just wanna share about the way i have been training for the last 8 months, it has led to a 5k PR
1`m 39 and i have been running for 12 years, my old 5k pr was 17:58 drunning around 40 miles a week on average, i recently ran 16:47 doing this:
monday to friday i commute to work running 5 miles in the morning and running 5 in the afternoon, 2-3 times a week the afternoon run is at threshold pace.
on weekends, i bike an hour on saturday and 90 minutes on sunday, i never run on weekends.
I`m thinking of increasing my weekday runs by a mile each way.
I find this method fun and effective.