Nutrition and fitness evaluations abound. But which ones are right for you, and worth your time and money? Find out what some of the top-rated tests can tell you — and what you can do with the results.
Once every six months, Dan Martin, 50, heads to the fitness testing gym at A.T. Still University in Kirksville, Mo., and undergoes a series of tests. Someone pinches the flesh on his abdomen, arms and legs. He jumps as fast as he can from one square on the floor to another to test his agility. He straps on a heart-rate monitor and pedals a stationary bike until he’s hit maximum output. It goes on and on. Test after test.
Sometimes the results are a wake-up call, showing he’s been slacking at the gym and eating too many barbequed ribs. Other times, the results affirm his hard work and motivate him to maintain his fitness and nutrition program. “It’s about being the healthiest 50-year-old guy I can be,” says Martin, director of the university’s Thompson Campus Center and employee fitness program. “Any high school or college competition is half a lifetime ago for me, but this gives me a way to stay in touch with my youth.”
Indeed, regular fitness and nutritional tests provide a yardstick not only to measure your current state of health but also to evaluate how effectively your fitness efforts are moving you forward. The results you see may not only motivate you to exercise more or eat better; they can also help you pinpoint the types of changes that will best help you meet your individual goals.
That said, you don’t have to sign yourself up for every fitness test ever invented. For one thing, there’s only so much information you’re likely to be able to absorb at one time. For another, not every test is necessary – or even useful – for every individual. Below, we profile the tests most commonly recommended by fitness experts to help you evaluate your current state of health, fitness and nutrition, and to make the most effective strides toward improving them.
Body-composition testing measures the ratio of your lean mass (muscles, bones, organs and other metabolically active tissues) to your fat mass. Having an appropriate lean-to-fat ratio is an important indicator of your overall health and fitness, a key factor in healthy aging, and an important consideration in warding off obesity-related diseases like type 2 diabetes and heart disease.
Getting an accurate body-comp measurement is worth doing right. To this end, keep in mind that composition testing and estimating are two very different things. Because muscle weighs more than fat, the tool generally used for estimating body composition – the body mass index (BMI) – can be notoriously inaccurate. Dan Martin is a prime example: At 5-feet, 9-inches tall and 175 pounds, he has a BMI (a ratio of weight and height) of 25, just on the edge of “overweight” according to the BMI tables. Yet, according to a more accurate body-composition test, Dan’s ratio of lean mass to fat is just 11 percent. So he’s by no means fat; on the contrary, he’s very lean – just so muscular that his lean mass weighs down the scale.
The most accurate means of body-composition testing, hydrostatic (underwater) weighing, costs approximately $50. In this test, a technician first weighs you on a typical scale. Next, you sit up to your neck in a water tank. You lean your head forward until you are completely submerged and expel the air from your lungs, holding your breath for 10 to 20 seconds as a machine calculates your underwater weight. Because fat floats and lean mass sinks, your underwater weight, when calculated as a percentage of your on-land weight, offers a very accurate indication of your lean-to-fat-mass ratio.
Unfortunately, underwater testing requires extremely expensive equipment and is generally only available at universities, sports clinics and other specialized settings. Your next best and more convenient alternative? Find a fitness professional trained to test body-composition levels using a caliper, a handheld device used to pinch and measure skinfold thickness at various locations on the body. The fitness professional measures the thickness of these skinfolds then uses several equations to calculate your body composition and estimate your body-fat percentage. Although not as accurate as the underwater test, caliper testing still provides a good gauge at a fraction of the price – most tests cost about $5, but some fitness centers offer it free. (For more on these and other body-composition testing methods, see www.unlv.edu/faculty/golding/bodycomp.html.)
What it can tell you: If you’re fit, your body composition should calculate to somewhere between 14 and 17 percent body fat for a man, and 21 to 24 percent body fat for a woman, according to the American Council on Exercise. Anything over 32 percent for a woman is considered obese; for a man, over 25 percent is obese. Keep in mind that your genetics partially determine your body composition, so focus on improving your health and fitness, not on reaching a magic number.
“Some people are just naturally wired to have 7 percent body fat, whereas others will never get there,” says John O’Kane, MD, associate professor of orthopedics and sports medicine at the University of Washington in Seattle. Still, body-composition testing can indicate whether you are carrying around more weight than is good for you and give you a sense of how much fat you can afford to let go.
