I’ve done a good bit of reading around and there is a lot of literature on detraining in professional and amateur atheletes.

But very little on to what extend it can be postponed or prevented by crosstraining.

I’ve picked up an SI joint injury that’s hard to kick and is preventing me from getting on the bike more than once a week, right in the middle of my build phase. I was doing 5-6hrs a week on the bike in intervals and now I can get one hour in, and the rest of my time is spent in the gym lifting, running and doing intervals on a rowing machine and crosstrainer. I’m likely to need to keep doing this for at least 2 months.

To what extent are traning gains sport-specific? Am I likely to lose much? If so – will it be at the aerobic, anaerobic or muscular endurance levels? A big impact on power curve?

Intereating.

My 2c…

Running: different muscle groups than cycling but the weight bearing is useful. Also can be physically quite traumatic in terms of muscle damage, though of course you recover. Good cardio.

Swimming: a good cross-training session as it’s easier in the legs & there is a slight therapeutic benefit as the water does massage the leg muscles a little. Downside is increased upper-body mass which is just more bulk to haul around on the bike. Good cardio, not so much weight bearing.

Weights: load-bearing & quite easy to target specific muscles, not much in the way of cardio though.

Other cross-training can include cross country skiing (awesome cardio, not too hard on the legs, load bearing & less upper body bulk to worry about). It’s probabky the best cross-training available but obviously not the easiest to access!

These are IMHO the easiest ones to access, except the skiing, there are no doubt other options.

Also, I suppose my second question would be: if on the bike, what would you focus on for that one session a week. Max power intervals, NM, Aerobic, Anaerobic?

Which one is going to take the biggest hit and need the longest to retrain if it did take a hit?