15 minutes. You can perform two or three of these short sessions per day and still meet your weekly exercise goal, or gradually add time to each session to eventually exercise 30 minutes on most days. Depending on your current fitness level, you may add as little as two minutes to your daily walk or as much as 10 minutes to your jog.

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Age is a risk factor for cardiovascular, pulmonary and metabolic disease. If you're a 45-year-old man, make an appointment to see your doctor prior to beginning a focused exercise program. If you're a 45-year-old woman and you or your immediate family members have a cardiovascular, pulmonary or metabolic condition, you should also see your doctor. While exercise is beneficial for adults with no signs, symptoms or risk factors of disease and illness, unsupervised exercise could be dangerous if you have an existing medical condition.