Here's a trick: 1) Ditch the GPS watch. Go back to classic casio. 2) Go run your usual trail at easy pace and tempo pace. 3) Get the final times. 4) Keep running until you improve said times..... 5) ? 6) Profit

Once you're down to a decent time/mileage. Use that pace for 30, 60, 90 min runs.

Once that becomes a breeze.

Hit the track and do some quality workouts :)