I am a very dedicated alpinist who is looking to make a step into some larger alpine. I have been researching training methods for several years now and have a question about what you have found to be effective. The concepts you mentioned in Extreme Alpinism were very close to the kind of training I did as a college athlete and have been using that same method over the years. Just recently I have been researching the training methods through Crossfit. I enjoy the intensity and variability of the workouts, but I'm concerned that they are not improving my overall endurance for the extended periods required by the style of alpinism I prefer (long, fast, semi-technical routes). I have read the article you wrote about training for the ski mountaineering races and I'm wondering if you found you needed to supplement long endurance/aerobic workouts with the shorter anaerobic workouts similar to the CF excercises? I've found lots of info on the CF methods, and lots of info on training regimens similar to what you wrote about in Extreme Alpinism, but haven't found a cross-over. The CF method appeals to me because my obvious strength is my endurance/aerobic capacities and my need to develop more strength and muscle endurance. Thanks for your time.
You become what you do. If the intensity and variability of the short CF workout seduces you then you will develop the capacities that type of training provides. And if you do it long enough you'll pay for your newfound ability to go fast and hard with your previous ability to go long. I state explicitly in Ex Alp that a compromise effort in training is essential. Specific focus comes at a price.
That said, most alpine climbers would do well to add the athletic-type lifts and hard interval training to their programs because they are weak and under-powered but trick themselves into thinking they aren't. I say this because, generally, long isn't actually long, fast isn't truly fast, and hard is relative.
Having read the whole article (I presume you are referring to Endurance in the Knowledge section of the site) about the ski mountaineering races then you will have read this: "... it must be understood that these workouts were not undertaken in a vacuum; they were used to sharpen a 20-year endurance base gained by training and climbing at intensities specific to long endurance effort. The same results would not be produced in the athlete without a similar aerobic base and one downside of training exclusively at high intensity showed up quite quickly." And the following paragraphs hinting at the downside of a program with too much volume done at high intensity. With a few exceptions, those ski races are short (2-3 hours) and that's not alpinism.
If your (genuine) endurance is adequate because you have trained that energy system well, supplement by training in other areas without neglecting your endurance training altogether. If you are training for a sport-specific outcome then high intensity circuit training or interval weight training is not the one answer. It is a tool in the toolbox. High intensity effort should not comprise more than 5-8% of your total volume time-wise. And don't do junk training at mid-level efforts. You have four intensity levels to focus on: Recovery, Endurance, Threshold, Max Effort. How you split the work at any given time depends on your weaknesses. How you cycle and stack the intensity and volume depends on your objective and how smart you are about recovery. Learning and knowing this is your responsibility as an athlete.