Are 30 30 Intervals Good?

Research from Bent R. Rønnestad (here’s a video of a good lecture, for those interested) indicates that during maximum perceived exertion efforts, 30 second intervals with 15 seconds rest allow athletes to accumulate more time above 90% of VO2 max than 5 minute intervals.

Short intervals ranging from 10 to 40 seconds, with 1:1 or 2:1 work:recovery ratios, have been a staple of training programs since the 1990s, and were used less formally before that. In a study published in 1996, Dr. Izumi Tabata described a protocol of 20-second high intensity efforts separated by 10 seconds of recovery.

It’s really hard to keep yourself honest on an ALL OUT 5 minute effort. Max Aerobic intervals tend to fall in that classic 3-7 minute range. Sometimes a little shorter to start with, sometimes a little longer. With a 2:1 work to rest ratio (so 30/15, or 20/10), you can theoretically get more time in the zone, but there are a few issues with this.

I’d say race specific but not always about a race, sometimes just need to go hard for 2-5 min to make it over a hill or keep up with a buddy. More specifically, for indoor training I lean toward 30/30 or shorter VO2max intervals up to 4-5 min and then lengthen things out in to the 5-10 min range when riding moves outside.