The Himalayan season starts from spring, and it's a big mountain with 8000 meters peaks.
Preparation for an 8000-meter peak expedition will involve a lot of three things: Duration, Consistency, and Elevation. Training without monitoring will easily revert to random exercise. Training records is needed to be examined on a dairy, weekly, annual basis. You can use the data on TrainingPeaks.com to measure and plan your training, different figure of different health stage will require different level of training to summit 8000 meter peaks.
Duration: By duration, I mean distribute weekly training time intelligently by a good training plan or an experience somebody, like a coach. Below you can see a chart that records the average weekly training time for 66 months leading up to the Himalayan climb. This climber spent 8.5 hours weekly for over 6 months. Note that there are a few weeks without records because she went to Aconcagua.
8.5 hours per week is only the average. It takes time to get to the fitness level whereby one can sustain a training load of 15+ hours per week. Not to mention the time spent for the transport to/from trailheads, prepping, showering, etc. The only way to keep up this kind of training volume if with consistency.
Weekly training records.
Training peaks account from October 1st, 2016 to June1st, 2017
Consistency: Thinks of the blue line, Chronic Training Load, as fitness. We are not machines, and this is not an exact science, so CTL isn't perfect for everyone, but is a very helpful representation. So how fit do you need to climb the Everest? In terms of the CTL: Denial 75, Everest 100, Everest without supplemental oxygen, 125.
It requires a CTL of 75 for 2 months to climb Denali, 100 for over 3 months to climb Everest. And 125+ CTL for at least 3 months to climb Everest without supplemental oxygen.
To get your CTL up that high a couple things need to deal with. It is well understood over a wide variety of sports that the maximum rate you can increase the trainer's CTL safely is 3-5 points per week. Hence to get to a CTL of 50 takes a minimum of 10 weeks. And that is for a young, healthy, adult. To get to 100, you need to 20-30 weeks of training in total. You can also work backyards or gm during spare time. From 30 to 100, an increase of 70 CTL points, you need 15-23 weeks. And then you need to keep that CTL for more than one month. Filnally, you need roughly fie months to get there and then 1-4 months to old that level while staying healthy, which requires considerable consistency.
Lastly Elevation: To some extent, we have to ho uphill for thousands of feet each week in order to get ready for mountaineering. Climbing requires different muscles than running flat/rolling terrain. Gluteus, hamstrings, musculature around the pelvis, all are used in different ways when you are doing uphill. Whether you do this outdoors, in stairwells, or on a treadmill, vertical elevation gain is essential.