This is a short video of several clients at the studio performing Intervals called "Zoomies". Zoomies are 8-second intervals, with just 6 second recoveries. We performed FORTY of these in 3 sets.
The goal is to ride the 8 second intervals at a relatively high intensity, maybe 150-200% of Threshold. Then the cyclist spins through a short recovery. I used it on Tuesday, and multiple cyclists achieved breakthroughs on Xert. I'm using it today as well, to similar effect.
These also make for GREAT simulations for Crit or Cyclo-Cross bike races. In those events, athletes are forced into short, sharp, hard intervals, with minimal recovery.
Ironically, we were supposed to perform 13 minute and 8 minute Critical Power intervals to try and determine Critical Power and Anaerobic Work Capacity today. However, these "Zoomies" have led to multiple fitness breakthroughs for average power on PerfPro Analyzer.

One of my clients, James, is using a Moxy Muscle Oxygen Monitor, and our goal for him is a bit different. We are trying to get his SmO2% down into the single digits, which is REALLY HARD. At the same time, I am watching his Total Hemoglobin, which hovered in the low 12's for about 45 minutes. It now is down at 11.95.
Why? Well, he's running out of blood and muscle sugar, and a carbohydrate drink might be appropriate right now. I'll post screenshots in a bit.
What's also interesting is showing how quickly (or not), his SmO2% rises after an interval set. If it gets back up into the mid to high 80's for him, that's when it may be an optimal time to ingest more carbohydrates, OR drink a recovery drink.
If you want to get fit for cyclo-cross season, or maybe just enjoy some overall strength in your fitness, give these a try. You can also perform these intervals outdoors, racing from telephone or light pole to the next pole, and then recovering. Repeat to exhaustion, or until you run out of space!