I think it depends how many hours you are doing. If you are doing a 650 hour season yes, but I think the lower hour plans don't give enough volume during base for a traditional LSD type training to work, I think you need more long rides in a week. However, I think that come the build periods most people could be slightly more effective with a touch less volume and more intensity than he prescribed. I followed a 650hr Friel plan real close last season, but had to deviate towards the end of the season due to the difficulty of the racing I was doing. My last block was short, September and October and was totally focused on one race. During that block I did a SST based plan and responded real well. This season I will be following more of that type of plan with a periodization twist to it. It really depends what you can endure, for me I don't get to mentally drained from a decent does of L4 and could probably do some type of L4 year around. Others may get burnt out from doing this.