Jennifer Ordoñez, a Newsweek journalist who is also a Type 1 diabetic, reported on her experience at a triathlon training camp geared for diabetics. After reading her report, I was curious as to why hypoglycemia would cause a diabetic to fail the VO2 max test.

Nobody likes failing tests - especially when it comes to something as important as VO2 max. VO2 max is the maximum amount of oxygen a person uses while exercising at their limit for one minute. If you are in shape, your muscles will use a lot of oxygen to create energy. The prime source of energy for the body comes from blood sugar. When Jennifer took her VO2 test her blood sugar was falling and she failed. Apparently when blood sugar is falling the body puts itself into energy lockdown which compromises even conditioned athletes VO2 max.

Hypoglycemia causes muscles to fatigue quicker. Muscle fatigue is the result of inadequate oxygen availability. Prevention of hypoglycemia is one of the major objectives of adequate blood sugar when you are about to work out. By maintaining optimal blood sugar, you can assure a better level of exercise performance. I know better than to tell you what to do. But as a friendly reminder: make sure you've fueled up adequately before you hit the gym or the open road to work on your VO2 max.