Threshold Interval Duration?
I understand that the best intervals for improving your speed is to ride 2 x 20 minutes at threshold or just below, but would splitting this give the same effect, for example:
8 x 5 minute intervals with 2 minutes rest between each interval = 40 minutes at threshold
2 x 20 minute intervals with 10 minutes rest between each interval = 40 minutes at theshold
Would these workouts give the same benfit as they are both 40 minutes at threshold, or do you only get some of the gains as you are only riding 5 minutes at threshold instead of 20 minutes?
Im just trying to work out if more intervals but with the same overall threshold duration gives the same level of gains as the traditional 2 x 20 session?