UNM bike test results
I went to the UNM exercise physiology lab in Oct and got a battery of tests done on the bike. The results are below:

power to weight ratio:
This is the results I was most excited and surprised about. This was the highest power to weight ratio I'd ever recorded.
October 2011: 414 watts at 181.2 pounds= 2.28 watts per lb.
July 2010: 428 watts @ 189.1 pounds= 2.25 watts per lb
Jan 2010: 410 watts @ 208 pounds= 1.98 watts per pound

Maximal VO2 (ml/Kg/min):Your VO2 max measured on the cycle was 52.9 ml/kg/min at a maximum power output of 414 Watts. This ranks you in the excellent to superior category (between the 90th and 95th percentile) for your age and gender.

Maximal Heart Rate (beats/min)Maximal heart rate is often used as a tool for setting the exercise intensity by setting a target zone. Your maximal heart rate was measured at 167 beats per minute (bpm). This is the maximal value that your heart can work during cycling, so your regular exercise intensity should not often be at your maximal effort. Your recommended cycling intensity based on your thresholds determined from your test is 83-90% of your max HR max. For you, this would be between 138-150 bpm.

Ventilatory ThresholdYour test results indicated that you have two ventilatory thresholds. The first ventilatory threshold is termed the “aerobic” threshold, and it is the point during exercise where there is an abrupt increase in Ventilation (VE)/Volume of Oxygen Consumption (VO2) without an increase in VE/Volume of Carbon Dioxide Production (VCO2). In other words, you should exercise at an intensity above this threshold to maintain your aerobic fitness. The second threshold is termed the “anaerobic” threshold, and it is the point during exercise where there is an abrupt increase in VE/VO2 and VE/VCO2. In other words, you should exercise above this threshold to improve your aerobic fitness. You should be able to exercise at an intensity between the first and second threshold for an extended period of time. However, you will not be able to exercise for an extended period of time above your second threshold. Therefore, it is best to perform interval training above this threshold. Knowing the ventilatory threshold aids in setting the level of exercise intensity and designing a training plan.Your first ventilatory threshold (the first arrow on the left in the graph below) was achieved at a heart rate of approximately 138 bpm (83% of max HR) and a VO2 of approximately 39 ml/kg/min (74% of VO2max). Your second ventilatory threshold (the second arrow on the right in the graph below) was achieved at a heart rate of approximately 150 bpm (90% of max HR) and a VO2 of approximately 47 ml/kg/min (89% of VO2max).

Since your second threshold was achieved at a heart rate of approximately of 150 bpm, you could potentially exercise for an extended period below this heart rate (though keep in mind that this value can be higher in outside conditions due to heart rate drift and dehydration). A heart rate significantly above 150 bpm will cause you to fatigue at a quicker rate than if you exercised at a lower heart rate.