Monday, September 17, 2007

Target Heart Rate Training for Effective Aerobic Workouts

(This is a selection from some of the articles found on my website)

Cardiovascular training is one of the key components of an effective workout program. Whether you are training to lose weight, add muscle, increase definition, or simply to improve your heart and lung function, aerobic routines are a necessity. The key is to determine how often, at what level, and of what duration (the familiar formula of FIT-frequency, intensity and time). An examination of each of these factors will provide guidelines for setting up your own personal program.

FREQUENCY
This will be determined by your current fitness level, exercise history, and goals. Someone who wants to lose a significant amount of weight will need to perform cardiovascular exercise 3-5 times per week. The bodybuilder looking to increase definition will probably be aiming for 2-3 times per week, in order to maximize fat loss while retaining muscle. The key is to gauge results each week, and adjust the program accordingly. The weight loss candidate who has a goal of losing 2 pounds a week , but finds himself falling short of that goal, will need to look at adding an additional session or two. The bodybuilder trying to achieve greater muscle definition may have to cut out a session if he finds he is losing muscle size.

INTENSITY
The American College of Sports Medicine recommends exercising at an intensity of 60%-90% of maximum heart rate, or 50%-85% of heart rate reserve (Karvonen Formula). What exactly does this mean? Each method has a formula to determine your proper range.

Target Heart Rate is determined by multiplying your maximum attainable heart rate by the upper and lower ranges:
(220-Age) x 60%= Lower Limit
(220-Age)x90%=Upper Limit

For example, a 35 year old would have a target heart rate range of 111-167 beats per minute. The 220 figure in the formula is a standard based on the assumption of the maximum heart rate of a baby, and each year this rate decreases by one beat.

Target Heart Rate using the Karvonen Method (Heart Rate Reserve)
This formula is a little more involved, as it takes into account your resting heart rate. Resting heart rate is best measured first thing in the morning, before you get out of bed. Take your pulse by pressing your index and middle finger at the wrist (on the thumb side of your hand) or at the carotid artery on the neck. Take a 10 second count, then multiply by 6 to get a 60 second count. This is your resting heart rate. It's best to do this 3 days in a row, then average the readings to get an accurate resting heart rate.

For the following example, let's assume your resting heart rate is 60bpm (beats per minute), and your age is 35:
RHR (Resting Heart Rate)=60
MHR (Maximum Heart Rate)=220- your age=220-35=185
HRR (Heart Rate Reserve)=MHR-RHR=185-60=125

Now you can calculate your training heart rate:

(HRRx50%) + RHR = Lower end of range
(125x50%) + 60= 123

(HRRx85%) + RHR = Upper end of range
(125x85%) + 60 = 166

This method would yield a range of 123-166 beats per minute.

The Karvonen Formula is considered the more accurate measure of heart rate, but the first formula is the most simple to use. What exactly is the purpose of the training ranges? In order to get an effective workout, it's necessary to get your heart rate up to at least the lower end of the range (aerobic threshold), where there is enough stress to produce improved cardiovascular strength. The upper end of the range is the maximum limit at which you want to stress the cardiovascular system-beyond this range produces no further beneficial effect, and can be taxing on the heart.

TIME
An aerobic workout has 3 parts: the warm-up, length of time in target heart range, and cool down. The warm-up is done to increase core temperature, and warm up muscles and connective tissue. This will decrease the chance of muscle and heart strain, and should last from 5 to 10 minutes. During this time, heart rate should be gradually raised until you reach your target training range. This is followed by at least 20-30minutes in your range, ending with a 5-10 minute cool down. The cool down is the most important of all, gradually lowering your heart rate to avoid straining the heart and prevent blood pooling. Blood pooling is a condition where the blood that your heart has been pumping out to the extremeties hasn't had enough time to return to the heart, which could result in fainting or a possible coronary incident.

So what's the best length of time for you? Longer sessions are necessary when exercising at a lower intensity, to make the most of fat and calorie burning. This is a safe structure for seniors and beginning exercisers. More advanced participants should aim for a higher intensity and shorter duration, to maximize fat burning and minimize muscle loss.

THE MYTH OF THE FAT BURNING ZONE
Unfortunately, this myth still persists and is evident in many health clubs. Pass by any cardio area and you'll see lines of people working out a a very low intensity for long periods of time. Inevitably, these same people will wonder why they're not losing weight or body fat, even though they're training in the "fat burning zone." Yes, it's true that your body will burn a higher percentage of calories from body fat when exercising at a lower intensity during aerobic activity. But, at a higher intensity, you'll burn more calories. Although a smaller percentage of calories will come from body fat, it's a smaller percentage of a larger number. Which means that you'll actually burn a larger number of calories from body fat! Step up the intensity of your cardio exercise, and you'll find you can shorten the workouts and achieve greater results.

RPE
Target heart rate ranges are not always the most accurate measure of training intensity. Certain medications (especially those for blood pressure, such as beta-blockers) can produce an artificially low heart rate. In this case, one should follow the guidelines of their doctor regarding heart rate. The Borg Scale, or Rating of Perceived Exertion (RPE), is an alternate or complementary method of measuring exercise intensity. Based on a numbered system from 6-20, it estimates intensity from very, very light at the lower end of the scale to very, very hard at the upper end. The Revised Scale estimates effort and runs from 1-10, with 1 being nothing at all, a 5 is strong, and 10 is very, very strong. This can aid an exerciser in gauging how hard they are working, and avoid overexerting.

USING A HEART RATE MONITOR
I recommend that every one of my clients conduct their cardiovascular training using a heart rate monitor. A monitor provides a continuous readout of your heart rate, eliminating the need for trying to take a pulse during exercise. This constant feedback allows you to adjust the intensity every minute if necessary, which would be a challenge with pulse taking. The readout is more accurate than hand sensors on cardio equipment, as the strap is worn next to the skin, directly under the chest. It's convenient for outdoor exercising, such as jogging ,bike riding, etc. Otherwise, there's no way to measure the effectiveness of these activities with much precision.

GET MOVING
Cardiovascular exercise requirements vary by individual, but are necessary for progress in any training regimen. The improvement in heart and lung function will complement your efforts in strength and flexibility training, as well as endurance activities. Like strength training, the workouts must be structured to ensure continual progress and avoid plateaus. Many times clients ask me if a certain exercise is a good cardiovascular workout. Anything that gets your heart rate up in your training range and maintains it for at least 20-30 minutes qualifies. So pick your poison-Stairmaster, anyone?

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