When you next need to exercise perhaps a gadget can help motivate you? Christine Junge, an editor at Harvard Health Publications, tried three different types and reports back.
Pedometers
A pedometer keeps track of the number of steps the wearer takes. Many models also calculate how many calories you’ve burned. It’s the least expensive device I tested and the easiest one to use.
The Omron HJ-112 Digital Premium pedometer, which sells for about US$20 on Amazon.com, was recommended by a colleague. It’s about the size of a small mobile phone and clips to your waistband or belt.
You input your weight and the average length of your stride to keep track of the steps you’ve taken, miles you’ve walked, and the calories you’ve burned. You get your stride length by taking a few steps, measuring how far you went, and dividing that length by the number of steps you took.
A meta-analysis published in The Journal of the American Medical Association in 2007 concluded pedometers do, in fact, motivate people to walk more – some 2,000 extra steps a day, or about a mile.
But having a goal – a common one is walking 10,000 steps a day – is essential. The meta-analysis found that pedometer users who set their sights on a step total of some kind (not necessarily 10,000) became more physically active, but users without a goal did not.
I already walk a fair amount – 30 minutes of fast walking is part of my daily commute. I didn’t have a goal, so just as the research would predict, my daily step total didn’t increase during my testing period. But I can see how watching your pedometer numbers could motivate you to walk more.
Heart rate monitors
A heart rate monitor has a sensor that measures how fast your heart is beating. A stretchy strap goes around your torso and holds it against your chest. The sensor sends a signal to a wristwatch-like gizmo that displays your heart rate and, based on the age, gender, and weight you’ve inputted, translates that rate into the calories you’ve burned.
You can use a heart rate monitor to see if you’re getting a good aerobic workout. A commonly used formula for figuring out your target heart rate is to first get your maximum heart rate by subtracting your age from 220 and then to multiply that number by 0.5 to get the low end of the range and 0.85 to get the high end.
At a cost of about US$110, the Polar F6 heart rate monitor is one of the cheaper models. It’s comfortable and doesn’t show under your clothing. I work out on an elliptical machine, and I liked using the monitor to see if my heart rate was in the “good” aerobic workout range. I pushed myself harder than I would have without the monitor.
Activity monitors
Activity monitors are technologically sophisticated. The brand that Harvard tested, the Bodybugg, calculates the calories you’re burning by measuring motion, the amount of heat you’re giving off, and, indirectly, how much sweat you’re producing.
But at US$350, it’s expensive. It’s also conspicuous. I found the Bodybugg, also marketed as SenseWear, impossible to wear under shirtsleeves unless they were very loose. A man stopped me on the street to ask me about the device. He was nice enough, but it was still embarrassing.
It was fun, though, to see my burn rate: 0.9 calories per minute as I slept, 1.3 as I tapped away on my computer, and 6.1 as I trotted to catch my train. Bodybugg claims its product is 90% accurate.
Like the heart rate monitor, there’s a wristwatch-like component that displays how many calories you’re burning from moment to moment. You can also upload data from the device to the Bodybugg website (www.bodybugg.com).
The website has a nifty feature that allows you to enter your food intake and then see charts that compare how many calories you’ve consumed with how many you’ve burned.
Access to the site comes at a price though – US$15 per month after a free 3-month trial.
The bottom line
The inexpensive pedometer probably makes the most sense if your main form of exercise is walking or running. If you want to keep tabs on your aerobic fitness, or if you bike or do some other form of exercise that a pedometer couldn’t track, then a heart rate monitor might be better.
The Bodybugg has the “fun factor” going for it – always a plus when it comes to exercise – and the number crunching and charts generated by the website will appeal to those who like to see progress recorded.
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