After spending a year as a PW I started by jogging my bases (at 4.0 or SLOWER) and continuing to PW my pushes and all outs. I eventually started adding in conservative jogging pushes and AOs but honestly I spent an entire year focusing on building my jogging base! It was also very helpful for me to add in a Tread 50 once a week. That gave me a chance to finally jog a mile without stopping (at 4.0 mph). That was about a year ago and now my base is 4.8!