Originally Posted by
Drew Eckhardt
30 second intervals don't work well except for making you faster 15-30 seconds at a time because they're powered mostly by your phosphocreatine energy system and type iix fast-twitch muscle fibers with relevant to speed after a minute.
7-10 minute intervals as hard as possible will do the most for VO2max (a few minutes) and lactate threshold (past an hour).
I'm just saying, I don't think "don't work well" is the consensus. Here's one link from google:
5 Cycling Workouts That Will Help You Get Fast Quickly : This Is Gonna Hurt | Bicycling
...Even 20- to 30-second micro-intervals have been shown to increase V02 max, burn fat, and improve endurance...
Other articles talk about longer time periods, but customized to your fitness level and genetics:
Interval Training | Bicycling
The way these things always go is, someone say "30 second intervals help with training", then other people go waaaaaaaaay overboard and make it into this big thing where they claim it's the only way to do it, when the original thing said "this is one of many options that can help" or "it's a good place to start".
But I think for someone who's not in good shape to begin with, 30 second intervals can definitely be a good place to start in improving speed.