During spring and summer, my exercise routine changes quite a bit, and yard work is my workout at least a few days a week.
In the spring, grass grows fast, and to stay on top of my lawn I have to cut it frequently, more than once a week.
My lawn takes about 1 1/2 hours to cut, not including trimming or weeding.
How does a bout of yard work stack up against a prolonged treadmill walk?
When you compare the cost of treadmill walking with manipulating a big power mower (even one that is self-propelled), the caloric cost of mowing can be 10 percent to 20 percent more than walking briskly on the level.
I walk uphill on my treadmill, which increases the caloric cost, and therefore, my mowing and treadmill work probably cost nearly the same on a per minute basis.
Since I work longer in my yard, however, the overall cost of my yard work will be substantially more.
When I'm not cutting grass, I'm hauling mulch, digging or doing other gardening chores.
Although I keep myself in good shape throughout the year with a faithful exercise program, I still get sore and achy from yard work.
This is because I use different muscles, or I use the same muscles but in a different way.
Thus, hauling mulch can make my biceps sore even though I regularly perform dumbbell curls.
This is called "task specificity" — muscles get in a groove when performing a particular exercise in a particular way.
But if you move outside that groove, even just a little bit, it's a new and different exercise as far as your muscles are concerned.
But since you don't see it that way, you tend to push the muscles hard in this new direction, and — bingo — they get sore.
Exercise routines
Several days a week, I walk on the treadmill in my home. I may do this first thing in the morning, or, if that doesn't work, I do it when I can.
Some days, I feel like pushing myself a bit, other days I don't. I always start with a slow walk for several minutes to allow my joints to warm up and get ready for more vigorous work.
I gradually increase my walking speed from 2.5 mph to about 4.2. I also play around with the elevation, raising it to 8 percent to 15 percent, depending on how I feel.
The amount of time I walk can vary, depending on circumstances and how I feel, from as little as 10 minutes to nearly an hour.
As you can see, I am flexible when it comes to my exercise, because I refuse to get locked into the kind of compulsive and regimented approach I employed years ago.
While I walk I enjoy listening to the radio.
I quit jogging quite a while ago because of the residual effects on my knees and lower back.
Any jogging aggravates old injuries, and for days afterward my knees hurt when I climb stairs, and my back is stiff in the mornings.
For years, after giving up jogging long distances, I switched to long walks outdoors and jogged only when I encountered hills, because I would use a type of shuffle that didn't bother my knees as much.
But eventually that became bothersome too, so it's all walking for me now.
Resistance training
Approximately every five days, I go to a gym for some resistance (weight) training.
For a little more than an hour I perform a wide variety of exercises with light dumbbells and on the many machines.
I fell in love with weight training when I was about 13 years old, and I still look forward to it.
Unfortunately, I have to be careful about what exercises I do and how I do them, because lots of old joint injuries lurk if I get too frisky or careless.
I conclude my weight-training session with a bout on an elliptical trainer for 10 to 15 minutes.
On days when I cannot exercise, I do something that has helped me manage my weight over the years. (At 6 feet 2 inches, I weigh 200 pounds — exactly what I weighed in high school.) I've been doing it so long, I do it automatically now.
I cut back on what I eat that day, plus I eat more fruit — an extra apple or grapefruit, for example, instead of something that has more calories.
Bryant Stamford is an exercise physiologist and director of the Health Promotion and Wellness Center at the University of Louisville. If you have questions about sports injuries, health, exercise or fitness, write to Body Shop, Gannett News Service, care of The Courier-Journal, 525 W. Broadway, P.O. Box 740031, Louisville, Ky. 40201-7431, or e-mail bryant@louisville.edu.