There are two types of metabolic tests that benefit folks at virtually any fitness level: resting metabolic rate and VO2 max.
Resting Metabolic Rate. Because oxygen fuels your metabolism, the amount of oxygen you inhale and the amount of carbon dioxide you exhale can reveal your resting metabolic rate: the rate at which your body burns energy (calories) while at rest to maintain a heart beat, brain activity and lung function, among other things.
Until recently, experts typically estimated your resting metabolic rate using a formula based on gender, age, weight and height. But that formula was flawed because it didn’t factor in genetics or body composition. “Some people simply have a slow metabolism and burn roughly 200 fewer calories than we predict,” says Liz Applegate, PhD, director of sports nutrition at the University of California at Davis.
Today, using sophisticated, portable equipment that analyzes your oxygen consumption and carbon dioxide emission, fitness experts can calculate your resting metabolic rate much more accurately. Results vary from person to person, sometimes by as much as 900 calories a day, ranging from a sluggish metabolism of 1,100 calories per day to a fast metabolism of 2,000 calories or more. This test will cost you about $50 to $90.
What it can tell you: The same software that reports your resting metabolic- rate (RMR) results can also determine the number of calories you should eat to gain, lose or maintain your weight, and the number you should burn through exercise to induce weight loss. Taking those results with you when you meet with your registered dietitian for nutritional testing and counseling (see “Nutritional Evaluation,” page 49) can help you develop a carefully tailored eating plan. Knowing your metabolic status may also motivate you to improve it – through exercise, stress management, good nutrition, adequate rest and, potentially, treatment of any metabolic or endocrine disorders that are suppressing your metabolism.
Note that as your weight and level of fitness change, your RMR may drop or rise as a result of your increase in lean body mass, so you’ll want to get retested periodically. There is no set time frame, but a person adding 1 pound of lean body mass per week (which is on the high end) can see enough of a dramatic physiological change after six weeks to warrant being retested.
VO2 max. In addition to relaying information about your resting metabolism, your oxygen consumption is also a key indicator of your aerobic capacity, known in athletic circles as your VO2 max. This is the maximum amount of oxygen (in milliliters) that your body can inhale, deliver through the body and utilize during one minute of exercise per kilogram of body weight.
Your ability to exercise at a high intensity for an extended period of time depends on more than your lung capacity. It also depends on how quickly your heart can pump oxygen throughout your body and how efficiently your muscle cells can use it to create energy. That collection of variables – how much oxygen you can breathe, how quickly your heart can move it through your body and how fast your muscle cells can use it – determines your VO2 max.
During an intense exercise session, your oxygen use increases rapidly at first, and then, as you maximize your exertion, it eventually plateaus at your VO2 max. Although VO2 max is largely genetically determined, with regular intense exercise, even an untrained individual can, over time, raise it as much as 30 percent.
A VO2-max test can also measure your anaerobic threshold (AT). This is the point at which your body ceases burning oxygen in its processing of glucose to produce energy. Exercising below your AT for extended periods of time encourages your body to burn fat. Exercising above your AT is athletically demanding and will cause you to fatigue relatively rapidly, but spending time in this zone can also help you make dramatic fitness gains – gains that make exercise much easier and improve your body’s ability to burn fat even while at rest.
There are generally two types of VO2-max tests: a maximal (or near-maximal “peak”) test, which can be expensive and intense but is also highly accurate; and a less costly, less demanding and somewhat less accurate submaximal test. In a maximal test, EKG monitors are attached to your chest to monitor your heartbeat, and a mask is placed over your mouth and nose to capture expired air. On a treadmill, you begin by walking and then running. (The test can also be conducted on a stationary bike.) Every three minutes, the technician increases the slope and/or the speed of the treadmill. As you near or reach a maximal point of exertion (typically, this takes between 10 and 15 minutes), the technician monitors the rate at which your body is consuming oxygen. Once a maximum or near-maximum level of oxygen consumption is reached, your results are analyzed and reported.
