Cycling rarely happens at one perfectly steady intensity. Hills, attacks, corners, changes in terrain, other riders and race tactics can all force you to repeatedly accelerate, recover and then produce another hard effort.
The 30min Variable Power Cycle is designed around exactly that challenge.
The 30-minute main set constantly changes both the duration and intensity of your effort, ranging from controlled Level I recovery through to very short Level V+++ efforts approaching twice your Functional Threshold Power (FTP). Add a 10-minute Warm-Up and Cool-Down and you’ve got a highly varied 50-minute cycling workout.
It’s particularly relevant to road cyclists and draft-legal triathletes, but mountain bikers, gravel riders and other cyclists who regularly encounter changing demands will also get plenty from this session.
Session Inspiration
The inspiration for this workout comes from research into high-intensity cycle interval training for draft-legal triathletes.
Researchers used variable-intensity cycling as part of their investigation into training methods that could improve cycling and subsequent running performance. The demands of draft-legal racing make this particularly relevant: athletes aren’t simply riding at a constant percentage of FTP—they’re repeatedly responding to changes in pace.
I’ve taken that concept and adapted it into a series of Variable Power workouts of different durations.
You can read more about the research behind the session here:
If you’re ready for the full challenge, you can also find the original 60-minute Variable Power Cycle here:
Today’s Workout
30min Variable Power Cycle (50min Total Time)
Warm-Up
- 10min Level II
Main Set – 3x:
- 60sec Level III (77–83% FTP)
- 10sec Level V+++ (179–194% FTP)
- 70sec Level I (51–56% FTP)
- 40sec Level V++ (141–153% FTP)
- 70sec Level I (51–56% FTP)
- 90sec Level V (109–118% FTP)
- 70sec Level I (51–56% FTP)
- 20sec Level V++ (167–181% FTP)
- 70sec Level II (58–63% FTP)
- 30sec Level V++ (154–167% FTP)
- 70sec Level III (77–83% FTP)
Cool-Down
- 10min Level II
Post-Ride
- 10min Stretching
Total Riding Time: 50 minutes
Why You’re Doing This Session
Most interval workouts are predictable. You ride hard for a set period, recover, then repeat essentially the same thing.
This workout deliberately doesn’t do that.
During each 10-minute block, you’re continually moving between different durations and intensities. One moment you’re riding steadily at Level III, seconds later you’re producing a very short Level V+++ effort, and shortly afterwards you’re recovering at Level I before being asked to go hard again.
That variability challenges your ability to repeatedly produce power, recover quickly and adjust to the next demand.
It’s particularly useful for situations where your power output naturally fluctuates—attacking or responding to an attack, accelerating out of corners, riding over rolling terrain, closing gaps or responding to changes in pace within a bunch.
For triathletes, it can also help develop the ability to tolerate surges on the bike without completely compromising what comes afterwards.
What You Should Focus On
Begin with 10 minutes at Level II. Use the Warm-Up to gradually prepare your legs rather than simply waiting for the main set to begin.
Once the variable work starts, your biggest priority should be matching the purpose of each effort.
The 10-second Level V+++ effort is extremely hard and explosive, but don’t let that intensity carry over into the following recovery. When the workout says Level I, bring the effort right back down.
The longer Level V and Level V++ efforts require a slightly different approach. Get up to intensity quickly, then concentrate on maintaining good technique and consistent power for the prescribed duration.
The Level I and Level II sections aren’t wasted time. They’re what allow you to recover sufficiently to produce another quality effort.
The Level III sections are particularly interesting because they aren’t complete recovery. You’re still riding with purpose while preparing yourself for what comes next.
Common Mistakes To Avoid
Going too hard too soon. With such short, high-intensity efforts, it’s tempting to produce enormous numbers during the first set. Remember that you’ve got three complete 10-minute blocks to ride.
Turning every hard effort into a sprint. Level V, Level V++ and Level V+++ aren’t interchangeable. Respect the prescribed intensity as well as the duration.
Not recovering enough. When you reach Level I, actually ride at Level I. Carrying unnecessary intensity into the recovery periods will reduce the quality of your subsequent efforts.
Switching off mentally. This isn’t a workout where you can settle into one rhythm and forget about it. The demands change frequently, so stay engaged and anticipate what’s coming next.
Chasing the previous set. Your objective isn’t to beat every number you produced during Set One. Aim to reproduce quality efforts across all three sets.
Coach Ray’s Tips
Think of this workout as three 10-minute challenges rather than one long 30-minute interval.
During the first set, learn the rhythm of the workout and resist the temptation to prove how powerful you are during the shortest efforts.
During the second, concentrate on reproducing the quality of the first.
Then, during the third set, your goal is to maintain your technique and power despite the fatigue you’ve accumulated.
Because some of the efforts are extremely short, anticipate each change in intensity. Be ready to increase or decrease your effort rather than reacting several seconds after the interval has already started.
Good cooling is also essential for a workout like this. Use a good fan, have a drink bottle within easy reach and keep yourself as comfortable as possible so that heat doesn’t become the limiting factor.
Most importantly, embrace the variability. The constant changes are the point of the workout.
Coach Ray Rode This Session
I’ve completed this workout myself on Velocity, which allows me to experience the same changes in intensity that I’m asking my athletes to manage.
When reviewing this workout afterwards, I’m less interested in finding one impressive peak power number than I am in looking at the overall pattern.
Can I reproduce the hard efforts across all three sets?
Do my recovery periods actually come back down to the prescribed intensity?
Can I still produce quality Level V++ and Level V+++ efforts during the final 10 minutes?
Those are much more useful questions than simply asking what my highest power output was.
When you complete the workout, have a look at your own data and see how closely your third set resembles your first.
Ride With Me on Velocity
I ride many of these Sunday Smart-Trainer Sessions on Velocity, where you can join me and the Qwik Kiwi Squad for structured indoor cycling sessions.
Rather than simply sitting on an indoor trainer and watching the clock, Velocity gives you an interactive environment in which to complete structured workouts alongside other riders.
If you’d like to experience it for yourself, you can ride FREE for 14 days.
👉 Start your FREE 14-day Velocity trial here:
Give the 30min Variable Power Cycle a go and see whether you can maintain the quality of your efforts as the workout progresses.
The individual efforts might be short, but stringing them together—and doing it three times—is what makes this session such an effective challenge.
If you enjoyed the workout, share it with a cycling or triathlon training partner and check back next Sunday for another Smart-Trainer Session.