Part II
When I left off in our April issue, I had just stepped down from the treadmill after my lactate threshold test, then a couple weeks passed and I was back on my way to UIC's Human Performance Lab for a second round of tests: Resting Metabolic Rate (RMR) and VO2 Max.

Not to discount the importance of the previous tests, but VO2 max is regarded as the most accurate assessment of cardiovascular fitness because it measures an individual's maximum capacity to do work aerobically, which is the foundation of endurance sports.

VO2 max is defined as the volume of oxygen your body can consume while exercising at max capacity. So VO2 max is the maximum amount of oxygen, expressed in milliliters, you can use in one minute, per kilogram of bodyweight. In other words, it's your capacity to distribute oxygen to all your hard working muscles during an intense effort, and the larger your capacity, the faster your body can travel over distance.

In terms of measurement, a value of 50 (ml/kg/min) and above is regarded as a high V02 max, with elite athletes registering about 70 or more, and the average sedentary American measuring 35, though figures vary based on age, gender and weight.

Knowing your VO2 max is kind of like knowing your body's potential, and it enables you to see where your vessel stacks up against other athletes, both presently and historically. Some quick research revealed that Steve Prefontaine's VO2 max was 84, Lance Armstrong had 83, and Joan Benoit Samuelson's was 78. The highest score I found belonged to a Swedish cross country skier at 94, and former Tour de France Champ Greg LeMond was an impressive 92.

As for me, I certainly didn't expect to rank with the likes of Lance or Pre, but I hoped to prove that I was more aerobically developed than the average couch potato, or even a tobacco-chewing baseball player.

RESTING METABOLIC RATE
My morning started with the RMR test, which simply measures the amount of calories needed to sustain vital functions of the body during its resting state e.g., how many calories you need just to breath, blink, digest, etc. For this test, the most accurate results occur when you're most relaxed, so I sleepily rolled into the lab at 8 a.m., was escorted by my old acquaintance Amy Jandek to a quiet corner of the lab, and layed down on a table with a towel tucked under my head. I was outfitted with the metabolic analyzer (a rubber mask covering my nose and mouth, connected via air tubes to the high tech data processor vested to my chest), and my job, simply, was to breath. After a peaceful 15 minutes, the end result of the RMR determined that I require a minimum of 1511 calories just to "be." So when you consider that walking, showering, brushing your teeth, etc., accounts for up to 30 percent of your expended calories each day, not to mention running, swimming and/or biking, the standard 2000-calorie diet just doesn't cut it for most athletes.

VO2 MAX TEST
The VO2 max test again found me on a treadmill, this time rigged up with a heart rate monitor, blood pressure pump and the metabolic analyzer. It felt like I was strapped with some pretty heavy artillery, but the equipment has been streamlined over the years and it didn't impede greatly upon my normal running-style, and the rubber mask proved easy to speak and breath through.

This test, like the lactate threshold test, increases in intensity until the subject cannot continue at maximal effort. But unlike lactate threshold test, once I reached a speed of 11 miles per hour Jandek would increase the grade. The idea of this test is to measure oxygen uptake, carbon dioxide production, and total volume while I am working my hardest, and the metabolic analyzer will spit out some numbers that will determine my VO2 max when figured with heart rate, blood pressure and other data.

I started out at level nine (nine mph), and increased one level every three minutes until level 11, then Jandek started cranking up the grade. After 12 minutes and cruising at a speed of 11 mph, the grade was upped to 2.5 percent, and three minutes later, up to five percent, and I decided after 17 minutes I could toil no more. I signaled to Jandek that I had roughly one minute until complete exhaustion. In that final minute, I furrowed my brow and felt my body pleading for more oxygen, and after 18 minutes the test was over.

THE END RESULT
One of the highlights of this whole experience was getting the results back within minutes. No anxious waiting. Jandek crunches some numbers and before my heart rate returns to resting, I am staring at printouts of figures and charts. At first it's all Greek to me, but the fitness coordinators talk me through the results, field questions and make sense of the numbers. On this day, Kim Rostello, the director of the UIC lab, was there to offer her expertise.

As it turns out I have a VO2 max of 64--a little lower than I hoped, but in the general "high" range. Rostello explained to me that you can increase your VO2 max with training, but it's also largely about genetics. My VO2 max is 64, which means I'll never be a 90 or a 30 for that matter, but if I were in peak condition that score might jump up a few points.

This measurement helps explain the wide range of abilities between athletes. Some people are predisposed to being superior athletes, and it's no surprise that Lance Armstrong has a much higher-than-average VO2 max. But of course, various other factors come into play, such as lactate threshold, power, efficiency, mental strength, etc.--each of these being important components to a much larger model that determines whether we're 30-minute 5Kers or Tour-winning cyclists.

The end result of these tests is that I have a better understanding of my physical makeup, but knowledge alone won't make me a better athlete. Looking back at my lactate threshold and VO2 max results, Jandek and Rostello are able to determine the intensity levels (or target heart rates) at which I should train to get optimal results in a complete training program. It is the understanding and execution of such a program that will enable me to discover my athletic potential.

Now I guess it's time to start shopping for a heart rate monitor!

For more information on UIC's Human Performance Lab call 312-413-5266 or visit www.rec.uic.edu and click on Services.

Click here for Part I: UIC Performace lab: Part I - April 2005.