Derny › Workouts › Adaptive Threshold
Adaptive Threshold · threshold training
Three 8-minute threshold blocks, held by heart rate. Your warm-up shows Derny how your heart responds, and each block starts from what the last one taught it. No FTP test. On a smart trainer, a treadmill or an elliptical.
New to threshold training?
Your threshold is the hardest effort you can hold before fatigue starts stacking up. Below it, you can keep going for a long time. Above it, fatigue builds quickly and you have to slow down within minutes. On the usual five-zone scale it sits around zone 4: hard, steady breathing, a few words at a time.
Easy sessions build your base. Threshold sessions use that base to improve performance: they raise the pace or power you can hold before fatigue takes over, which is what decides most races and long climbs.
Regular threshold work lifts the effort you can hold for long stretches, on the bike or on the run.
A short, focused session that does a lot of work for the time it takes.
Threshold is uncomfortable but steady. Done right, you finish tired and could have done a little more.
Most of your training stays easy. One or two threshold sessions a week sit on top of it. See zone 2 training.
The hard part
Set the power or pace from an old test and the blocks are too hard on a tired day and too easy on a good one. Go too hard in the first block and the last one falls apart. Heart rate lags behind effort, so chasing it by hand overshoots.
Adaptive Threshold handles that for you. It watches how your heart responds in the warm-up, holds you around your target through each block, and opens the next block from what the last one showed. Your last Threshold session sets where the next one starts.
Your target
Derny suggests a target at 78% of your heart-rate reserve, the gap between your resting and max heart rate. For a max of 185 and resting heart rate of 48, that’s 155 bpm. On a heart-rate-reserve scale that’s the top of zone 3, just under threshold: a range some coaches call “sweet spot”.
If you know your threshold heart rate, from a test, a coach or your watch, set the target to it, or nudge it up or down at any point during the session. You can set it as high as 6 beats under 95% of your max.
What the session looks like
You start easy and Derny steps it up until your heart rate nears your target, then holds. The first block opens at your last Threshold session’s work setting, or where this warm-up ends on your first one.
The power or speed brings your heart rate up, then Derny keeps adjusting it to hold you around your target.
Enough time to catch your breath, but not enough to lose the effect of stacking your effort.
Derny starts each block from what the one before taught it, with another 4-minute recovery between them.
On your machine
On any FTMS smart trainer in ERG mode. Trainer compatibility →
Derny counts down, sets the belt to an easy speed and steps it up from there, never above your max auto speed. In the recoveries the belt drops back to the easy speed your warm-up started at. Treadmills →
On an elliptical that takes a power target, Derny sets the watts. On others, it shows the target and you set the resistance. Ellipticals →
What you need
Questions people ask
Threshold training is riding or running at the hardest effort you can hold before fatigue starts stacking up, usually in blocks of several minutes. It raises the pace or power you can sustain.
It varies from person to person. On five-zone scales it’s around zone 4, often quoted as roughly 80–90% of heart-rate reserve or 85–90% of max heart rate. A test, a coach or your watch can give you a personal number.
Yes: three 8-minute blocks held around a target heart rate, with recoveries between them. Derny’s suggested target sits just under threshold, at 78% of your heart-rate reserve. If you know your threshold heart rate, set the target to it.
Sweet spot is an effort a little below threshold: hard, but easier to recover from. Derny’s suggested Threshold target sits in that range, and you can raise it to train at threshold itself.
No. Adaptive Threshold is set by heart rate. Your warm-up shows Derny how your heart responds, and each later session starts from where your last one worked.
Yes. On a treadmill that takes speed commands, Derny sets the belt speed for each block from your heart rate, never above the max auto speed you choose.
Most plans keep the bulk of training easy and add one or two harder sessions a week. Do Adaptive Threshold on a day you’re rested.
Try it
When Derny launches, it will be a one-time purchase, not a subscription.
Want to go harder? See VO2 max intervals with Adaptive MAX Out.