FAQ ~ Var in Session Descriptor
Why do some sessions have "var" in them?
Not all of our sessions are ridden at a quasi "steady-state" pace.
For instance, for the FTP Development sessions, you get up to a speed, power, heart rate, perception of whichever marker you choose, then ride at that pace for the duration.
We can do this because we know (when we have an accurate FTP figure) exactly what level of intensity can be sustained, and for how long, on our endurance intervals.
With long intervals, there is a perfect correlation between intensity and time. That's because they have a mainly aerobic element to them, which we can control and predict.
However! For shorter intervals, or varying load intervals, this "predictability line" becomes blurred due to the many physiological variables and individual idiosyncrasies with which we are all blessed.
These differences mostly involve anaerobic capacity, heart rate range, lung capacity, the "base fitness" of the athlete, their motivation, heat, hydration and many, many other things over which we have no control.
For this reason, we can only put "var" as variable prescriptor for these sessions.
You can see the Escalating Block session above, increases the load as time passes. One could easily pedal at 100 rpm in the first minute, but I doubt anyone could for the last!
Not all sessions can be prescriptive, and neither should they be, We are all different, and as long as we've done our best that's all we can ask of ourselves.