Here's a good VO2max workout I like to do. It doesn't take much time and it won't 'kill' you or make you feel like you want to puke afterwards. I like to start VO2max workouts at the bottom of my VO2max training zone. Each week, I'll move up in that Zone until I'm at the peak of the Zone. Once I'm able to complete the intervals (at the peak), I'll increase my FTP value and train at a higher wattage.
This particular VO2max workout is a 5x4 @ L4/L5 3RI. That means there are 5 four minute intervals at the bottom of the VO2max training zone, with 3 minute rest intervals in-between. I normally have a 10 minute warmup and 5 minute cooldown with all my workouts. I think anything more than that is just a waste of time. Remember, we're all time-crunched. This is a 47 minute workout. That's the other nice thing about it, it's hard and it's quick. Check it out:
What's important when doing these intervals is to make sure that the power level of the first interval is the same as the power interval of the last one. That is, there is no drop in power. If you have to drop your power on the last interval, you're training at too high a power. If you're not feeling tired during the last interval, then you're power is too low. You need to crank it up. The objective of any workout is to be able to complete it (barely) and have no drop in power across all intervals. You can see that my power levels remained consistent (at 220w) across all five intervals. I can tell I was working in my VO2max training zone because my heart rate is usually around the 175 bpm mark- which it was during this workout.
Power ON! Coach Rob