The 12 x 800 is your focus workout for this week. You can improve the quality of these by adding some jogging to the rest interval. Instead of just walking for 3 min between each, you can walk for 20-30 steps and jog slowly for 20-30 steps. Stay smooth on these and enjoy the workout!
Stay with the times assigned on the next 800 workout (30 Aug). If you want to run 2-3 seconds faster during the middle 2-3 800s, go ahead. But stay smooth and keep your stride under control.
The 800 meter repeats can be run in 5 minutes. Walk for 3 minutes between each. It helps to pace yourself so that you are running the first 400 in 2:20, walk for 30 seconds and run the second lap [more quickly].
You had a really good 800 meter workout. Here is further instructions for next time:
1. Warm up with a gentle 10 min of run-walk-run
2. Do 4 gradual accelerations (not sprints)
3. At the beginning of each 800, start your watch and don't stop it until you finish the 800 meters. 800=5 min (not 5:30)
4. Walk for 20-30 seconds at the 400, but keep the watch running.
5. Walk for 4 minutes between each one.