Another fantastic topic!
Strength training is important for every human body. Specially as we age, as we lose muscle at a fast rate every year, so it takes strengthening to simply maintain muscle! Strength training is also key to strong bones. So overall, strength training is one of the best things you can do to have quality of life as you age.
However, the strength training I am referring to is weight training - as in - lifting iron! HIIT and Bootcamp are more cardio/endurance and not the same as lifting weights. Yes, it helps with developing muscles, but it is similar to endurance training - low weight, lots of reps. So while it works several parts of your body, it is not very different than cycling. As such, it might not be the best investment of your time. Although if you like it, go for it - but keep in mind that it is probably “competing” as opposed to “supporting” your cycling.
The strength training you should be aiming for is fewer reps and heavier weights - so yeah, those you do in the weight room. Those are also the ones that will benefit you the most on the bike.
@NUGirl this topic might interest you as well…