Later On

A blog written for those whose interests more or less match mine.

“Aerobics” revisited and my current Aerobics score

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I first read Ken Cooper’s book Aerobics when it was published in mass-market paperback format in 1968. I recall working to achieve the amount of exercise he recommended to trigger the “training effect,” in which the body responds by increasing lung capacity, strengthening the heart to pump more blood on demand, expanding the capillary network to deliver more oxygen to muscles, increasing the volume of blood in the body, etc.. As he points out, the training effect requires cardio (aerobic) exercise—exercise that pushes one to consume more oxygen for an extended period of time. He found that an exercise that increases your heart rate to an average of 150 beats per minute and maintains that for 5 minutes, the training effect will begin and will continue as you continue exercising. If the exercise doesn’t raise your pulse rate to that level, then it takes longer for the training effect to begin.

To determine your current level of fitness, you can use Cooper’s 12-minute test. This test is particularly useful if you have been, say, lifting weights and believe that strength implies fitness. You can take the 12-minute test to see how fit you are. The test itself is simply to determine how much distance you can cover in 12 minutes, so it’s best to do it on a track where the measurements are known (one lap being 440 yards). More at the link, including how to interpret test results.

To make it easier to figure out how long you must do an exercise, he assigned point values to different exercises, and he recommended a minimum of 35 points a week for men, 27 points per week for women, attained, for example, by jogging two miles in 20 minutes four times a week or bicycling seven miles in 28 minutes four times a week on a three-speed bicycle. He specifically recommends exercising at least 4 days a week and at most 6 days a week: that ensures that you exercise with adequate frequency and provides at least one rest day a week.

Fortunately, Ken Cooper’s exercise tables are on-line and easily found in a search, and I discovered this entry for walking 4.1 miles (which, according to Plotaroute.com, is the length of my current route).

Since my time is currently around 1:10:00 to 1:15:00, I’m getting 7.2 points of aerobic exercise each day I walk. In reading Cooper’s most recent book, I decided to heed his admonition not to exercise 7 days a week, so I’m cutting back to 6 days a week: 43.2 points per week. (See also this interview with Cooper, in which he advises not overdoing it.)

So I’m getting 8.2 points more than the minimum for men, every week. That’s good, but it gets even better. The 43.2 points per week is a significant underestimate because I am doing Nordic walking, which burns about 20% more calories than regular walking (according to tests done by the Cooper Institute) “without significantly affecting the rate of perceived exertion by the participants.”

Cooper’s points are derived directly from calories burned, and burning 20% more calories doing Nordic walking means that Nordic walking provides 20% more points than regular walking.

20% more than 43.2 points is 1.2 * 43.2 = 51.8 points, and that many points per week is comfortably more than my minimum requirement of 35 points per week (the minimum required to get the benefits of the training effect). And I have indeed noticed evidence of the training effect — for example, the time it takes me to complete the route has steadily dropped.

I think I can safely say that I no longer am sedentary. However, I should point out the health risks of abruptly stopping a walking program.

BTW, the book still reads quite well and the the Cooper Institute is still a going thing. It’s worth looking into. You can get secondhand copies of Cooper’s books cheaply.

And I do highly recommend Nordic walking. My slogan is “Make any repeated task enjoyable!Nordic walking poles made “getting sufficient weekly exercise points” enjoyable.

If you must do some task repeatedly, it’s important to make the task something you enjoy. I had to shave every day, so I figured out a way to make shaving enjoyable (see the Guide). I must eat healthful foods, so I found a way to make healthful foods enjoyable (i.e., tasty). Those food must be prepared right to be tasty, so I found a way to make cooking enjoyable. I must exercise so I looked for a way to make exercise enjoyable. And so on. It you must do some task repeatedly, it’s worth your effort to make doing it enjoyable. If you get pleasure from doing it, you are drawn to doing it.

If you don’t make the task enjoyable, then doing it requires willpower, either active willpower or willpower congealed into habit. In either case, each time you do the task, you decide whether to do it or not, measuring benefit against effort, always with the temptation to skip it “this time.” That problem does not arise if you actively enjoy doing the task.

Update: One occasionally sees a recommendation of 2000 calories of exercise per week. Gretchen Reynolds reports in the NY Times in May 2014:

The idea that we should burn at least 2,000 calories a week during exercise seems to have originated in data gathered decades ago as part of the Harvard Alumni Study. That study followed male Harvard graduates for as long as 50 years, tracking how they lived and died. One of the first publications based on the data, appearing in 1978, showed that the older alumni who expended less than 2,000 calories a week in exercise were at 64 percent higher risk of suffering a heart attack than those who burned 2,000 calories a week or more during exercise. It’s worth noting that the researchers’ definition of exercise in this study was generous, including climbing stairs and walking around the block, as well as playing sports or jogging.

Widely reported at the time, the 2,000-calorie guideline still gets bandied about today. But the current exercise guidelines from the federal government, based on a large body of recent scientific evidence, emphasize time, not calories, and recommend that healthy adults engage in 150 minutes per week of moderate-intensity exercise, such as brisk walking [3mph or faster – LG] or cycling.

Adhering to these guidelines means that most of us would burn about 1,000 calories per week in planned exercise, said Michael J. Joyner, an exercise researcher at the Mayo Clinic. And with the stairs we climb and chores we do, we come closer to that 2,000 calorie a week number, he said.

But we don’t have to fret about actually reaching it. Meeting the current guidelines for 150 minutes or five brisk 30-minute walks per week is enough, he concluded. “The added health benefits start to level off after that.”

My moderate-intensity exercise is Nordic walking, and I do that 390 minutes per week rather than 150. Moreover, a “brisk walk” is 3 mph, and my current speed is 3.8 mph (thus more intensity), and in addition I’m Nordic walking rather than regular walking, and that also increases the intensity. So by this measure as well I’m getting sufficient exercise.

Update 2: The 10,000-steps-per-day goal, as most people probably know, is arbitrary and was created as a marketing idea to get people to buy pedometers (since only with a pedometer can you determine whether you are taking that many steps or not). Knowing that 10,000 steps/day is arbitrary, I ignored it. My initial goal was time, not steps, and I started with 20 minutes a day. As I worked out a good route, that went to 25 minutes and then 30 minutes. Around then I got my Nordic walking poles and started to really enjoy my walk, and also a pedometer app. So I set a daily goal of 5000 steps.

But because I enjoyed walking so much, my walks became longer, and now I walk 66 minutes a day, and I easily meet my new goal of 8000 steps/day. And I find I walk at a cadence of 109-110 steps/minute.

Written by Leisureguy

26 August 2018 at 3:34 pm

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