Sunday, April 25, 2010

Exercise, Part II: Getting Started

Perhaps you, like many patients I talk to, would like to begin an exercise program, but the idea seems overwhelming. It can be if you decide to start a program without a sound plan, because it will almost certainly not be something you can sustain for the long run. Patients often have no idea how long to exercise, how much to stress or strain their system, or how long it takes to "get in shape". All of this tends to lead to early errors, injury, or discouragement and giving up on the idea of becoming fit. It is important, and possible, to avoid this trap with the proper approach.

If you haven't been exercising regularly, it is important that you first consult with your doctor about whether it is safe. If you are 45 years of age or older, it is probably a good idea for you to obtain a treadmill exercise stress test. It is also important to have a good idea of your risk factors for cardiac disease, including your cholesterol and blood pressure level. You should also get a reading of your body mass index and set a target for your weight (more on weight loss later).

Assuming you get the green light, I recommend starting with about 15 or 20 minute sessions, three days a week. You should choose an aerobic activity, such as walking, jogging, biking, swimming, or an exercise machine like a treadmill or an elliptical machine. Aerobic activities are important to form the basis of your program because they are sustainable and lead to better cardiovascular fitness. We'll talk about the value of anaerobic activities, especially weight workouts, later.

If possible, either work out on a machine that has a heart rate monitor or else purchase a wireless continuous heart rate monitor. It is very difficult to exercise for fitness efficiently without one and they have become very affordable in recent years. As I noted earlier, it is important to exercise in the "aerobic" zone, which is about 60 to 80% of your maximum heart rate. You can obtain an estimate of your maximum heart rate by subracting your age from 220. For example, if you are 30, your estimated maximum heart rate is 220-30=190. So your exercise target is between 114 and 152. I usually recommend a midrange target of 70% or about 130 for this example.

It is important to be patient and persistent, remembering that each day builds on the last and that rest and exercise work together to stregthen the muscles and the cardiovascular system. By starting at 20 to 30 minutes three days a week, you minimize the risk of becoming too sore or fatigued to continue your program. A good rule of thumb is to increase your workouts by about 10% per week. So, if you start with 30 minutes, three times a week the first week, then you should increase one of your workouts by 10 minutes the second week. Then, the next week, increase one of your other workouts by 10 minutes. The next week, increase one of your workouts to 45 minutes and repeat the cycle. When you are up to 45 minutes three times a week, then add a 15 or 20 minute session on another day a week; then increase that session to 45 minutes, until you get to 5 days a week, 45 minutes a session. By the time you have reached this schedule, you will have completed at least 12 or 14 weeks and should have achieved a pretty good level of cardiovascular fitness. Congratulations!

Then, when you have achieved this schedule, which is reasonable to maintain, you can continue to pursue your fitness by maintaining your heart rate targets as you become more fit. As you do this, you will actually work harder and the the "10% rule" will continue more or less automatically by allowing you to "do more work" at the same heart rate as you become more fit. This is called the "training effect".

Next time, we'll talk about issues with motivation and what to do when you "fall off the wagon".

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