I turned 46 on the day of my Whitney hike just to add to the fun.
I regularly jog 3 miles, 3 times a week. Usually a bit more. I live in So Cal so have access to lots of hills and mountains. I did do San Gorgonio (11,500) 2 weeks prior. But my biggest training probably comes from a well established trail almost in my backyard. It's 1000 ft in .75 miles. It's hard but short. Also walking lunges when ever I remember to. Down the driveway to get the paper, bedroom to kitchen etc. Then I try and do very little 5-7 days prior to a big hike. My body likes the rest.
I don't conserve water on the trail and have a mix of real food and powerbar gels and cliff bars. I unfortunately always over pack and started with 20 lbs and had 10 when I reweighed at the end.
I tend to use one treking pole. Had both in my pack until Trail Camp, then broke them out the rest of the trip. One for me and one for my friend.
And I was just probably lucky to not get altitude sickness. That was my real worry. Mileage and elevation gain didn't worry me, but I had never hiked over 11,500
