Seth DeMoor's 'Work Hard' Intervals

Workout - Seth DeMoor's 'Work Hard' Intervals

• 10min @ 6'00''/km
• 5 lots of:
  • 4min @ 4'30''/km
  • 1min @ 7'00''/km
• 10min @ 6'00''/km

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Intro

Take a closer look at WORK Hard (and rest), a session designed by pro runner Seth James DeMoor. This powerful workout builds strength and ensures your body stays primed between efforts. His video walks through the key details you’ll need to implement it yourself.

The Core Principles

• Power Training: Serious leg strength requires resistance. Seth uses 4-lb ankle weights while running steep mountain terrain—an advanced approach for concentrated strength development.
• Taper & Peak: With the Pikes Peak race 18 days away, Seth reduces his volume to recover properly. The objective: arrive race day feeling fresh, strong, and ready. These tapering principles apply whether you’re prepping for a mountain event or something different. Check out Mastering the 10K: Proven Training Plans, Pace Strategies, and How a Smart App Can Elevate Your Performance for tactics you can adapt to your own goal.
• The Workout Structure: Five 4-minute hard efforts separated by 1-minute recovery jogs form the core. The hard pace sits between a true easy effort and your tempo—quick enough to feel winded by the time each interval ends. Building stamina through this pattern is well-established, and if you want to explore other formats, our guide to Mastering Interval Training: Science-Backed Workouts and How a Smart App Can Personalize Them covers the range of options.
• Weekly Progression & Recovery: Seth’s schedule builds steadily toward a 25-minute run where his pace felt natural and sustainable. The plan also carves out a complete rest day and three walking days to support recovery.

The Workout

Here’s the 25-minute session breakdown:

Warm-up: 5–10 min easy jog

Main set (25 min total):
  • 4 min at a comfortably hard pace (aim to be winded by the end)
  • 1 min easy jog/recovery
  • Repeat 5× (total 20 min on + 5 min off)

Cool-down: 5–10 min easy jog

Adjust the hard pace to match your own fitness. The Pacing app makes it simple to structure and modify these intervals for your session.

Final Thoughts

Test this strength-focused interval workout, adjust the paces to where you are now, and protect those recovery days. Mountain runners aren’t the only ones who benefit—this structure works for building speed endurance across all distances. The same interval method appears in Mastering 5K Speed: Proven Interval Strategies to Cut Minutes off Your Time.

Pair hard sessions with proper recovery and you’ll build strength, arrive fresh, and perform at your best on race day—the same approach Seth uses. Enjoy the run.

References

• WORK Hard (and rest) - YouTube (YouTube Video)