Vision Fitness SIMPLE Owner's Manual page 57

TARGET HEART RATE
Target Heart Rate is a percentage of your maximum heart rate. Target
Heart Rate will vary for each individual, depending on age, current level of
conditioning, and personal fitness goals. Exercise heart rate should range
from 55% to 85% of your maximum heart rate. As a point of reference,
we use the predicted maximum heart rate formula of (220 minus age) to
determine your heart rate training zone. Please use the following chart to
determine your predicted Target Heart Rate.
EXAMPLE:
If you are a 30-year-old, your predicted maximum heart rate is 190 based
on the (220 minus age) formula.
Based on the chart above, your heart rate training zone is 104 to 161,
which is 55%–85% of 190.
WARNING
Heart rate monitoring systems may be inaccurate. Over exercise may
result in serous injury or death. If you feel faint stop exercising immediately.
220 – 30 = 190
55