How long your workouts should last for good health ..................
If your goal is to improve your health, you do not need to do all your exercise
in big chunks. Nowhere is it written — in the U.S. Constitution, the Talmud, or
the California Penal Code — that in order to benefit from aerobic exercise,
you need to do it for 30 consecutive minutes. Studies show that doing three
ten-minute bouts of aerobic exercise has nearly the same health benefits as
doing one half-hour session.How hard you need to push for good health .................................
If you’re simply looking to feel better and improve the quality of your every-
day life, being active is the key, even if you don’t always reach your target
zone (see the “Your target heart-rate zone” section earlier in this chapter).
However, to realize the maximum health benefits — significantly lowering
your heart-disease risk, for example — it’s wise to work out in your target
zone the majority of the time. Plus, even if you have modest goals, you may
want to crank up your intensity just to keep things interesting.Realize that, when you’re a beginner, any exercise you do is high-intensity
exercise. As you get more fit, you need to adapt your routine to match your
increasing strength and lung power. When Liz’s mom started working out, she
couldn’t complete 10 minutes on the treadmill at 2 mph. After three months,
she was able to do 20 minutes at 4 mph — an improvement that in the begin-
ning would have seemed inconceivable.Following a Cardio Plan for Weight Loss ..................................................
If your goal is permanent fat loss, the “cardio plan for good health” isn’t going
to cut it. You simply won’t burn enough calories to make a significant impact.
Here’s why: In order to lose a pound in one week, you need to create a 3,500-
calorie deficit; in other words, you need to burn off 3,500 more calories than
you eat. A 30-minute power walk on flat ground burns about 120 calories.
(See the “Which activities burn the most calories” section later in this chap-
ter.) So, to burn off 1 pound of fat by walking, you’d have to hoof it for more
than 2 hours a day.Chapter 8: Cardio Crash Course 117