Precor 904 175, 165, 160, 155, 148, 144 140, 132 135 128, 124, 120 116, 112, 108, 114, 107

Diagram 15

Training zones

		HEART RATE TRAINING ZONE
		190	185
	190			180
					175
	180					170
							165
	170							160
	160								155
		152								150
RATE			148								145
	150			144
					140							140
HEART	140					136	132						135
								128
YOUR	130								124					MAX.
										120
											116			HEART
	120	124	120									112		RATE
				117									108
	110				114	110
							107							80% OF
	100							104
									101	98				MAX.
											94			HEART
	90											91	88	RATE
														65% OF
	80													MAX.
														HEART
	70	20	25	30	35	40	45	50	55	60	65	70	75	RATE
						YOUR AGE

How Hard Should I Exercise?

Studies show that to achieve the benefits of aerobic exercise, it is necessary to work out hard enough to raise your heart rate to a certain minimum level, called the “training zone.” Your training zone depends on your age and level of fitness.

Diagram 15 shows your recommended heart rate training zone which is calculated using your age and your maximum attainable heart rate. The chart is based on a resting heart rate of about 72 for males and 80 for females. Your optimum training zone is between 65% and 80% of your maximum heart rate. For efficient aerobic exercise, work only hard enough to keep your heart rate in this zone. You will obtain the greatest fat-burning benefits when you exercise within the optimum training zone.

Pushing yourself beyond the recommended range, (that is, exercising so hard that your heart rate rises above 80% of maximum) can overstress your muscles. To increase cardiovascular improvement, exercise longer, not harder.

Keep in mind that this zone is an approximation, to be used as a guideline— individual heart rates vary according to several physiological factors. To determine your training zone, find your age on the diagram, and then find the line where they intersect. For example, if you are 35 years old, your training zone is between 114 and 140 beats per minute. Remember this zone—this is the heart rate zone you should try to maintain as you work out.

If you do not have an accurate heart rate monitor, you can determine your heart rate by taking your pulse at a place that you can reach easily and comfortably while you exercise. Typical locations for measuring heart rate are directly over the heart on the left side of the chest, on either side of the neck, over the temple, or on the thumb side of either wrist. Wherever you measure your pulse, make sure that you use your index and middle fingers—not your thumb. Your thumb has a strong pulse which can affect your heart rate reading.

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