Actions speak louder than coaches. (Speedo ad)

Here's a good primer on VO2 max, the gold standard of aerobic fitness measurement.

http://home.hia.no/~stephens/vo2max.htm

1) Bike 20 minutes at a warm-up pace.

We are doing three sets of back squats at twenty-one reps each. Choose a weight that you feel you can handle comfortably for twenty-one reps of regular back squats. These specialized movements are tough! Make damned sure you warm-up thoroughly with "air squats" and stretching first.

2) "Power squat":

Lower and rise as quickly as you can while maintaining PERFECT form. Repeat 20 times.

3) "Bottom to bottom":

Lower to full squat position (thighs parallel to floor), hold for a full ten seconds, rise and immediately upon full extension of hip and leg return to bottom and hold for ten seconds. Repeat 20 times.

4) "Super slow":

Take twenty seconds to reach bottom and twenty seconds to reach top again. Repeat 20 times.

5) Finally, how long can you maintain a 2:00 min. 500-meter pace average? Set the rower for "Avg 500 meter pace" and stop and record the time at the instant you fall under the 2:00 minute average (2:00 for men and 2:10 for women).