I had the opportunity to read a new book by runner Matt Fitzgerald and I will be featuring sections in several upcoming posts sharing his viewpoints and ideas on improving your running. The majority of recreational runners in our society run way too hard and leave their legs tired and never adapt to improve. If you haven’t read his book or do not understand how fitness improves by running easy I suggest you read it. It’s available here at Amazon. And, if you’re one of the many that think you already run easy, you probably aren’t!!

Below is an excerpt from Matt Fitzgerald’s book – 80/20 Running: Run Stronger and Race Faster by Training Slower, where he where he discusses how VO2 max is not a true indicator of running fitness.

From the time it was first identified by Archibald Hill in the 1920s, aerobic capacity was erroneously considered the be-all and end-all of endurance performance. The reason for the mistake had to do with how aerobic capacity was measured. The traditional VO2max test ties together oxygen consumption and fatigue in an artificial way that gives the appearance that aerobic capacity is the one and only factor limiting endurance performance. Modified versions of the test that do away with this problem reveal that a brain-based tolerance for suffering plays as big a role as aerobic capacity does in relation to fatigue resistance. The traditional method of measuring a runner’s VO2max is known as a graded exercise test. In this test, the subject runs on a treadmill while breathing into a mask connected to a machine that collects exhaled gases and uses them to calculate oxygen consumption. The speed of the treadmill is increased by a fixed amount every two minutes until the subject quits in exhaustion. Sometimes a subject’s oxygen consumption increases in lockstep with his or her running speed right up to the point of quitting. Other times oxygen consumption plateaus a step or two before the runner quits. In either case, the design of the test ensures that the highest recorded rate of oxygen consumption falls close to the point of quitting, making it seem as though nothing else besides the ability to consume more oxygen prevents exhaustion. The traditional VO2max test protocol does not resemble how people exercise in the real world. In a race, runners cover a predetermined distance as quickly as possible. This is known as a closed-loop task. By contrast, in a standard VO2max test, runners choose their own finish line by quitting when they feel they cannot continue any longer. That’s an open-loop task.

Consider the example of Paula Radcliffe, one of the greatest female runners of all time. Andrew Jones of Manchester Metropolitan University tracked changes in Radcliffe’s physiology and performance from 1991, when Radcliffe was seventeen years old, until 2003, when she was the best female distance runner in the world. Her highest VO2max was recorded at the very beginning of this period. At that time Radcliffe was running twenty-five to thirty miles per week and her best time for 3000 meters was 9:23. Five years later she was running more than one hundred miles per week and her best 3000-meter time was 8:37, yet her VO2max was no higher (in fact, it was slightly lower). What had changed was Radcliffe’s ability to sustain the speed she’d always had over longer distances. By 2003, she was running as much as 160 miles per week on an eight-day cycle that included fifteen runs, twelve of which (or 80 percent) were done at low intensity. Her VO2max was still unchanged, but in that year, she set a still-standing marathon world record of 2:15:25 and ran a half marathon at an average pace of 5:00 per mile, or 2 seconds per mile faster than the pace she had run for 3000 meters (less than two miles) when her VO2max was at its peak.

Again, this is a direct reprint of the material in Matt Fitzgerald’s book – 80/20 Running: Run Stronger and Race Faster by Training Slower, where he discusses how VO2 max is not a true indicator of running fitness.