The Importance of Rest Intervals for Developing Speed (or Strength and Power)


Today I was sent an email that asked me to comment on the following workout that had been published on a very popular training and conditioning website as an appropriate workout for football players:

Complete the following sprints:

  • 2 x 20 Meter Sprints (rest 20 seconds between efforts)
  • Rest 30 seconds then…
  • 4 x 30 Meter Sprints (rest 30 seconds between efforts)
  • Rest 30 seconds then…
  • 10 x 10 Meter Flying Starts (rest 30 seconds between efforts)
  • take 10 meters to accelerate, you should be full speed by the time you hit your start.

What’s wrong with this picture? Well first, the volume of work done is fairly high. Not alarmingly so but pretty high for most athletes. The real problem though are the rest intervals. If this is supposed to be anything approaching speed work then the rest intervals are laughably short. As a point of reference, for acceleration development work for speed-power athletes I like to keep the rest intervals at about 1 minute per 10 meters run. That means even for a 20 meter run, the athlete should still be resting a full 2 minutes. For people who have never worked with speed-power athletes, and especially those who’ve never coached sprinters, jumpers, or hurdlers, this may seem like a joke….why would you need to rest for 2 minutes if you only sprinted for 20 meters (roughly 3 seconds)? The answer is because without sufficient rest you can’t possibly maintain the intensity needed to develop speed. Heck, with rest intervals as short as those listed in the workout above you aren’t even developing speed endurance because by about the second or third 30 meter sprint the quality of the runs would have deteriorated so much that you’d really only be developing the anaerobic glycolytic energy system which is not a contributing factor to true speed. By the time the athlete got to the 10 meter runs they’d more than likely be running at 70% of the intensity needed to train speed.

Real speed (or super heavy lifting, or high intensity plyometrics, etc) is primarily dependent on the efficiency of the neuromuscular system. And to both train at the intensities required to develop speed (or strength, explosiveness, power) or perform at a maximal level, the rest between subsequent efforts needs to be sufficient enough to ensure that one of the other systems of the human body is not a limiting factor. In the case of the workout above, the rest intervals are so ridiculously short that the athlete’s ATP (the fuel for most physiological activities) would NEVER have a chance to regenerate to sufficient levels between runs. As a result, the person would not be able to run at an intensity that is high enough to provide the type of stimulus that will produce adaptations in the nervous system (rate coding, conduction speed, activation level, etc) to actually develop speed (or strength, power, explosiveness). Even worse, the insufficient rest would ensure that technique would likely break down and the athlete would be rehearsing poor motor patterns. So all in all, the workout would be a surefire way to make the athlete either injured or slower.