Forget the Scale. Watch These Numbers Instead

Fueled by watching TV shows such as The Biggest Loser, a lot of us are obsessed with what we weigh. (Of course, I should talk, since I've got one of those fancy digital scales from Sports Authority that also measures body-fat percentage.) But while poundage is one indicator of health and fitness, it's a sketchy one at best, because it doesn't take into account bone structure and proportion of lean-muscle mass. And the scale can't tell you what's going on inside your arteries after age 40, or what sort of things you're able to do with your body.

While you don't want to throw out your scale or forget about your body mass index, the comparison of weight to height, here are five other numbers that are just as important to watch.

1. Waist Size.

Waist size is one of the simplest yet most telling indications of a person's health, according to the federal Centers for Disease Control and Prevention. If you're a nonpregnant woman, the CDC says you should have a waist size of less than 35 inches, while men should be less than 40 inches around the middle, regardless of height. Doctors say that people who lose inches off their waistlines almost invariably show improvement in other measures of health, as well.

2. Sodium Intake.

If you're over 40, are African-American or have a history of hypertension in your family, 1,500 milligrams is the maximum amount of sodium that you should be consuming each day. Even if you stop putting salt on your food, it can be tough to get below that limit, because makers of prepared foods often rely on hefty amounts of sodium as a preservative and flavor enhancer. Here's a guide to the DASH dietary program (PDF) for reducing your sodium.

3. Blood Pressure.

Medical experts recommend that your systolic blood pressure, the measure of how hard blood is pressing against your arterial walls, should be 120 or less. But the range between 120 and 140, technically called pre-hypertension, is more like a yellow traffic light than an immediate menace. When you get over 140, however, you're technically suffering from high blood pressure, or hypertension, which can damage your circulatory system and make you more vulnerable to heart disease and strokes. It's simple to keep an eye on this by buying an inexpensive home blood pressure monitor and taking a reading regularly when you first get up in the morning.

4. The Steps You Take.

Those steps should total 10,000-plus a day (and can be measured with a pedometer or an app on your smartphone) to qualify you as an "active" individual, according to a 2004 study by Arizona State University researchers published in the journal Sports Medicine. To be "highly active," you need to take 12,500 steps or more. You can get most or even all of that 10,000 with an hour of brisk walking, but you if you aren't a stroller, you can measure other types of exercise in step-equivalents. An hour of cycling at an easy to medium pace, for example, will also get you over the threshold. About.com offers this chart of the step-equivalents for various activities.

5. How Many Pull-Ups.

If you're a male age 40 or over, you have to be able to do at least three pull-ups to pass the Marine Corps minimum physical fitness requirements. (Here's a video showing the proper technique.) The Marines expect women to be able to do a flexed-arm hang from a pull-up bar for at least 15 seconds. (Here also is a video showing correct flexed-arm hang technique.) Even if you're not in the military, these are pretty good minimum benchmarks for functional upper-body strength. Naturally, if you can do more repetitions or more seconds in the hang, it's a plus.

Keep reading: Making a Fitness Plan for 2012 and 40 (Mostly Free) Ways to Stay Fit