Highly Intensive Interval Training (HIIT) with maximum effort blocks of 30 seconds can improve the performance of cyclists. When HIIT consists of maximum effort blocks of 5 minutes, the cycling performance will generally not improve. It appears that maximum effort in short blocks provides better workout results.


HIIT is a popular form of exercise to improve endurance performance. In order to design a HIIT training schedule there are several options when it comes to the total duration, the intensity and the length of the blocks exertion and rest between the blocks. Norwegian sports scientists have figured out the effect of short and long effort blocks on different bike performance measures.


This study involved two groups of trained cyclists with an average age of 33 years. Both groups did a HIIT workout 2 times a week for 10 weeks.

One group:

  • 9 cyclists, 30 sec group
  • Carried out the HIIT with maximum effort blocks of 30 seconds,
  • Followed by 15 seconds rest.

The other group:

  • 7 cyclists, 5 min group
  • carried out the HIIT with maximum effort blocks of 5 minutes,
  • Followed with 2:30 min of relative rest.

The relative rest was cycled at 50% of the power that has been achieved during maximal exercise blocks. Logically more power (363 W averages) was delivered during exercise blocks of 30 seconds than during the 5 min blocks (average 324 W). This also means that the relative rest blocks of the 30sec group were  average 19 W more intense than those of the 5min group. The total duration of the exercise units was similar for both groups as well as the perceived level of exhaustion after the HIIT. In between the HIIT-days both groups trained on their own low-intensity.

Before and after the 10 weeks of training all cyclists performed, on three test days, a maximal exercise tests for measuring the VO2max, the peak power, the average power during the 30 seconds Wingate test and the average power  during a 5 to 40 minute test. All tests and workouts were conducted on an ergometer bike or their own bike that was attached to equipment to measure power output.

The results show that both the power during the HIIT effort blocks, the VO2max and the peak power of the 30s group has improved with an average of 9%, and that these measures have not improved in the 5min group. In addition the power in the 30sec group improved during the Wingate test 5% on average and the power during the 5 minute test by an average of 8%. The aforementioned test measurements did not improve in the 5min-group. The power during the 40 minute test improved in the 30s group by 12% and in 5min group by 4%.


The results of this study show that trained cyclists who perform HIIT for 10 weeks 2 times per week with maximum effort blocks of 30 sec improve both endurance and sprint performance. In contrast to the cyclists of the 5 min-group who hardly improved. They can only show a slight improvement at the 40-minute test after HIIT-effort sessions with blocks of 5 min.  The reason therefore is, according to the researchers that this kind of training is not much different from the HIIT the athletes conducted already usually once a week. Cyclists can deliver more power during brief maximal exercise blocks; also the relative rest was more intense. This results in higher exercise intensity than during the long effort blocks. This higher intensity, however, did not lead to a higher perceived level of exhaustion. Because of this, it is to be recommended to carry out HIIT-effort sessions with short blocks. Keep in mind that this brief effort blocks give a greater load.