David Siik’s Treadmill Ladder Balances Speed, Incline and Recovery

The central idea behind David Siik’s treadmill ladder is simple: as the incline rises, the speed falls. That tradeoff lets runners add climbing work without stacking speed and grade until the session becomes too taxing to finish or recover from. For treadmill workouts, where every variable can be set precisely, the structure also gives each interval a clear purpose.

Siik, founder of Precision Run by Equinox and author of The Ultimate Treadmill Workout, describes the method as a way to coordinate speed, grade and duration. “It prescribes the right speeds on the right inclines, for the right amount of time so that you are able to maximize your performance while minimizing impact on your body,” he says. The logic is practical: a harder setting in one dimension calls for restraint in another.

Set your treadmill pace first

The workout uses a personal reference point Siik calls your “one-minute PR”: the treadmill speed you can sustain for a one-minute hard effort. The working intervals should be about 2 miles per hour slower than that speed. If your one-minute PR is 7 mph, for example, begin the run intervals at 5 mph. That target should feel like a 9 out of 10 effort, with 10 representing an all-out effort.

Use the effort scale as a check, not just the treadmill display. Siik’s suggested pace should feel hard but repeatable; you should have the sense that you could complete a few more intervals without the final incline if the workout required it. If the first repetition feels maximal, the chosen speed is too aggressive for the session.

If you don’t know your one-minute PR, Siik offers a rough way to estimate it by testing 5 mph:

• If 5 mph feels easy enough to maintain without breaking a sweat, your one-minute PR may fall between 8 and 10 mph.
• If 5 mph is faster than a comfortable easy run, your one-minute PR may be between 7 and 9 mph.
• If 5 mph feels like interval pace, your one-minute PR may be around 6 mph.
• If 5 mph feels like a near-exhausting sprint, your one-minute PR may be closer to 4 or 5 mph.

These ranges are estimates rather than precise measurements. Use how the pace feels to guide the starting setting, then adjust as needed to keep the effort controlled.

The ladder workout

The sequence alternates one-minute running intervals with one-minute walks. Each time the incline increases by one percentage point, reduce the speed by 0.2 mph. Start with the pace established above.

1. Warm up with 5 minutes of light jogging at RPE 2.
2. Run for 1 minute at 0% incline at RPE 9.
3. Walk for 1 minute.
4. Run for 1 minute at 1% incline, reducing speed by 0.2 mph from the opening interval. Aim for RPE 9.
5. Walk for 1 minute.
6. Repeat the run and walk pattern for five more repetitions. Raise the incline by 1 percentage point each time and lower speed by another 0.2 mph each time.
7. Cool down with 5 minutes of light jogging at RPE 2.

The result is a progressive climb through the workout, with speed stepping down as the grade rises. The walk breaks provide recovery between hard efforts. The structure lets runners increase the workload in measured increments instead of making speed and incline climb together.

Adjust effort before the workout gets away from you

Outdoor pace won’t always give you a reliable treadmill setting. Running in place can change how a pace feels, and runners accustomed to GPS watches or marathon pace may find the treadmill rhythm unfamiliar. That’s why Siik’s one-minute PR and perceived exertion are more useful starting points than simply copying an outdoor split.

Siik also recommends beginning below the target effort and building. A 9 out of 10 interval from the first repetition can leave little room for the later, steeper efforts. Starting around 6 out of 10 for the first few intervals gives you time to settle into the treadmill pace and preserve energy for the rest of the ladder.

That adjustment matters for runners still learning how to manage speed changes, too. The schedule may call for hard efforts, but the first run doesn’t have to prove anything. Raise the effort gradually as you understand how the belt speed and incline combine for your body.

Scale the session for different goals

Siik says this format can fit into training throughout the year, including as a replacement for a weekly interval session. For runners preparing for longer distances such as a marathon, he suggests reducing the run interval speed by 1 mph and setting the walking breaks at a pace about 2 mph slower than the run pace.

He calls this adjustment “cushioning.” The workout still alternates work and recovery, but the difference between the two efforts becomes less pronounced. That can make the session more manageable when the aim is to retain interval training without pushing the hard efforts as sharply.

The method can also suit newer runners because recovery is built into the pattern. Siik says these workouts often run 30 to 45 minutes, with walk breaks meaning participants spend about 60 percent of the session running. That ratio creates a clear way to practice changing gears without requiring continuous running throughout the workout.

Why the structure matters

For Siik, the value is in distributing the work. “Increasing workload (incline or speed) too quickly can lead to soreness or risk of injury,” he says. Small, progressive changes in speed or incline, he argues, produce a smoother rise in effort. The approach doesn’t remove the demands of hard training; it gives runners a rule for managing them.

There’s also a mental benefit to knowing what comes next. Siik calls the use of a repeated pattern “patternization,” saying that a well-structured sequence helps runners anticipate the next interval. That can keep attention on the session and make it easier to follow the intended effort rather than improvising each repetition.

“Once you experience really well-balanced intervals like this, it becomes very easy to know when something feels risky or too stressful on the body,” Siik says. That awareness may be the most useful part of the ladder: runners get a repeatable format, but they also get a framework for noticing when the workload has outpaced their ability to manage it. Start conservatively, keep the speed and grade in balance, and let the final incline reflect the effort you can sustain.