This post is inspired by the articles I have read about "yoga at your desk" and "exercise while you clean the house." I hate those articles because they invariably feature women taking care of household chores but not getting their own time to exercise.
With my train ride to work now 15 minutes longer (due to a job change, not SEPTA), I have learned that the commuter train can be a place to do balance exercises and oxygen deficit training, both of which could lead to better trail running fitness. Here's how:
Balance - Get on a peak train at the last stop before you enter or leave center city. Stand in the aisle without holding the seats around you, and just try not to fall as your train moves to North Philly. The swaying you feel will indicate that you are doing this right. This exercise is better than standing on the Bosu Ball. If you're a guy, young, or fit, you will notice that there are no seats for you anyway.
Oxygen Deficit - It turns out that even in Philly, you can do altitude training. Just hop on a SEPTA train during peak hours at the first or early stop before entering or leaving Center City. Take the inside seat. A smoker who just extinguished a cigarette, put on cologne/moose/perfume/BO, someone with bad breath who will talk on the phone, or a person just big enough to block out the air conditioning will sit next to you. You will naturally inhale less, turn your head towards the window or put your face inside a book, or whatever compensatory moves, which would all result in an oxygen deficit. When you get off the train and go on to the trails, it will feel like returning to sea level with low humidity.
I am bad. Just trying to look to the bright side.