Medical Corner Training

Interval Training / Fast sessions for runners

Better performance and shorter training duration – these are two of the many advantages of interval training. If you want to increase your performance, there’s no getting around it.

The German elite runner Rudolf Harbig showed what interval training can achieve. In 1941, he beat the then world record in the 1000-meter race by two seconds. Two years earlier, he had already broken the world records in the 400 and 800 meters – an unprecedented triple.

His success – Harbig was famous for his final sprint – was due in part to interval training, which he was one of the pioneers to start. Today, the high-speed sessions are a permanent fixture in his training schedule. Ambitious runners who want to improve their performance cannot do without them.

Increase maximum oxygen uptake

Interval training is about combining short periods of high intensity exercise with short recovery periods. Your goal should be to get as close as possible to your maximum load limit, whether in endurance or strength.

Interval training is useful for several reasons:

  • You develop more speed endurance
  • You train very efficiently in a short period of time, so you can reduce your training volume and still improve your performance.
  • You increase your maximum oxygen uptake (VO2max)
  • You have more time for recovery thanks to interval training, therefore the risk of overuse injuries decreases.

Anaerobic threshold shifts

When you incorporate fast-paced sessions into your training schedule, your body will learn over time to take in more oxygen and use the available energy more efficiently. This will also shift your “anaerobic threshold” upward.

Above this threshold, runners consume more oxygen than they can breathe. In the anaerobic zone, the muscles produce lactate, which limits performance in the long run. If you can shift the anaerobic threshold from, for example, 165 to 175 heartbeats per minute, you can perform at high intensity for longer; at the same time, the oxygen debt and thus also the lactate increase is reduced. In other words, in the future you won’t incur oxygen debt until your heart rate reaches 175/minute. Moreover, thanks to the fast units, your body also learns to break down the accumulating lactate more quickly.

By the way, these processes can also be determined biologically: For example, good interval training increases the number of mitochondria in your muscle cells. They are responsible for providing energy.

Common mistake: A lot of training, but of poor quality

Many athletes make the mistake of training a lot, but not qualitatively well. They train for hours in the moderately intense range. This training combined with the time spent at work or with your family, leaves not enough time for recovery.

The result: performance decreases instead of increasing, and the athlete trains even more – a vicious circle that can eventually lead to overtraining and exhaustion. Muscle fatigue leads to overuse-related inflammation of tendon attachments, muscle fiber tears, or fatigue fractures of the bones.

Tempo runs

Tempo runs are a good way to train not only speed but also endurance. The pace should be based on race pace and the effort distance can be increased as the race goal approaches.

Expert tip: Interval training is more fun in a group.

Hill sprints are another option. They have the advantage of being less likely to result in injury, probably because the tendon stress is different and the pace is less intense than running on the flat. An example of hill sprint interval training would be to sprint up a fixed defined ramp at maximum speed and then run back down at a relaxed pace.

Plan for recovery afterwards

HIIT (high intensity interval training) is also used in strength/endurance training (Crossfit, etc.), here mostly as so-called Tabatas, named after Professor Izumi Tabata. In Tabatas, high-intensity units of (original) 20 to 40 seconds duration alternate with 10 to 20 second rests. This is often supported with appropriate music and timing.

Too many interval workouts should be avoided, however, so as not to overtax the body. One or two intense workouts per week is enough. You should plan the day after for (active) recovery.

Note: running.COACH plans the intensive workouts directly and individually into your plan. This way you can be sure to do enough intense runs and get the recovery you need afterwards.




Hardy Hüttemann, MD, specialist in physical medicine and rehabilitation, sports medicine SEMS, manual medicine SAMM, interventional pain therapy SSIPM, altitude and mountain medicine SGGM, head of Medical Center Basel Heuwaage.



Who is Medbase?

Medbase is the largest multidisciplinary sports medicine network in Switzerland and offers specialized sports medicine services for athletes, clubs and sports associations of all activity levels in the fields of sports medicine, sports physiotherapy, performance diagnostics and training advice.

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