Should You Splurge on an VO2 Max Test?

Gretchen Ashton, owner of ScubaFit (which recently got PADI to create a training course for dive and fitness instructors to teach fitness to divers) recently wrote an article titled "Scuba Fitness: Oxygen Utilization Testing for Scuba Divers." ( www.examiner.com/topic/advanced-scuba-diving/articles ). She writes that by knowing your oxygen utilization (VO2), a measure of cardiovascular and metabolic efficiency, you might improve your aerobic capacity, and presumably also improve your gas consumption both on the surface and underwater.

V02 max is the maximum amount of oxygen one can utilize during intense exercise, and is expressed in milliliters of oxygen used in one minute per kilogram of body weight. The individual mounts a treadmill or bicycle, is fitted with an alien-looking head rig of tubing that allows for measurement of the volume and gas concentrations of inhaled and expired air, and then workload is gradually increased. By the end of the exercise, the person will be giving his all, and I mean all.

To suggest that a routine recreational diver expose himself to this rigor strikes me as somewhat excessive. VO2 max typically is of interest only to serious endurance athletes, and recreational diving under usual conditions would be considered only a moderately intense activity at best. Moreover, one does not find a human-performance testing facility on every street corner. And if you do find one, you can expect to pay around $175 or more to get your VO2 max measured.

Also, while such direct testing certainly is the most accurate measure of V02 max, it also can be reasonably estimated by exercise stress testing such as the Bruce protocol. For the average diver, it might be easier to obtain it this way, especially if you're over age 45 and getting a periodic routine stress test as part of your wellness physical (which you should be). Even simple heart rate can provide a rough estimate of O2 transport and predict aerobic fitness.

I contacted Ashton to verify the VO2 values indicated, and the claim that such assessment might benefit the typical diver. Her response was as follows, "I'm very busy with other projects, and not planning on writing more about this topic at this time. I am also concerned about how you plan to represent me since we have no history of collaborating on articles."

Well then, unless you're in training to be a "marathon" diver, don't waste your money.

- - Doc Vikingo