For the next few months I am currently experimenting with a long block of threshold training with the hope of improving my threshold and climbing. I have already trained up to a peak in May and been able to get in some good blocks of training over the last eight months avg. about 15hrs weekly. I can usually now only get in around 8-9hrs per week(if I'm lucky) with threshold workouts twice a week i.e. 2x20 & 3x12 under/overs etc. Also some tempo & SST sessions i.e. 3x20 and one long 5-6hr LSD xc or road ride per week. I race mtb xc marathons 60-100miles, most of my training is either trainer or road based.
I am currently training and planning another peak for a 100mile xc race in Sep.
However at the minute and for the next 2-3 weeks It looks like I wont be able to get in any long rides

I've been able to get in some early back to back 90-120min SST trainer sessions over the weekend and plan on doing these whenever I can't fit in a LSD ride, this reduces my volume to about 7hrs weekly but with the slightly increased intensity the TSS is only slightly less.
Will I loose endurance and maybe start to de-train my aerobic base by missing the LSD rides? My limited time ensures that as a 42yo I get enough recovery between workouts ready to hit the next session but I don't want to throw in too much intensity into my week just yet as I like to include several VO2 sessions during the final build weeks before a race.
Any comments or thoughts on this?
