During my weekly local "Power Advantage Program" training sessions I'm preaching/advocating Sweet Spot Training Intervals. Why? Because they work. i.e. they improve cycling performance. It doesn't take a rocket scientist to figure out that most of the physiological adaptations that are responsible for improve cycling performance are centered between the L2-L4 training zones/levels. Are you "Sweet Spot" Training? If not, you should be..because this is the PERFECT time of the year to be doing them.
For more information on Sweet Spot Training, please visit Coach Frank Overton's website: http://www.fascatcoaching.com/sweetspottraining.html