Hey there guys! My group consists of 4 people who enjoy backpacking. We are hoping to train for the Sierra coming up in July and for Mt Whitney next year. Hoping to look for one more person or couple to join us. Please send me an email or message if interested! =]
A lot of training comes before you get to any trail head - especially if it is a Sierra trail that begins near 10,000'. If you haven't been to high altitude backpacking, there are additional concerns to be aware of. Most of the ideas on getting fit in the health-fitness forum on this site apply.
I spend most of my time with a walk/jog program. Here is a handy link: exrx.net/Aerobic/JogWalkProgram.html. I don't have the time to daily get on a trail but I can work in an aerobic program at a gym - along with some weight training - and a bit of running on grass. The goal is to be able to jog for 20+ minutes and able to chat with your partner without gasping. The other is practicing "step breathing". Inhale on one footstep and exhale on the other. You can moderate your heart beat by taking shorter or longer steps and extend the time between gasping breaks in the action. Many breaks increases your time on the trail to get someplace as well as gives you too much time to reconsider what the heck you are doing there. Stopping anytime to take in the view and the experience is allowed however.
There are many trails on the eastern Sierra (US-395) that gets you to an overnight area for a late lunch. From there you can do some strenuous day hikes (including a 14,000' walk up) or additional backpacking over high passes to more conditioning hikes at 10,500 to 11,500' range. I don't know many who will say they wish they had taken less time to be fit for any hike.
By mid June usually there is snow covering Sierra trails from about 11,000' up. Almost all passes in the Sierra are over 11,000'. Many consider 'the season' to be mid-to-end of July thru August. Later in the summer allows the high passes to melt off some snow above 11,000' and to provide melt water for some beautiful flower displays at higher altitudes. Many here will be on the trails as soon as the trail heads are plowed - usually by early June. We have had a low snow season this year, so some passes/trails might be passable sooner by a couple of weeks. Passes will have had others before you getting successfully over it. Following their foot prints/sinks is certainly a plan.