Benefits of High Intensity Interval Training

High Intensity Interval Training or HIIT is the latest trend in the fitness and running world. Some consider it a miracle exercise that will drastically improve endurance.

Below we take a look at high intensity interval training and how endurance runners should include it in their training programs.

What is High Intensity Interval Training ?

High Intensity Interval Training is a burst-and-recover style of cardiovascular training. It involves short “all out” bursts of exercise at 90-95% HRmax, with rest breaks of no or low intensity exercise in between each bout.

These intervals can be anywhere from 15s to 5 minutes. HIIT has been shown to significantly improve VO2max when compared to classic low intensity endurance training and lactate threshold training.

HIIT training vs. Low Intensity High Volume Training

Recent research suggest intervals of 4 minutes at 90-95% heart rate max maximise improvements in VO2max, compared to 15s intervals and low intensity endurance training.

A study by Helergud et al. (2007) found that an 8 week program of 3 HIIT sessions per week improved VO2max by 7.3%. This was an average improvement of 55.5 to 60.4, which is significant!

A recent review found that aerobic improvements from HIIT training compared to low intensity endurance training are amplified in older populations, populations with a lower baseline aerobic capacity and with longer HIIT intervals (Milanović et al., 2015).

When looking at well trained athletes, a polarised training protocol including both HIIT and low intensity endurance sessions had the most significant improvements in VO2max, time to exhaustion and peak velocity/power. This was compared to both a low intensity high volume and a HIIT only protocol (Stöggl et al, 2014).

They also suggest that initial improvements in VO2max from HIIT training usually occur in the first 6 weeks, therefore further blocks of HIIT training may not create any extra benefits.

HIIT Training Sessions for Runners

Below we have outlined HIIT session used in Stoggl et al. (2014) and Helgerud et al. (2007). This evidence based session has been proven to maximise VO2 max when completed 3 x per week for 6 weeks.

HIIT Training session:

  • Warm up: 20 minutes at 75% HR Max (Conversational pace)
  • Intervals: 4 x intervals of 4 minutes duration at 95% HR Max
  • Rest intervals: 3 minutes at 75% HR Max
  • Cool Down: 15 minutes at 75% HR Max

You can also read our article on polarised training programs to learn how best to incorporate HIIT into your program over a longer period.


Helgerud, J., Høydal, K., Wang, E., Karlsen, T., Berg, P., Bjerkaas, M., … & Hoff, J. (2007). Aerobic high-intensity intervals improve VO2max more than moderate training. Medicine & Science in Sports & Exercise39(4), 665-671.

Milanović, Z., Sporiš, G., & Weston, M. (2015). Effectiveness of high-intensity interval training (HIT) and continuous endurance training for VO 2max improvements: a systematic review and meta-analysis of controlled trials. Sports medicine, 45(10), 1469-1481.

Stöggl, T., & Sperlich, B. (2014). Polarized training has greater impact on key endurance variables than threshold, high intensity, or high volume training. Frontiers in physiology5, 33.

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