In the submaximal test, your resting heart rate and blood pressure are first determined. Then you cycle (or run) with a heart-rate monitor strapped across your chest for six minutes. You begin cycling at a slow cadence (50 rpm). The technician then gradually increases the resistance on the bike until your heart rate rises to 130 beats per minute. You pedal at that cadence and level of resistance for the remainder of the test. Based on your heart rate during the fifth and sixth minute of the test, the technician can calculate an estimate of your max heart rate and VO2 max. Although it’s not as precise as a maximal test, this assessment delivers helpful information without the physical discomfort and at a fraction of the price – roughly $75 compared to $150 to $200 for a maximal test.
What it can tell you: Your VO2 max can give you a sense of your athletic potential and a benchmark against which you can measure your athletic progress. Your AT is an important indicator of your current fitness. It is also an essential piece of information in accurately determining your most effective fat-burning and cardio-endurance zones.
Optimal VO2-max results vary by age. According to the Cooper Institute for Aerobics Research, for a woman in her 30s, a score above 31 ml/kg/min (maximum amount of oxygen in milliliters per minute) is considered good, above 35 ml/kg/min excellent and above 40 ml/kg/min superior. For a man in his 30s, a score above 41 ml/kg/min is considered good, above 45 ml/kg/min excellent and above 50 ml/kg/min superior.
If you score in the poor range (below 27 ml/kg/min for a woman in her 30s and 35 ml/kg/min for a man in his 30s), you may either be out of shape or have a serious health problem, so consult your doctor before hitting the gym, O’Kane says.
Keep in mind that your VO2 max can shift slowly but usually varies no more than 10 to 15 percent in your lifetime. If you’re just beginning a fitness program, expect your results to improve with every-other-day workouts. If you’re a veteran exerciser, make it your goal to keep your VO2 max from dropping by exercising regularly around your AT.
AT varies from person to person and, for each individual, from sport to sport, but it shifts more readily than V02 max in response to training. Untrained individuals typically have a low AT (approximately 55 percent of VO2 max), while highly trained endurance athletes may have an AT of 80 to 90 percent of their VO2 max.
Through dedicated training, you can raise your body’s AT quite dramatically, so it’s one of the best indicators of fitness status and fitness improvement – and a great athletic goal to work toward. (For more on anaerobic threshold read “The A.T. Factor” in our May 2005 archive at lifetimefitness.com/magazine.)
What you eat affects your weight, energy levels, sleeping habits and, of course, your workouts. So how can you determine whether you are eating the right foods to fuel your healthy lifestyle? Consider a nutritional evaluation. This simple test calls for you to maintain a food log where you write down everything you eat and drink for a week. And that means everything – from the latte and muffin you had for breakfast at the local coffee house to the grilled chicken and salad you made for dinner, and any snacks and treats in between.
You also need to record the estimated portion size (6-ounce yogurt, 1 cup cereal, eight pecan halves, etc.) and include the smallest details, including the types of condiments on your sandwich, the kind of bread you used and even the brand names of prepackaged foods. It takes discipline, but the more detailed your entries, the more accurate your nutritional analysis. You then hand over the log to a registered dietitian who, for between $65 and $200, analyzes your eating habits for calorie, fat, protein, carbohydrate, vitamin, mineral and fiber content and then offers suggestions for dietary improvement.
What it can tell you: Often, we know what we should eat. We’re just asleep at the fork. This test helps you find the motivation you need to dig yourself out of long-entrenched dietary ruts and determine whether you’re consuming too many calories (thus solving the “why can’t I lose weight?” conundrum). It also provides the necessary information to address age-related health problems, such as high blood pressure, high blood cholesterol or high blood sugar.
For example, if you have high blood pressure, you might learn that you’re consuming too much salt and saturated fat. If you have weak bones, you may learn you’re not eating enough foods rich in calcium or vitamin D.
To find a qualified registered dietitian, inquire with your family health professional or with the training desk at your fitness club. You can also visit www.eatright.org, the Web site for the American Dietetic Association, to find registered dietitians who live in your vicinity and specialize in your area of interest or concern, such as heart disease or sports nutrition.
Biomechanics, the study of movement and the forces that affect it, can help you determine how and why you move the way you do and, perhaps most important, how to correct current or potential problems.
An adjustment in gait and body position can eliminate aches and pains and improve your running performance. Correcting your swimming technique can increase your speed and reduce your effort in moving through the water. Emphasizing circular pedal strokes (as opposed to choppy, pistonlike motions) can reduce biking fatigue and improve your tempo. A slight change in your golf stance and body rotation can affect whether you smack the ball down the middle of the fairway or slice it into a sand trap.
