as the weather's getting warmer, i'm looking to make a habit of pre-work rides.
i live 3 blocks from Central Park in NYC, which is a little over 6 miles per loop.
i haven't timed myself, but i think i could possibly get in 2 laps within a reasonable amount of time before work (i have a 1hr commute); about 13 miles total.

obviously 13mi is better than 0mi, but is it a decent workout?
at my ability level, the central park loop @ average 20-22mph is pretty challenging.
any suggestions are appreciated.