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Intro: Sprints aren’t just for elite runners — they’re for anyone who wants to get fitter, faster, and more explosive. Short, sharp bursts of all-out effort can be transformative for both athletic performance and body composition.

In this RB100 challenge, the aim is to accumulate 100 seconds of total sprint time. Simple? Yes. Easy? Not quite.


How to Structure Your Sprint Intervals

You don’t need to sprint all 100 seconds in one go. Try one of these formats:

  • 10×10 seconds with 50–60 seconds rest between efforts
  • 5×20 seconds with 90 seconds rest
  • 4×25 seconds for more advanced athletes

Sprint types:

  • Outdoor sprints (track, hill, field)
  • Treadmill sprints
  • Assault bike or rower (high resistance)

Why It Works

  • Triggers fat-burning post-workout oxygen consumption (EPOC)
  • Trains explosive fast-twitch muscle fibres
  • Builds speed, power, and anaerobic endurance
  • Time-efficient: big gains, short sessions

Tips for Safety & Effectiveness

  • Always warm up thoroughly (mobility + build-up runs)
  • Use a soft surface (grass, turf, track) if possible
  • Maintain technique under fatigue — posture matters

Pair it with:


External Resources:

speed is a skill.

RB100.Fitness
Editorial Team

The Relentless Bravery Editorial Team brings together athletes, coaches, and experts to share trusted insights on training, recovery, and mindset. Always consult a professional before making fitness or health changes.

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