Numerous testing labs across the country now offer evaluations that critique your athletic form. (For example, the Boulder Center for Sports Medicine: www.bch.org/sportsmedicine/science.cfm.) Many will also tell you how your bones, muscles, tendons and ligaments are interacting with the forces encountered during your chosen athletic pursuit or sport.
For between $75 and $200, an expert videotapes you as you run, swim, golf or perform some other sport. He or she then analyzes the tape for problems with form, posture and other biomechanical considerations.
Some advanced sports labs take this method one step further, placing reflective markers on key body joints and using high-speed, high-resolution cameras to record your body movements as electronic data. The data is then fed through sophisticated motion-analysis (kinematics) software that analyzes your form.
What it can tell you: If you play a sport, like golf, where proper form directly affects performance, this type of testing can help you pinpoint areas that need improvement. More important, if you suffer from chronic injuries, biomechanical testing can reveal why.
For example, if your feet tend to roll inward as you run, or your bike isn’t properly adjusted to your body, these problems can stress your knees and cause knee or hip pain. The testing can also reveal muscle imbalances that alter your gait.
If you’re interested in getting evaluated, see if your local university has a biomechanics-testing lab or if your fitness club can refer you to a sports clinic or similar resource (like the American Sports Medicine Institute: www.asmi.org/ asmiweb/evaluation.htm).
Once you have results in hand, you may choose to work with a biomechanics specialist, a physical therapist or a sports-medicine physician to correct any problems. These professionals can suggest drills, exercises and even proper footwear to help you overcome habitual postures and musculoskeletal imbalances so that you can naturally improve your form.
Resistance (weight) training is only effective if you use appropriate resistance. To improve muscle strength, you must lift a weight to (or very close to) muscle failure – the point at which you cannot lift the weight even one more time. To pinpoint your proper lifting weight for a variety of exercises, most trainers suggest a one-repetition maximum test.
Although many other similar tests abound, the one-repetition max test is the most common way to estimate your proper workout weight. In this test, you complete a light warm-up set of 10 repetitions. Your trainer then incrementally increases the amount of weight until you can complete only one to two repetitions. From this weight, your trainer can estimate the right workout weight for you.
What it can tell you: Research shows that most fitness enthusiasts lift weights too light to ever reach muscle failure. This type of testing can help you avoid that mistake and maximize your efforts in the weight room by choosing appropriate weights for a resistance training program.
Work with a trainer for a week or two until you get used to the sensation of muscle failure. Be mindful that as your muscle strength increases, you’ll be able to lift more weight, so whenever you reach 10 to 12 repetitions and feel like you could keep going, it’s time to increase the weight. If you find yourself boosting the weights regularly, you might want to retest again with a trainer to re-evaluate your strength-training needs.
Making the Most of Your Results
Anyone dedicated to continually improving his or her health and fitness would do well to consider periodic body-comp, metabolic, biomechanical, nutritional and strength testing. But you don’t necessarily need to do them all – and you certainly don’t need to do them all at once.
Let your personal priorities be your guide. Not sure where to begin? A body-comp test is a terrific benchmark to work against (almost all of us could stand to reduce our fat mass and increase our lean mass). A VO2-max and AT test can tell you exactly how to go about working off any excess chub while significantly improving your fitness results – and avoiding overtraining. A visit with a registered dietitian can help you improve your nutrition, increase your energy and manage your weight. A strength analysis could be just what you need to make your time in the weight room pay off in spades.
Keep in mind, though, that if you happen to test exceptionally well, that’s no excuse to get lazy or throw caution to the wind. And if you happen to test a bit worse than you’d hoped, don’t use it as an excuse to throw in the towel. Make it your mission to use these tests as motivators to improve your health and fitness now, and as markers for maintaining your fitness over time.
“I used to believe that you had to progress, that every time you tested you had to get better,” Dan Martin says. “Now, I believe that if, over five or six years, your scores don’t drop, you are still winning. You’re just as fit as you were five years ago, which means you’ve stalled the aging process.”
Life Time Fitness members: For more information on fitness testing at your club, please contact a personal trainer at the club or through our Web site at lifetimefitness.com/personal_training/contact/.